diff --git a/scripts/check-node-all.sh b/scripts/check-node-all.sh
new file mode 100755
index 00000000000000..d878b88abe837d
--- /dev/null
+++ b/scripts/check-node-all.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+i=0
+j=0
+
+for x in $(find test/js/node/test/parallel -type f -name "test-$1*.js")
+do
+  i=$((i+1))
+  echo ./$x
+  if timeout 2 $PWD/build/debug/bun-debug ./$x
+  then
+    j=$((j+1))
+  fi
+  echo
+done
+
+echo $i tests tested
+echo $j tests passed
diff --git a/src/bun.js/ConsoleObject.zig b/src/bun.js/ConsoleObject.zig
index 12a2506a4132e0..1f517564d2483f 100644
--- a/src/bun.js/ConsoleObject.zig
+++ b/src/bun.js/ConsoleObject.zig
@@ -724,7 +724,6 @@ pub const FormatOptions = struct {
             if (try arg1.getBooleanLoose(globalThis, "sorted")) |opt| {
                 formatOptions.ordered_properties = opt;
             }
-
             if (try arg1.getBooleanLoose(globalThis, "compact")) |opt| {
                 formatOptions.single_line = opt;
             }
@@ -2148,7 +2147,7 @@ pub const Formatter = struct {
                     this.addForNewLine(description.len + "()".len);
                     writer.print(comptime Output.prettyFmt("<r><blue>Symbol({any})<r>", enable_ansi_colors), .{description});
                 } else {
-                    writer.print(comptime Output.prettyFmt("<r><blue>Symbol<r>", enable_ansi_colors), .{});
+                    writer.print(comptime Output.prettyFmt("<r><blue>Symbol()<r>", enable_ansi_colors), .{});
                 }
             },
             .Error => {
diff --git a/src/bun.js/api/BunObject.zig b/src/bun.js/api/BunObject.zig
index 13d6f66d791805..cc357501373502 100644
--- a/src/bun.js/api/BunObject.zig
+++ b/src/bun.js/api/BunObject.zig
@@ -535,6 +535,19 @@ pub fn inspect(globalThis: *JSC.JSGlobalObject, callframe: *JSC.CallFrame) bun.J
     return ret;
 }
 
+export fn Bun__inspect(globalThis: *JSGlobalObject, value: JSValue) ZigString {
+    // very stable memory address
+    var array = MutableString.init(getAllocator(globalThis), 0) catch unreachable;
+    var buffered_writer = MutableString.BufferedWriter{ .context = &array };
+    const writer = buffered_writer.writer();
+
+    var formatter = ConsoleObject.Formatter{ .globalThis = globalThis };
+    writer.print("{}", .{value.toFmt(&formatter)}) catch return ZigString.Empty;
+    buffered_writer.flush() catch return ZigString.Empty;
+
+    return ZigString.init(array.slice()).withEncoding();
+}
+
 pub fn getInspect(globalObject: *JSC.JSGlobalObject, _: *JSC.JSObject) JSC.JSValue {
     const fun = JSC.createCallback(globalObject, ZigString.static("inspect"), 2, inspect);
     var str = ZigString.init("nodejs.util.inspect.custom");
diff --git a/src/bun.js/bindings/ErrorCode.cpp b/src/bun.js/bindings/ErrorCode.cpp
index cd2ad0ee1fe16e..a00fb2fc4cb780 100644
--- a/src/bun.js/bindings/ErrorCode.cpp
+++ b/src/bun.js/bindings/ErrorCode.cpp
@@ -175,6 +175,9 @@ JSObject* createError(Zig::JSGlobalObject* globalObject, ErrorCode code, JSC::JS
     return createError(vm, globalObject, code, message);
 }
 
+// export fn Bun__inspect(globalThis: *JSGlobalObject, value: JSValue) ZigString
+extern "C" ZigString Bun__inspect(JSC::JSGlobalObject* globalObject, JSValue value);
+
 WTF::String JSValueToStringSafe(JSC::JSGlobalObject* globalObject, JSValue arg)
 {
     ASSERT(!arg.isEmpty());
@@ -201,14 +204,14 @@ WTF::String JSValueToStringSafe(JSC::JSGlobalObject* globalObject, JSValue arg)
         auto name = JSC::getCalculatedDisplayName(vm, cell->getObject());
         if (catchScope.exception()) {
             catchScope.clearException();
-            name = "Function"_s;
+            name = ""_s;
         }
 
         if (!name.isNull() && name.length() > 0) {
             return makeString("[Function: "_s, name, ']');
         }
 
-        return "Function"_s;
+        return "[Function: (anonymous)]"_s;
         break;
     }
 
@@ -217,34 +220,133 @@ WTF::String JSValueToStringSafe(JSC::JSGlobalObject* globalObject, JSValue arg)
     }
     }
 
-    return arg.toWTFStringForConsole(globalObject);
+    // return arg.toWTFString(globalObject); // this threw an exception on `{ __proto__: null }`
+    ZigString zstring = Bun__inspect(globalObject, arg);
+    BunString bstring(BunStringTag::ZigString, BunStringImpl(zstring));
+    return bstring.toWTFString();
+}
+
+WTF::String determineSpecificType(JSC::JSGlobalObject* globalObject, JSValue value)
+{
+    auto& vm = globalObject->vm();
+    auto scope = DECLARE_CATCH_SCOPE(vm);
+
+    if (value.isNull()) {
+        return String("null"_s);
+    }
+    if (value.isUndefined()) {
+        return String("undefined"_s);
+    }
+    if (value.isBigInt()) {
+        auto str = value.toStringOrNull(globalObject);
+        if (!str) return {};
+        return makeString("type bigint ("_s, str->getString(globalObject), "n)"_s);
+    }
+    if (value.isNumber()) {
+        double d = value.asNumber();
+        double infinity = std::numeric_limits<double>::infinity();
+        if (value == 0) return (1 / d == -infinity) ? String("type number (-0)"_s) : String("type number (0)"_s);
+        if (d != d) return String("type number (NaN)"_s);
+        if (d == infinity) return String("type number (Infinity)"_s);
+        if (d == -infinity) return String("type number (-Infinity)"_s);
+        auto str = value.toStringOrNull(globalObject);
+        if (!str) return {};
+        return makeString("type number ("_s, str->getString(globalObject), ")"_s);
+    }
+    if (value.isBoolean()) {
+        return value.asBoolean() ? String("type boolean (true)"_s) : String("type boolean (false)"_s);
+    }
+    if (value.isSymbol()) {
+        auto cell = value.asCell();
+        auto symbol = jsCast<Symbol*>(cell);
+        auto result = symbol->tryGetDescriptiveString();
+        auto description = result.has_value() ? result.value() : String("Symbol()"_s);
+        return makeString("type symbol ("_s, description, ")"_s);
+    }
+    if (value.isCallable()) {
+        auto& vm = globalObject->vm();
+        auto scope = DECLARE_CATCH_SCOPE(vm);
+        auto cell = value.asCell();
+        auto name = JSC::getCalculatedDisplayName(vm, cell->getObject());
+        if (scope.exception()) {
+            scope.clearException();
+            name = String(""_s);
+        }
+        if (!name.isNull() && name.length() > 0) {
+            return makeString("function "_s, name);
+        }
+        return String("function"_s);
+    }
+    if (value.isObject()) {
+        auto constructor = value.get(globalObject, vm.propertyNames->constructor);
+        RETURN_IF_EXCEPTION(scope, {});
+        if (constructor.toBoolean(globalObject)) {
+            auto name = constructor.get(globalObject, vm.propertyNames->name);
+            RETURN_IF_EXCEPTION(scope, {});
+            auto str = name.toString(globalObject);
+            RETURN_IF_EXCEPTION(scope, {});
+            return makeString("an instance of "_s, str->getString(globalObject));
+        }
+        // return `${lazyInternalUtilInspect().inspect(value, { depth: -1 })}`;
+        auto str = JSValueToStringSafe(globalObject, value);
+        RETURN_IF_EXCEPTION(scope, {});
+        return str;
+    }
+    if (value.isString()) {
+        auto str = value.toString(globalObject)->getString(globalObject);
+        if (str.length() > 28) {
+            str = str.substring(0, 25);
+            str = makeString(str, "..."_s);
+            if (!str.contains('\'')) {
+                return makeString("type string ('"_s, str, "')"_s);
+            }
+        }
+        //       return `type string (${JSONStringify(value)})`;
+        str = JSValueToStringSafe(globalObject, value);
+        RETURN_IF_EXCEPTION(scope, {});
+        return makeString("type string ("_s, str, ")"_s);
+    }
+
+    //       value = lazyInternalUtilInspect().inspect(value, { colors: false });
+    auto str = JSValueToStringSafe(globalObject, value);
+    RETURN_IF_EXCEPTION(scope, {});
+    return str;
 }
 
 namespace Message {
 
 WTF::String ERR_INVALID_ARG_TYPE(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, const StringView& arg_name, const StringView& expected_type, JSValue actual_value)
 {
-    auto actual_value_string = JSValueToStringSafe(globalObject, actual_value);
+    auto actual_value_string = determineSpecificType(globalObject, actual_value);
     RETURN_IF_EXCEPTION(scope, {});
 
-    return makeString("The \""_s, arg_name, "\" argument must be of type "_s, expected_type, ". Received: "_s, actual_value_string);
+    return makeString("The \""_s, arg_name, "\" argument must be of type "_s, expected_type, ". Received "_s, actual_value_string);
 }
 
 WTF::String ERR_INVALID_ARG_TYPE(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, const StringView& arg_name, ArgList expected_types, JSValue actual_value)
 {
     WTF::StringBuilder result;
 
-    auto actual_value_string = JSValueToStringSafe(globalObject, actual_value);
+    auto actual_value_string = determineSpecificType(globalObject, actual_value);
     RETURN_IF_EXCEPTION(scope, {});
 
-    result.append("The \""_s, arg_name, "\" argument must be of type "_s);
+    result.append("The "_s);
+
+    if (arg_name.contains(' ')) {
+        result.append(arg_name);
+    } else {
+        result.append("\""_s);
+        result.append(arg_name);
+        result.append("\" argument"_s);
+    }
+    result.append(" must be of type "_s);
 
     unsigned length = expected_types.size();
     if (length == 1) {
         result.append(expected_types.at(0).toWTFString(globalObject));
     } else if (length == 2) {
         result.append(expected_types.at(0).toWTFString(globalObject));
-        result.append(" or "_s);
+        result.append(", or "_s);
         result.append(expected_types.at(1).toWTFString(globalObject));
     } else {
         for (unsigned i = 0; i < length - 1; i++) {
@@ -253,11 +355,11 @@ WTF::String ERR_INVALID_ARG_TYPE(JSC::ThrowScope& scope, JSC::JSGlobalObject* gl
             JSValue expected_type = expected_types.at(i);
             result.append(expected_type.toWTFString(globalObject));
         }
-        result.append(" or "_s);
+        result.append(", or "_s);
         result.append(expected_types.at(length - 1).toWTFString(globalObject));
     }
 
-    result.append(". Received: "_s, actual_value_string);
+    result.append(". Received "_s, actual_value_string);
 
     return result.toString();
 }
@@ -295,20 +397,26 @@ WTF::String ERR_OUT_OF_RANGE(JSC::ThrowScope& scope, JSC::JSGlobalObject* global
     auto input = JSValueToStringSafe(globalObject, val_input);
     RETURN_IF_EXCEPTION(scope, {});
 
-    return makeString("The value of \""_s, arg_name, "\" is out of range. It must be "_s, range, ". Received: "_s, input);
+    return makeString("The value of \""_s, arg_name, "\" is out of range. It must be "_s, range, ". Received "_s, input);
 }
 
 }
 
 namespace ERR {
 
+JSC::EncodedJSValue throwCode(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, ErrorCode code, const WTF::String& message)
+{
+    throwScope.throwException(globalObject, createError(globalObject, code, message));
+    return {};
+}
+
 JSC::EncodedJSValue INVALID_ARG_TYPE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& arg_name, const WTF::String& expected_type, JSC::JSValue val_actual_value)
 {
     auto arg_kind = arg_name.startsWith("options."_s) ? "property"_s : "argument"_s;
     auto ty_first_char = expected_type[0];
     auto ty_kind = ty_first_char >= 'A' && ty_first_char <= 'Z' ? "an instance of"_s : "of type"_s;
 
-    auto actual_value = JSValueToStringSafe(globalObject, val_actual_value);
+    auto actual_value = determineSpecificType(globalObject, val_actual_value);
     RETURN_IF_EXCEPTION(throwScope, {});
 
     auto message = makeString("The \""_s, arg_name, "\" "_s, arg_kind, " must be "_s, ty_kind, " "_s, expected_type, ". Received "_s, actual_value);
@@ -324,7 +432,7 @@ JSC::EncodedJSValue INVALID_ARG_TYPE(JSC::ThrowScope& throwScope, JSC::JSGlobalO
     auto ty_first_char = expected_type[0];
     auto ty_kind = ty_first_char >= 'A' && ty_first_char <= 'Z' ? "an instance of"_s : "of type"_s;
 
-    auto actual_value = JSValueToStringSafe(globalObject, val_actual_value);
+    auto actual_value = determineSpecificType(globalObject, val_actual_value);
     RETURN_IF_EXCEPTION(throwScope, {});
 
     auto message = makeString("The \""_s, arg_name, "\" "_s, arg_kind, " must be "_s, ty_kind, " "_s, expected_type, ". Received "_s, actual_value);
@@ -397,7 +505,7 @@ JSC::EncodedJSValue OUT_OF_RANGE(JSC::ThrowScope& throwScope, JSC::JSGlobalObjec
     return {};
 }
 
-JSC::EncodedJSValue INVALID_ARG_VALUE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, WTF::ASCIILiteral name, JSC::JSValue value, const WTF::String& reason)
+JSC::EncodedJSValue INVALID_ARG_VALUE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& name, JSC::JSValue value, const WTF::String& reason)
 {
     ASCIILiteral type = String(name).find('.') != notFound ? "property"_s : "argument"_s;
 
@@ -442,8 +550,12 @@ JSC::EncodedJSValue STRING_TOO_LONG(JSC::ThrowScope& throwScope, JSC::JSGlobalOb
     return {};
 }
 
-JSC::EncodedJSValue BUFFER_OUT_OF_BOUNDS(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject)
+JSC::EncodedJSValue BUFFER_OUT_OF_BOUNDS(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& name)
 {
+    if (!name.isEmpty()) {
+        throwScope.throwException(globalObject, createError(globalObject, ErrorCode::ERR_BUFFER_OUT_OF_BOUNDS, makeString("\""_s, name, "\" is outside of buffer bounds"_s)));
+        return {};
+    }
     throwScope.throwException(globalObject, createError(globalObject, ErrorCode::ERR_BUFFER_OUT_OF_BOUNDS, "Attempt to access memory outside buffer bounds"_s));
     return {};
 }
diff --git a/src/bun.js/bindings/ErrorCode.h b/src/bun.js/bindings/ErrorCode.h
index a3f4f8a67eba91..accf7b56ae8b29 100644
--- a/src/bun.js/bindings/ErrorCode.h
+++ b/src/bun.js/bindings/ErrorCode.h
@@ -75,19 +75,21 @@ enum Bound {
 
 namespace ERR {
 
+JSC::EncodedJSValue throwCode(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, ErrorCode code, const WTF::String& message);
+
 JSC::EncodedJSValue INVALID_ARG_TYPE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& arg_name, const WTF::String& expected_type, JSC::JSValue val_actual_value);
-JSC::EncodedJSValue INVALID_ARG_TYPE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue arg_name, const WTF::String& expected_type, JSC::JSValue val_actual_value);
-JSC::EncodedJSValue OUT_OF_RANGE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& arg_name, double lower, double upper, JSC::JSValue actual);
-JSC::EncodedJSValue OUT_OF_RANGE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue arg_name, double lower, double upper, JSC::JSValue actual);
-JSC::EncodedJSValue OUT_OF_RANGE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue arg_name_val, double bound_num, Bound bound, JSC::JSValue actual);
+JSC::EncodedJSValue INVALID_ARG_TYPE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue val_arg_name, const WTF::String& val_expected_type, JSC::JSValue val_actual_value);
+JSC::EncodedJSValue OUT_OF_RANGE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& arg_name, size_t lower, size_t upper, JSC::JSValue actual);
+JSC::EncodedJSValue OUT_OF_RANGE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue arg_name, size_t lower, size_t upper, JSC::JSValue actual);
+JSC::EncodedJSValue OUT_OF_RANGE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue arg_name_val, size_t bound_num, Bound bound, JSC::JSValue actual);
 JSC::EncodedJSValue OUT_OF_RANGE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue arg_name_val, const WTF::String& msg, JSC::JSValue actual);
 JSC::EncodedJSValue OUT_OF_RANGE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& arg_name_val, const WTF::String& msg, JSC::JSValue actual);
-JSC::EncodedJSValue INVALID_ARG_VALUE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, WTF::ASCIILiteral name, JSC::JSValue value, const WTF::String& reason = "is invalid"_s);
+JSC::EncodedJSValue INVALID_ARG_VALUE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& name, JSC::JSValue value, const WTF::String& reason = "is invalid"_s);
 JSC::EncodedJSValue INVALID_ARG_VALUE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue name, JSC::JSValue value, const WTF::String& reason = "is invalid"_s);
 JSC::EncodedJSValue UNKNOWN_ENCODING(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& encoding);
 JSC::EncodedJSValue INVALID_STATE(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& statemsg);
 JSC::EncodedJSValue STRING_TOO_LONG(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject);
-JSC::EncodedJSValue BUFFER_OUT_OF_BOUNDS(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject);
+JSC::EncodedJSValue BUFFER_OUT_OF_BOUNDS(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, const WTF::String& name);
 JSC::EncodedJSValue UNKNOWN_SIGNAL(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue signal, bool triedUppercase = false);
 JSC::EncodedJSValue SOCKET_BAD_PORT(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* globalObject, JSC::JSValue name, JSC::JSValue port, bool allowZero);
 
diff --git a/src/bun.js/bindings/JSBuffer.cpp b/src/bun.js/bindings/JSBuffer.cpp
index fb0c0b5fe9dfb9..13ba5b51954242 100644
--- a/src/bun.js/bindings/JSBuffer.cpp
+++ b/src/bun.js/bindings/JSBuffer.cpp
@@ -77,6 +77,8 @@
 // #include <JavaScriptCore/JSTypedArrayViewPrototype.h>
 #include <JavaScriptCore/JSArrayBufferViewInlines.h>
 
+extern "C" bool Bun__Node__ZeroFillBuffers;
+
 using namespace JSC;
 using namespace WebCore;
 
@@ -210,6 +212,7 @@ static JSUint8Array* allocBuffer(JSC::JSGlobalObject* lexicalGlobalObject, size_
 
     return uint8Array;
 }
+
 static JSUint8Array* allocBufferUnsafe(JSC::JSGlobalObject* lexicalGlobalObject, size_t byteLength)
 {
 
@@ -248,7 +251,7 @@ static int normalizeCompareVal(int val, size_t a_length, size_t b_length)
     return val;
 }
 
-static inline WebCore::BufferEncodingType parseEncoding(JSC::JSGlobalObject* lexicalGlobalObject, JSC::ThrowScope& scope, JSValue arg)
+static WebCore::BufferEncodingType parseEncoding(JSC::ThrowScope& scope, JSC::JSGlobalObject* lexicalGlobalObject, JSValue arg, bool validateUnknown)
 {
     auto arg_ = arg.toStringOrNull(lexicalGlobalObject);
     RETURN_IF_EXCEPTION(scope, {});
@@ -256,6 +259,10 @@ static inline WebCore::BufferEncodingType parseEncoding(JSC::JSGlobalObject* lex
 
     std::optional<BufferEncodingType> encoded = parseEnumeration2(*lexicalGlobalObject, arg_s);
     if (UNLIKELY(!encoded)) {
+        if (validateUnknown) {
+            Bun::V::validateString(scope, lexicalGlobalObject, arg, "encoding"_s);
+            RETURN_IF_EXCEPTION(scope, WebCore::BufferEncodingType::utf8);
+        }
         Bun::ERR::UNKNOWN_ENCODING(scope, lexicalGlobalObject, arg_s);
         return WebCore::BufferEncodingType::utf8;
     }
@@ -263,6 +270,19 @@ static inline WebCore::BufferEncodingType parseEncoding(JSC::JSGlobalObject* lex
     return encoded.value();
 }
 
+JSC::EncodedJSValue validateOffset(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSC::JSValue value, JSC::JSValue name, JSC::JSValue min, JSC::JSValue max)
+{
+    if (min.isUndefined()) min = jsDoubleNumber(0);
+    if (max.isUndefined()) max = jsDoubleNumber(Bun::Buffer::kMaxLength);
+    return Bun::V::validateInteger(scope, globalObject, value, name, min, max);
+}
+JSC::EncodedJSValue validateOffset(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSC::JSValue value, const WTF::String& name, JSC::JSValue min, JSC::JSValue max)
+{
+    if (min.isUndefined()) min = jsDoubleNumber(0);
+    if (max.isUndefined()) max = jsDoubleNumber(Bun::Buffer::kMaxLength);
+    return Bun::V::validateInteger(scope, globalObject, value, name, min, max);
+}
+
 namespace WebCore {
 using namespace JSC;
 
@@ -426,11 +446,12 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_allocUnsafeBody(JS
     VM& vm = lexicalGlobalObject->vm();
     auto throwScope = DECLARE_THROW_SCOPE(vm);
     JSValue lengthValue = callFrame->argument(0);
-    Bun::V::validateNumber(throwScope, lexicalGlobalObject, lengthValue, jsString(vm, String("size"_s)), jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
+    Bun::V::validateNumber(throwScope, lexicalGlobalObject, lengthValue, "size"_s, jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
     RETURN_IF_EXCEPTION(throwScope, {});
     size_t length = lengthValue.toLength(lexicalGlobalObject);
     auto result = allocBufferUnsafe(lexicalGlobalObject, length);
     RETURN_IF_EXCEPTION(throwScope, {});
+    if (Bun__Node__ZeroFillBuffers) memset(result->typedVector(), 0, length);
     RELEASE_AND_RETURN(throwScope, JSValue::encode(result));
 }
 
@@ -442,7 +463,7 @@ static inline JSC::EncodedJSValue constructBufferEmpty(JSGlobalObject* lexicalGl
 
 static JSC::EncodedJSValue constructFromEncoding(JSGlobalObject* lexicalGlobalObject, JSString* str, WebCore::BufferEncodingType encoding)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);
 
     const auto& view = str->tryGetValue(lexicalGlobalObject);
@@ -513,7 +534,7 @@ static JSC::EncodedJSValue constructFromEncoding(JSGlobalObject* lexicalGlobalOb
 
 static inline JSC::EncodedJSValue constructBufferFromStringAndEncoding(JSC::JSGlobalObject* lexicalGlobalObject, JSValue arg0, JSValue arg1)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     WebCore::BufferEncodingType encoding = WebCore::BufferEncodingType::utf8;
 
     auto scope = DECLARE_THROW_SCOPE(vm);
@@ -546,10 +567,16 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_allocBody(JSC::JSG
     auto scope = DECLARE_THROW_SCOPE(vm);
 
     JSValue lengthValue = callFrame->argument(0);
-    Bun::V::validateNumber(scope, lexicalGlobalObject, lengthValue, jsString(vm, String("size"_s)), jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
+    Bun::V::validateNumber(scope, lexicalGlobalObject, lengthValue, "size"_s, jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
     RETURN_IF_EXCEPTION(scope, {});
     size_t length = lengthValue.toLength(lexicalGlobalObject);
 
+    if (length == 0) {
+        auto* uint8Array = createEmptyBuffer(lexicalGlobalObject);
+        RETURN_IF_EXCEPTION(scope, {});
+        RELEASE_AND_RETURN(scope, JSC::JSValue::encode(uint8Array));
+    }
+
     // fill argument
     if (UNLIKELY(callFrame->argumentCount() > 1)) {
         auto* uint8Array = createUninitializedBuffer(lexicalGlobalObject, length);
@@ -565,7 +592,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_allocBody(JSC::JSG
             if (callFrame->argumentCount() > 2) {
                 EnsureStillAliveScope arg2 = callFrame->uncheckedArgument(2);
                 if (!arg2.value().isUndefined()) {
-                    encoding = parseEncoding(lexicalGlobalObject, scope, arg2.value());
+                    encoding = parseEncoding(scope, lexicalGlobalObject, arg2.value(), true);
                     RETURN_IF_EXCEPTION(scope, {});
                 }
             }
@@ -579,8 +606,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_allocBody(JSC::JSG
             ZigString str = Zig::toZigString(str_);
 
             if (UNLIKELY(!Bun__Buffer_fill(&str, startPtr, end - start, encoding))) {
-                throwTypeError(lexicalGlobalObject, scope, "Failed to decode value"_s);
-                return {};
+                return Bun::ERR::throwCode(scope, lexicalGlobalObject, Bun::ErrorCode::ERR_INVALID_ARG_VALUE, "Failed to decode value"_s);
             }
         } else if (auto* view = JSC::jsDynamicCast<JSC::JSArrayBufferView*>(value)) {
             if (UNLIKELY(view->isDetached())) {
@@ -590,8 +616,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_allocBody(JSC::JSG
 
             size_t length = view->byteLength();
             if (UNLIKELY(length == 0)) {
-                throwTypeError(lexicalGlobalObject, scope, "Buffer cannot be empty"_s);
-                return {};
+                return Bun::ERR::throwCode(scope, lexicalGlobalObject, Bun::ErrorCode::ERR_INVALID_ARG_VALUE, "Buffer cannot be empty"_s);
             }
 
             auto* start = uint8Array->typedVector();
@@ -660,9 +685,10 @@ static inline JSC::EncodedJSValue jsBufferByteLengthFromStringAndEncoding(JSC::J
 
     return {};
 }
+
 static inline JSC::EncodedJSValue jsBufferConstructorFunction_byteLengthBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
 
     WebCore::BufferEncodingType encoding = WebCore::BufferEncodingType::utf8;
 
@@ -700,7 +726,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_byteLengthBody(JSC
 
 static inline JSC::EncodedJSValue jsBufferConstructorFunction_compareBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto throwScope = DECLARE_THROW_SCOPE(vm);
 
     auto castedThisValue = callFrame->argument(0);
@@ -748,20 +774,15 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_compareBody(JSC::J
 
 static inline JSC::EncodedJSValue jsBufferConstructorFunction_concatBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
 
     auto throwScope = DECLARE_THROW_SCOPE(vm);
-    if (callFrame->argumentCount() < 1) {
-        return constructBufferEmpty(lexicalGlobalObject);
-    }
 
-    auto arrayValue = callFrame->uncheckedArgument(0);
-    auto array = JSC::jsDynamicCast<JSC::JSArray*>(arrayValue);
-    if (!array) {
-        throwTypeError(lexicalGlobalObject, throwScope, "Argument must be an array"_s);
-        return {};
-    }
+    auto listValue = callFrame->argument(0);
 
+    Bun::V::validateArray(throwScope, lexicalGlobalObject, listValue, "list"_s, jsUndefined());
+    RETURN_IF_EXCEPTION(throwScope, {});
+    auto array = JSC::jsDynamicCast<JSC::JSArray*>(listValue);
     size_t arrayLength = array->length();
     if (arrayLength < 1) {
         RELEASE_AND_RETURN(throwScope, constructBufferEmpty(lexicalGlobalObject));
@@ -786,8 +807,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_concatBody(JSC::JS
 
         auto* typedArray = JSC::jsDynamicCast<JSC::JSUint8Array*>(element);
         if (!typedArray) {
-            throwTypeError(lexicalGlobalObject, throwScope, "Buffer.concat expects Uint8Array"_s);
-            return {};
+            return Bun::ERR::INVALID_ARG_TYPE(throwScope, lexicalGlobalObject, makeString("list["_s, i, "]"_s), "Buffer or Uint8Array"_s, element);
         }
 
         if (UNLIKELY(typedArray->isDetached())) {
@@ -835,7 +855,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_concatBody(JSC::JS
 
     size_t remain = byteLength;
     auto* head = outBuffer->typedVector();
-    const int arrayLengthI = arrayLength;
+    const int arrayLengthI = args.size();
     for (int i = 0; i < arrayLengthI && remain > 0; i++) {
         auto* typedArray = JSC::jsCast<JSC::JSUint8Array*>(args.at(i));
         size_t length = std::min(remain, typedArray->length());
@@ -856,7 +876,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_concatBody(JSC::JS
 // https://github.com/nodejs/node/blob/v22.9.0/lib/buffer.js#L337
 static inline JSC::EncodedJSValue jsBufferConstructorFunction_copyBytesFromBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto throwScope = DECLARE_THROW_SCOPE(vm);
 
     auto viewValue = callFrame->argument(0);
@@ -880,7 +900,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_copyBytesFromBody(
 
     if (!offsetValue.isUndefined() || !lengthValue.isUndefined()) {
         if (!offsetValue.isUndefined()) {
-            Bun::V::validateInteger(throwScope, lexicalGlobalObject, offsetValue, jsString(vm, String("offset"_s)), jsNumber(0), jsUndefined());
+            Bun::V::validateInteger(throwScope, lexicalGlobalObject, offsetValue, "offset"_s, jsNumber(0), jsUndefined());
             RETURN_IF_EXCEPTION(throwScope, {});
             offset = offsetValue.asNumber();
             if (offset >= viewLength) return JSValue::encode(createEmptyBuffer(lexicalGlobalObject));
@@ -890,7 +910,7 @@ static inline JSC::EncodedJSValue jsBufferConstructorFunction_copyBytesFromBody(
 
         double end = 0;
         if (!lengthValue.isUndefined()) {
-            Bun::V::validateInteger(throwScope, lexicalGlobalObject, lengthValue, jsString(vm, String("length"_s)), jsNumber(0), jsUndefined());
+            Bun::V::validateInteger(throwScope, lexicalGlobalObject, lengthValue, "length"_s, jsNumber(0), jsUndefined());
             RETURN_IF_EXCEPTION(throwScope, {});
             length = lengthValue.asNumber();
             end = offset + length;
@@ -960,7 +980,7 @@ STATIC_ASSERT_ISO_SUBSPACE_SHARABLE(JSBufferPrototype, JSBufferPrototype::Base);
 
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_compareBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto throwScope = DECLARE_THROW_SCOPE(vm);
 
     auto arg0 = callFrame->argument(0);
@@ -992,7 +1012,7 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_compareBody(JSC::JSG
     default:
         sourceEndValue = callFrame->uncheckedArgument(4);
         if (sourceEndValue != jsUndefined()) {
-            Bun::V::validateInteger(throwScope, lexicalGlobalObject, sourceEndValue, jsString(vm, String("sourceEnd"_s)), jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
+            Bun::V::validateInteger(throwScope, lexicalGlobalObject, sourceEndValue, "sourceEnd"_s, jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
             RETURN_IF_EXCEPTION(throwScope, {});
             sourceEnd = sourceEndValue.asNumber();
         }
@@ -1001,7 +1021,7 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_compareBody(JSC::JSG
     case 4:
         sourceStartValue = callFrame->uncheckedArgument(3);
         if (sourceStartValue != jsUndefined()) {
-            Bun::V::validateInteger(throwScope, lexicalGlobalObject, sourceStartValue, jsString(vm, String("sourceStart"_s)), jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
+            Bun::V::validateInteger(throwScope, lexicalGlobalObject, sourceStartValue, "sourceStart"_s, jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
             RETURN_IF_EXCEPTION(throwScope, {});
             sourceStart = sourceStartValue.asNumber();
         }
@@ -1010,7 +1030,7 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_compareBody(JSC::JSG
     case 3:
         targetEndValue = callFrame->uncheckedArgument(2);
         if (targetEndValue != jsUndefined()) {
-            Bun::V::validateInteger(throwScope, lexicalGlobalObject, targetEndValue, jsString(vm, String("targetEnd"_s)), jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
+            Bun::V::validateInteger(throwScope, lexicalGlobalObject, targetEndValue, "targetEnd"_s, jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
             RETURN_IF_EXCEPTION(throwScope, {});
             targetEnd = targetEndValue.asNumber();
         }
@@ -1019,7 +1039,7 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_compareBody(JSC::JSG
     case 2:
         targetStartValue = callFrame->uncheckedArgument(1);
         if (targetStartValue != jsUndefined()) {
-            Bun::V::validateInteger(throwScope, lexicalGlobalObject, targetStartValue, jsString(vm, String("targetStart"_s)), jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
+            Bun::V::validateInteger(throwScope, lexicalGlobalObject, targetStartValue, "targetStart"_s, jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
             RETURN_IF_EXCEPTION(throwScope, {});
             targetStart = targetStartValue.asNumber();
         }
@@ -1072,7 +1092,7 @@ static double toInteger(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObjec
 // https://github.com/nodejs/node/blob/v22.9.0/lib/buffer.js#L205
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_copyBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto throwScope = DECLARE_THROW_SCOPE(vm);
 
     auto targetValue = callFrame->argument(0);
@@ -1138,7 +1158,7 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_copyBody(JSC::JSGlob
 
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_equalsBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto throwScope = DECLARE_THROW_SCOPE(vm);
     if (callFrame->argumentCount() < 1) {
         throwVMError(lexicalGlobalObject, throwScope, createNotEnoughArgumentsError(lexicalGlobalObject));
@@ -1170,9 +1190,10 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_equalsBody(JSC::JSGl
 
     RELEASE_AND_RETURN(throwScope, JSC::JSValue::encode(JSC::jsBoolean(normalizeCompareVal(result, a_length, b_length) == 0)));
 }
+
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_fillBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);
 
     if (callFrame->argumentCount() < 1) {
@@ -1211,20 +1232,19 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_fillBody(JSC::JSGlob
     }
 
     if (!encodingValue.isUndefined() && value.isString()) {
-        if (!encodingValue.isString()) return Bun::ERR::INVALID_ARG_TYPE(scope, lexicalGlobalObject, "encoding"_s, "string"_s, encodingValue);
-        encoding = parseEncoding(lexicalGlobalObject, scope, encodingValue);
+        encoding = parseEncoding(scope, lexicalGlobalObject, encodingValue, true);
         RETURN_IF_EXCEPTION(scope, {});
     }
 
     // https://github.com/nodejs/node/blob/v22.9.0/lib/buffer.js#L1066-L1079
     // https://github.com/nodejs/node/blob/v22.9.0/lib/buffer.js#L122
     if (!offsetValue.isUndefined()) {
-        Bun::V::validateNumber(scope, lexicalGlobalObject, offsetValue, jsString(vm, String("offset"_s)), jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
+        Bun::V::validateNumber(scope, lexicalGlobalObject, offsetValue, "offset"_s, jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
         RETURN_IF_EXCEPTION(scope, {});
         offset = offsetValue.toLength(lexicalGlobalObject);
     }
     if (!endValue.isUndefined()) {
-        Bun::V::validateNumber(scope, lexicalGlobalObject, endValue, jsString(vm, String("end"_s)), jsNumber(0), jsNumber(limit));
+        Bun::V::validateNumber(scope, lexicalGlobalObject, endValue, "end"_s, jsNumber(0), jsNumber(limit));
         RETURN_IF_EXCEPTION(scope, {});
         end = endValue.toLength(lexicalGlobalObject);
     }
@@ -1255,8 +1275,7 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_fillBody(JSC::JSGlob
 
         size_t length = view->byteLength();
         if (UNLIKELY(length == 0)) {
-            throwTypeError(lexicalGlobalObject, scope, "Buffer cannot be empty"_s);
-            return {};
+            return Bun::ERR::throwCode(scope, lexicalGlobalObject, Bun::ErrorCode::ERR_INVALID_ARG_VALUE, "Buffer cannot be empty"_s);
         }
 
         length = std::min(length, remain);
@@ -1300,6 +1319,28 @@ static int64_t indexOf(const uint8_t* thisPtr, int64_t thisLength, const uint8_t
     return -1;
 }
 
+static int64_t indexOf16(const uint8_t* thisPtr, int64_t thisLength, const uint8_t* valuePtr, int64_t valueLength, int64_t byteOffset)
+{
+    size_t finalresult = 0;
+    if (thisLength == 1) return -1;
+    thisLength = thisLength / 2 * 2;
+    if (valueLength == 1) return -1;
+    valueLength = valueLength / 2 * 2;
+    byteOffset = byteOffset / 2 * 2;
+    while (true) {
+        auto res = indexOf(thisPtr, thisLength, valuePtr, valueLength, byteOffset);
+        if (res == -1) return -1;
+        if (res % 2 == 1) {
+            thisPtr += res + 1;
+            thisLength -= res + 1;
+            finalresult += res + 1;
+            continue;
+        }
+        finalresult += res;
+        return finalresult;
+    }
+}
+
 static int64_t lastIndexOf(const uint8_t* thisPtr, int64_t thisLength, const uint8_t* valuePtr, int64_t valueLength, int64_t byteOffset)
 {
     auto start = thisPtr;
@@ -1311,108 +1352,128 @@ static int64_t lastIndexOf(const uint8_t* thisPtr, int64_t thisLength, const uin
     return -1;
 }
 
-static int64_t indexOf(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis, bool last)
+static ssize_t indexOfOffset(size_t length, ssize_t offset_i64, ssize_t needle_length, bool is_forward)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
-    auto scope = DECLARE_THROW_SCOPE(vm);
-    if (callFrame->argumentCount() < 1) {
-        throwVMError(lexicalGlobalObject, scope, createNotEnoughArgumentsError(lexicalGlobalObject));
-        return -1;
+    ssize_t length_i64 = static_cast<ssize_t>(length);
+    if (offset_i64 < 0) {
+        if (offset_i64 + length_i64 >= 0) {
+            // Negative offsets count backwards from the end of the buffer.
+            return length_i64 + offset_i64;
+        } else if (is_forward || needle_length == 0) {
+            // indexOf from before the start of the buffer: search the whole buffer.
+            return 0;
+        } else {
+            // lastIndexOf from before the start of the buffer: no match.
+            return -1;
+        }
+    } else {
+        if (offset_i64 + needle_length <= length_i64) {
+            // Valid positive offset.
+            return offset_i64;
+        } else if (needle_length == 0) {
+            // Out of buffer bounds, but empty needle: point to end of buffer.
+            return length_i64;
+        } else if (is_forward) {
+            // indexOf from past the end of the buffer: no match.
+            return -1;
+        } else {
+            // lastIndexOf from past the end of the buffer: search the whole buffer.
+            return length_i64 - 1;
+        }
     }
+}
 
-    auto value = callFrame->uncheckedArgument(0);
-    WebCore::BufferEncodingType encoding = WebCore::BufferEncodingType::utf8;
+static int64_t indexOf(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter buffer, bool last)
+{
+    auto& vm = lexicalGlobalObject->vm();
+    auto scope = DECLARE_THROW_SCOPE(vm);
+    bool dir = !last;
+    const uint8_t* typedVector = buffer->typedVector();
+    size_t byteLength = buffer->byteLength();
+    std::optional<BufferEncodingType> encoding = std::nullopt;
 
-    int64_t length = static_cast<int64_t>(castedThis->byteLength());
-    const uint8_t* typedVector = castedThis->typedVector();
+    if (byteLength == 0) return -1;
 
-    int64_t byteOffset = last ? length - 1 : 0;
+    auto valueValue = callFrame->argument(0);
+    auto byteOffsetValue = callFrame->argument(1);
+    auto encodingValue = callFrame->argument(2);
 
-    if (callFrame->argumentCount() > 1) {
-        EnsureStillAliveScope arg1 = callFrame->uncheckedArgument(1);
-        if (arg1.value().isString()) {
-            encoding = parseEncoding(lexicalGlobalObject, scope, arg1.value());
-            RETURN_IF_EXCEPTION(scope, -1);
-        } else {
-            auto byteOffset_ = arg1.value().toNumber(lexicalGlobalObject);
-            RETURN_IF_EXCEPTION(scope, -1);
-
-            if (std::isnan(byteOffset_) || std::isinf(byteOffset_)) {
-                byteOffset = last ? length - 1 : 0;
-            } else if (byteOffset_ < 0) {
-                byteOffset = length + static_cast<int64_t>(byteOffset_);
-            } else {
-                byteOffset = static_cast<int64_t>(byteOffset_);
-            }
+    if (byteOffsetValue.isString()) {
+        encodingValue = byteOffsetValue;
+        byteOffsetValue = jsUndefined();
+    } else {
+        double byteOffset = byteOffsetValue.toNumber(lexicalGlobalObject);
+        RETURN_IF_EXCEPTION(scope, -1);
+        if (byteOffset > 0x7fffffffp0f) byteOffsetValue = jsDoubleNumber(0x7fffffffp0f);
+        if (byteOffset < -0x80000000p0f) byteOffsetValue = jsDoubleNumber(-0x80000000p0f);
+    }
 
-            if (last) {
-                if (byteOffset < 0) {
-                    return -1;
-                } else if (byteOffset > length - 1) {
-                    byteOffset = length - 1;
-                }
-            } else {
-                if (byteOffset <= 0) {
-                    byteOffset = 0;
-                } else if (byteOffset > length - 1) {
-                    return -1;
-                }
-            }
+    byteOffsetValue = jsDoubleNumber(byteOffsetValue.toNumber(lexicalGlobalObject));
+    RETURN_IF_EXCEPTION(scope, -1);
+    if (std::isnan(byteOffsetValue.asNumber())) byteOffsetValue = jsNumber(dir ? 0 : byteLength);
 
-            if (callFrame->argumentCount() > 2) {
-                EnsureStillAliveScope encodingValue = callFrame->uncheckedArgument(2);
-                if (!encodingValue.value().isUndefined()) {
-                    encoding = parseEncoding(lexicalGlobalObject, scope, encodingValue.value());
-                    RETURN_IF_EXCEPTION(scope, -1);
-                }
+    if (valueValue.isNumber()) {
+        ssize_t byteOffset = indexOfOffset(byteLength, byteOffsetValue.asNumber(), 1, dir);
+        if (byteOffset == -1) return -1;
+        uint8_t byteValue = (valueValue.toInt32(lexicalGlobalObject)) % 256;
+        RETURN_IF_EXCEPTION(scope, -1);
+        if (last) {
+            for (int64_t i = byteOffset; i >= 0; --i) {
+                if (byteValue == typedVector[i]) return i;
             }
+        } else {
+            const void* offset = memchr(reinterpret_cast<const void*>(typedVector + byteOffset), byteValue, byteLength - byteOffset);
+            if (offset != NULL) return static_cast<const uint8_t*>(offset) - typedVector;
         }
+        return -1;
     }
 
-    if (value.isString()) {
-        auto* str = value.toStringOrNull(lexicalGlobalObject);
-        RETURN_IF_EXCEPTION(scope, -1);
+    WTF::String encodingString;
+    if (!encodingValue.isUndefined()) {
+        encodingString = encodingValue.toWTFString(lexicalGlobalObject);
+        RETURN_IF_EXCEPTION(scope, {});
+        encoding = parseEnumeration2(*lexicalGlobalObject, encodingString);
+    } else {
+        encoding = BufferEncodingType::utf8;
+    }
 
-        JSC::EncodedJSValue encodedBuffer = constructFromEncoding(lexicalGlobalObject, str, encoding);
+    if (valueValue.isString()) {
+        if (!encoding.has_value()) {
+            return Bun::ERR::UNKNOWN_ENCODING(scope, lexicalGlobalObject, encodingString);
+        }
+        auto* str = valueValue.toStringOrNull(lexicalGlobalObject);
+        RETURN_IF_EXCEPTION(scope, -1);
+        ssize_t byteOffset = indexOfOffset(byteLength, byteOffsetValue.asNumber(), str->length(), dir);
+        if (byteOffset == -1) return -1;
+        if (str->length() == 0) return byteOffset;
+        JSC::EncodedJSValue encodedBuffer = constructFromEncoding(lexicalGlobalObject, str, encoding.value());
         auto* arrayValue = JSC::jsDynamicCast<JSC::JSUint8Array*>(JSC::JSValue::decode(encodedBuffer));
         int64_t lengthValue = static_cast<int64_t>(arrayValue->byteLength());
         const uint8_t* typedVectorValue = arrayValue->typedVector();
         if (last) {
-            return lastIndexOf(typedVector, length, typedVectorValue, lengthValue, byteOffset);
+            return lastIndexOf(typedVector, byteLength, typedVectorValue, lengthValue, byteOffset);
         } else {
-            return indexOf(typedVector, length, typedVectorValue, lengthValue, byteOffset);
-        }
-    } else if (value.isNumber()) {
-        uint8_t byteValue = static_cast<uint8_t>((value.toInt32(lexicalGlobalObject)) % 256);
-        RETURN_IF_EXCEPTION(scope, -1);
-
-        if (last) {
-            for (int64_t i = byteOffset; i >= 0; --i) {
-                if (byteValue == typedVector[i]) {
-                    return i;
-                }
-            }
-        } else {
-            const void* offset = memchr(reinterpret_cast<const void*>(typedVector + byteOffset), byteValue, length - byteOffset);
-            if (offset != NULL) {
-                return static_cast<int64_t>(static_cast<const uint8_t*>(offset) - typedVector);
-            }
+            if (encoding.value() == BufferEncodingType::ucs2) return indexOf16(typedVector, byteLength, typedVectorValue, lengthValue, byteOffset);
+            return indexOf(typedVector, byteLength, typedVectorValue, lengthValue, byteOffset);
         }
+    }
 
-        return -1;
-    } else if (auto* arrayValue = JSC::jsDynamicCast<JSC::JSUint8Array*>(value)) {
-        size_t lengthValue = arrayValue->byteLength();
-        const uint8_t* typedVectorValue = arrayValue->typedVector();
+    if (auto* array = JSC::jsDynamicCast<JSC::JSUint8Array*>(valueValue)) {
+        if (!encoding.has_value()) encoding = BufferEncodingType::utf8;
+        size_t lengthValue = array->byteLength();
+        ssize_t byteOffset = indexOfOffset(byteLength, byteOffsetValue.asNumber(), lengthValue, dir);
+        if (byteOffset == -1) return -1;
+        if (lengthValue == 0) return byteOffset;
+        const uint8_t* typedVectorValue = array->typedVector();
         if (last) {
-            return lastIndexOf(typedVector, length, typedVectorValue, lengthValue, byteOffset);
+            return lastIndexOf(typedVector, byteLength, typedVectorValue, lengthValue, byteOffset);
         } else {
-            return indexOf(typedVector, length, typedVectorValue, lengthValue, byteOffset);
+            if (encoding.value() == BufferEncodingType::ucs2) return indexOf16(typedVector, byteLength, typedVectorValue, lengthValue, byteOffset);
+            return indexOf(typedVector, byteLength, typedVectorValue, lengthValue, byteOffset);
         }
-    } else {
-        throwTypeError(lexicalGlobalObject, scope, "Invalid value type"_s);
-        return -1;
     }
 
+    Bun::ERR::INVALID_ARG_TYPE(scope, lexicalGlobalObject, "value"_s, "number, string, Buffer, or Uint8Array"_s, valueValue);
     return -1;
 }
 
@@ -1421,19 +1482,22 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_includesBody(JSC::JS
     auto index = indexOf(lexicalGlobalObject, callFrame, castedThis, false);
     return JSC::JSValue::encode(jsBoolean(index != -1));
 }
+
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_indexOfBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
     auto index = indexOf(lexicalGlobalObject, callFrame, castedThis, false);
     return JSC::JSValue::encode(jsNumber(index));
 }
+
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_lastIndexOfBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
     auto index = indexOf(lexicalGlobalObject, callFrame, castedThis, true);
     return JSC::JSValue::encode(jsNumber(index));
 }
+
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_swap16Body(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);
 
     constexpr int elemSize = 2;
@@ -1460,9 +1524,10 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_swap16Body(JSC::JSGl
 
     return JSC::JSValue::encode(castedThis);
 }
+
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_swap32Body(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);
 
     constexpr int elemSize = 4;
@@ -1494,9 +1559,10 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_swap32Body(JSC::JSGl
 
     return JSC::JSValue::encode(castedThis);
 }
+
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_swap64Body(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);
 
     constexpr size_t elemSize = 8;
@@ -1623,7 +1689,7 @@ bool inline parseArrayIndex(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalO
 // using byteLength and byte offsets here is intentional
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_toStringBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);
     uint32_t start = 0;
     uint32_t end = castedThis->byteLength();
@@ -1643,7 +1709,7 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_toStringBody(JSC::JS
         return jsBufferToString(vm, lexicalGlobalObject, castedThis, start, end, encoding);
 
     if (!arg1.isUndefined()) {
-        encoding = parseEncoding(lexicalGlobalObject, scope, arg1);
+        encoding = parseEncoding(scope, lexicalGlobalObject, arg1, false);
         RETURN_IF_EXCEPTION(scope, {});
     }
 
@@ -1677,7 +1743,7 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_toStringBody(JSC::JS
 template<BufferEncodingType encoding>
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_SliceWithEncoding(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);
     auto* castedThis = JSC::jsDynamicCast<JSC::JSArrayBufferView*>(callFrame->thisValue());
     const JSValue startValue = callFrame->argument(0);
@@ -1769,7 +1835,7 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunction_writeEncodingBody(JS
 template<BufferEncodingType encoding>
 static inline JSC::EncodedJSValue jsBufferPrototypeFunctionWriteWithEncoding(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
+    auto& vm = lexicalGlobalObject->vm();
     auto scope = DECLARE_THROW_SCOPE(vm);
     auto* castedThis = JSC::jsDynamicCast<JSC::JSArrayBufferView*>(callFrame->thisValue());
 
@@ -1794,93 +1860,64 @@ static inline JSC::EncodedJSValue jsBufferPrototypeFunctionWriteWithEncoding(JSC
 
 static inline JSC::EncodedJSValue jsBufferPrototypeFunction_writeBody(JSC::JSGlobalObject* lexicalGlobalObject, JSC::CallFrame* callFrame, typename IDLOperation<JSArrayBufferView>::ClassParameter castedThis)
 {
-    auto& vm = JSC::getVM(lexicalGlobalObject);
-    uint32_t offset = 0;
-    uint32_t length = castedThis->byteLength();
-    uint32_t max = length;
-    WebCore::BufferEncodingType encoding = WebCore::BufferEncodingType::utf8;
+    auto& vm = lexicalGlobalObject->vm();
 
     auto scope = DECLARE_THROW_SCOPE(vm);
 
-    if (UNLIKELY(callFrame->argumentCount() == 0)) {
-        throwTypeError(lexicalGlobalObject, scope, "Not enough arguments"_s);
-        return {};
-    }
-
-    EnsureStillAliveScope arg0 = callFrame->argument(0);
-    auto* str = arg0.value().toStringOrNull(lexicalGlobalObject);
-    if (!str) {
-        throwTypeError(lexicalGlobalObject, scope, "write() expects a string"_s);
-        return {};
-    }
-
-    JSValue offsetValue = jsUndefined();
-    JSValue lengthValue = jsUndefined();
-    JSValue encodingValue = jsUndefined();
-
-    switch (callFrame->argumentCount()) {
-    case 4:
-        encodingValue = callFrame->uncheckedArgument(3);
-        FALLTHROUGH;
-    case 3:
-        lengthValue = callFrame->uncheckedArgument(2);
-        FALLTHROUGH;
-    case 2:
-        offsetValue = callFrame->uncheckedArgument(1);
-        break;
-    default:
-        break;
-    }
-
-    auto setEncoding = [&]() {
-        if (!encodingValue.isUndefined()) {
-            encoding = parseEncoding(lexicalGlobalObject, scope, encodingValue);
-        }
-    };
+    auto stringValue = callFrame->argument(0);
+    auto offsetValue = callFrame->argument(1);
+    auto lengthValue = callFrame->argument(2);
+    auto encodingValue = callFrame->argument(3);
 
     if (offsetValue.isUndefined()) {
-        // https://github.com/nodejs/node/blob/e676942f814915b2d24fc899bb42dc71ae6c8226/lib/buffer.js#L1053
-        RELEASE_AND_RETURN(scope, writeToBuffer(lexicalGlobalObject, castedThis, str, offset, length, encoding));
+        Bun::V::validateString(scope, lexicalGlobalObject, stringValue, "string"_s);
+        RETURN_IF_EXCEPTION(scope, {});
+        auto* str = stringValue.toString(lexicalGlobalObject);
+        uint32_t offset = 0;
+        uint32_t length = castedThis->byteLength();
+        RELEASE_AND_RETURN(scope, writeToBuffer(lexicalGlobalObject, castedThis, str, offset, length, WebCore::BufferEncodingType::utf8));
     }
-
     if (lengthValue.isUndefined() && offsetValue.isString()) {
-        // https://github.com/nodejs/node/blob/e676942f814915b2d24fc899bb42dc71ae6c8226/lib/buffer.js#L1056
         encodingValue = offsetValue;
-        setEncoding();
+        lengthValue = jsNumber(castedThis->byteLength());
+        offsetValue = jsNumber(0);
+    } else {
+        uint32_t length = castedThis->byteLength();
+        validateOffset(scope, lexicalGlobalObject, offsetValue, "offset"_s, jsNumber(0), jsNumber(length));
         RETURN_IF_EXCEPTION(scope, {});
-        RELEASE_AND_RETURN(scope, writeToBuffer(lexicalGlobalObject, castedThis, str, offset, length, encoding));
-    }
+        uint32_t offset = offsetValue.toUInt32(lexicalGlobalObject);
+        RETURN_IF_EXCEPTION(scope, {});
+        uint32_t remaining = castedThis->byteLength() - offset;
 
-    if (UNLIKELY(!offsetValue.isNumber())) {
-        throwTypeError(lexicalGlobalObject, scope, "Invalid offset"_s);
-        return {};
+        if (lengthValue.isUndefined()) {
+            lengthValue = jsNumber(remaining);
+        } else if (lengthValue.isString()) {
+            encodingValue = lengthValue;
+            lengthValue = jsNumber(remaining);
+        } else {
+            validateOffset(scope, lexicalGlobalObject, lengthValue, "length"_s, jsNumber(0), jsNumber(length));
+            RETURN_IF_EXCEPTION(scope, {});
+            length = lengthValue.toUInt32(lexicalGlobalObject);
+            RETURN_IF_EXCEPTION(scope, {});
+            if (length > remaining) lengthValue = jsNumber(remaining);
+        }
     }
 
-    int32_t userOffset = offsetValue.toInt32(lexicalGlobalObject);
+    Bun::V::validateString(scope, lexicalGlobalObject, stringValue, "string"_s);
+    RETURN_IF_EXCEPTION(scope, {});
+    auto* str = stringValue.toString(lexicalGlobalObject);
+    uint32_t offset = offsetValue.toUInt32(lexicalGlobalObject);
+    RETURN_IF_EXCEPTION(scope, {});
+    uint32_t length = lengthValue.toUInt32(lexicalGlobalObject);
     RETURN_IF_EXCEPTION(scope, {});
-    if (userOffset < 0 || userOffset > max) {
-        throwNodeRangeError(lexicalGlobalObject, scope, "Offset is out of bounds"_s);
-        return {};
-    }
-    offset = static_cast<uint32_t>(userOffset);
-    uint32_t remaining = max - static_cast<uint32_t>(userOffset);
-
-    // https://github.com/nodejs/node/blob/e676942f814915b2d24fc899bb42dc71ae6c8226/lib/buffer.js#L1062-L1077
-    if (lengthValue.isUndefined()) {
-        length = remaining;
-    } else if (lengthValue.isString()) {
-        encodingValue = lengthValue;
-        setEncoding();
-        RETURN_IF_EXCEPTION(scope, {});
-        length = remaining;
-    } else {
-        setEncoding();
 
-        int32_t userLength = lengthValue.toInt32(lexicalGlobalObject);
-        RETURN_IF_EXCEPTION(scope, {});
-        length = std::min(static_cast<uint32_t>(userLength), remaining);
+    if (!encodingValue.toBoolean(lexicalGlobalObject)) {
+        RELEASE_AND_RETURN(scope, writeToBuffer(lexicalGlobalObject, castedThis, str, offset, length, WebCore::BufferEncodingType::utf8));
     }
 
+    auto encoding = parseEncoding(scope, lexicalGlobalObject, encodingValue, false);
+    RETURN_IF_EXCEPTION(scope, {});
+
     RELEASE_AND_RETURN(scope, writeToBuffer(lexicalGlobalObject, castedThis, str, offset, length, encoding));
 }
 
@@ -2210,7 +2247,6 @@ static const HashTableValue JSBufferPrototypeTableValues[]
           { "swap32"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsBufferPrototypeFunction_swap32, 0 } },
           { "swap64"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsBufferPrototypeFunction_swap64, 0 } },
           { "toJSON"_s, static_cast<unsigned>(JSC::PropertyAttribute::Builtin), NoIntrinsic, { HashTableValue::BuiltinGeneratorType, jsBufferPrototypeToJSONCodeGenerator, 1 } },
-          { "toLocaleString"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsBufferPrototypeFunction_toString, 4 } },
           { "toString"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsBufferPrototypeFunction_toString, 4 } },
           { "ucs2Slice"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsBufferPrototypeFunction_utf16leSlice, 2 } },
           { "ucs2Write"_s, static_cast<unsigned>(JSC::PropertyAttribute::Function), NoIntrinsic, { HashTableValue::NativeFunctionType, jsBufferPrototypeFunction_utf16leWrite, 3 } },
@@ -2262,6 +2298,8 @@ void JSBufferPrototype::finishCreation(VM& vm, JSC::JSGlobalObject* globalThis)
     JSC_TO_STRING_TAG_WITHOUT_TRANSITION();
     reifyStaticProperties(vm, JSBuffer::info(), JSBufferPrototypeTableValues, *this);
 
+    ALIAS("toLocaleString", "toString");
+
     ALIAS("readUintBE", "readUIntBE");
     ALIAS("readUintLE", "readUIntLE");
     ALIAS("readUint8", "readUInt8");
@@ -2339,6 +2377,128 @@ JSC::JSObject* createBufferConstructor(JSC::VM& vm, JSC::JSGlobalObject* globalO
 
 } // namespace WebCore
 
+JSC_DEFINE_HOST_FUNCTION(jsFunction_BufferFrom_Array, (JSGlobalObject * lexicalGlobalObject, CallFrame* callFrame))
+{
+    auto& vm = lexicalGlobalObject->vm();
+    auto throwScope = DECLARE_THROW_SCOPE(vm);
+
+    auto arrayValue = callFrame->argument(0);
+
+    return constructBufferFromArray(throwScope, lexicalGlobalObject, arrayValue);
+}
+EncodedJSValue constructBufferFromArray(JSC::ThrowScope& throwScope, JSGlobalObject* lexicalGlobalObject, JSValue arrayValue)
+{
+    auto* globalObject = reinterpret_cast<Zig::GlobalObject*>(lexicalGlobalObject);
+
+    auto* constructor = lexicalGlobalObject->m_typedArrayUint8.constructor(lexicalGlobalObject);
+    MarkedArgumentBuffer argsBuffer;
+    argsBuffer.append(arrayValue);
+    JSValue target = globalObject->JSBufferConstructor();
+    // TODO: I wish we could avoid this - it adds ~30ns of overhead just using JSC::construct.
+    auto* object = JSC::construct(lexicalGlobalObject, constructor, target, argsBuffer, "Buffer failed to construct"_s);
+    RETURN_IF_EXCEPTION(throwScope, {});
+    RELEASE_AND_RETURN(throwScope, JSC::JSValue::encode(object));
+}
+JSC_DEFINE_HOST_FUNCTION(jsFunction_BufferFrom_ArrayBuffer, (JSGlobalObject * lexicalGlobalObject, CallFrame* callFrame))
+{
+    auto& vm = lexicalGlobalObject->vm();
+    auto throwScope = DECLARE_THROW_SCOPE(vm);
+    auto argsCount = callFrame->argumentCount();
+
+    auto arrayBufferValue = callFrame->argument(0);
+    auto offsetValue = callFrame->argument(1);
+    auto lengthValue = callFrame->argument(2);
+
+    return constructBufferFromArrayBuffer(throwScope, lexicalGlobalObject, argsCount, arrayBufferValue, offsetValue, lengthValue);
+}
+EncodedJSValue constructBufferFromArrayBuffer(JSC::ThrowScope& throwScope, JSGlobalObject* lexicalGlobalObject, size_t argsCount, JSValue arrayBufferValue, JSValue offsetValue, JSValue lengthValue)
+{
+    auto* globalObject = reinterpret_cast<Zig::GlobalObject*>(lexicalGlobalObject);
+
+    auto* jsBuffer = jsCast<JSC::JSArrayBuffer*>(arrayBufferValue.asCell());
+    RefPtr<ArrayBuffer> buffer = jsBuffer->impl();
+    if (buffer->isDetached()) {
+        // TOOD: return Node.js error
+        throwTypeError(globalObject, throwScope, "Buffer is detached"_s);
+        return {};
+    }
+    size_t byteLength = buffer->byteLength();
+    double byteLengthD = byteLength;
+
+    // This closely matches `new Uint8Array(buffer, byteOffset, length)` in JavaScriptCore's implementation.
+    // See Source/JavaScriptCore/runtime/JSGenericTypedArrayViewConstructorInlines.h
+    size_t offset = 0;
+    std::optional<size_t> length;
+    size_t maxLength = byteLength;
+    if (argsCount > 1) {
+
+        if (!offsetValue.isUndefined()) {
+            offsetValue = jsDoubleNumber(offsetValue.toNumber(lexicalGlobalObject));
+            RETURN_IF_EXCEPTION(throwScope, {});
+            if (std::isnan(offsetValue.asNumber())) offsetValue = jsNumber(0);
+            if ((byteLengthD - offsetValue.asNumber()) < 0) return Bun::ERR::BUFFER_OUT_OF_BOUNDS(throwScope, lexicalGlobalObject, "offset"_s);
+            maxLength = byteLengthD - offsetValue.asNumber();
+            offset = offsetValue.asNumber();
+        }
+
+        if (!lengthValue.isUndefined()) {
+            lengthValue = jsDoubleNumber(lengthValue.toNumber(lexicalGlobalObject));
+            RETURN_IF_EXCEPTION(throwScope, {});
+            if (std::isnan(lengthValue.asNumber())) lengthValue = jsNumber(0);
+            length = lengthValue.asNumber();
+            if (length > 0) {
+                if (length > maxLength) {
+                    return Bun::ERR::BUFFER_OUT_OF_BOUNDS(throwScope, lexicalGlobalObject, "length"_s);
+                }
+            } else {
+                length = 0;
+            }
+        }
+    }
+
+    if (offset > byteLength) {
+        return Bun::ERR::BUFFER_OUT_OF_BOUNDS(throwScope, globalObject, "offset"_s);
+    }
+
+    if (!length) {
+        if (buffer->isResizableOrGrowableShared()) {
+            if (UNLIKELY(offset > byteLength)) {
+                return Bun::ERR::BUFFER_OUT_OF_BOUNDS(throwScope, globalObject, "byteOffset"_s);
+            }
+        } else {
+            length = (byteLength - offset);
+        }
+    }
+    if (offset + length.value() > byteLength) {
+        return Bun::ERR::BUFFER_OUT_OF_BOUNDS(throwScope, globalObject, "length"_s);
+    }
+
+    auto* subclassStructure = globalObject->JSBufferSubclassStructure();
+    auto* uint8Array = JSC::JSUint8Array::create(lexicalGlobalObject, subclassStructure, WTFMove(buffer), offset, length);
+    if (UNLIKELY(!uint8Array)) {
+        throwOutOfMemoryError(globalObject, throwScope);
+        return JSC::JSValue::encode({});
+    }
+
+    RELEASE_AND_RETURN(throwScope, JSC::JSValue::encode(uint8Array));
+}
+JSC_DEFINE_HOST_FUNCTION(jsFunction_BufferFrom_Size, (JSGlobalObject * lexicalGlobalObject, CallFrame* callFrame))
+{
+    auto& vm = lexicalGlobalObject->vm();
+    auto throwScope = DECLARE_THROW_SCOPE(vm);
+    auto lengthValue = callFrame->argument(0);
+    Bun::V::validateNumber(throwScope, lexicalGlobalObject, lengthValue, "size"_s, jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
+    RETURN_IF_EXCEPTION(throwScope, {});
+    size_t length = lengthValue.toLength(lexicalGlobalObject);
+    return JSBuffer__bufferFromLength(lexicalGlobalObject, length);
+}
+JSC_DEFINE_HOST_FUNCTION(jsFunction_BufferFrom_String, (JSGlobalObject * lexicalGlobalObject, CallFrame* callFrame))
+{
+    auto stringValue = callFrame->argument(0);
+    auto encodingValue = callFrame->argument(1);
+    return constructBufferFromStringAndEncoding(lexicalGlobalObject, stringValue, encodingValue);
+}
+
 static inline JSC::EncodedJSValue createJSBufferFromJS(JSC::JSGlobalObject* lexicalGlobalObject, JSValue newTarget, ArgList args)
 {
     VM& vm = lexicalGlobalObject->vm();
@@ -2359,7 +2519,7 @@ static inline JSC::EncodedJSValue createJSBufferFromJS(JSC::JSGlobalObject* lexi
         return JSBuffer__bufferFromLength(lexicalGlobalObject, distinguishingArg.asAnyInt());
     } else if (distinguishingArg.isNumber()) {
         JSValue lengthValue = distinguishingArg;
-        Bun::V::validateNumber(throwScope, lexicalGlobalObject, lengthValue, jsString(vm, String("size"_s)), jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
+        Bun::V::validateNumber(throwScope, lexicalGlobalObject, lengthValue, "size"_s, jsNumber(0), jsNumber(Bun::Buffer::kMaxLength));
         RETURN_IF_EXCEPTION(throwScope, {});
         size_t length = lengthValue.toLength(lexicalGlobalObject);
         return JSBuffer__bufferFromLength(lexicalGlobalObject, length);
@@ -2435,56 +2595,7 @@ static inline JSC::EncodedJSValue createJSBufferFromJS(JSC::JSGlobalObject* lexi
         case ArrayBufferType: {
             // This closely matches `new Uint8Array(buffer, byteOffset, length)` in JavaScriptCore's implementation.
             // See Source/JavaScriptCore/runtime/JSGenericTypedArrayViewConstructorInlines.h
-            size_t offset = 0;
-            std::optional<size_t> length;
-            if (argsCount > 1) {
-
-                offset = args.at(1).toTypedArrayIndex(globalObject, "byteOffset"_s);
-
-                // TOOD: return Node.js error
-                RETURN_IF_EXCEPTION(throwScope, {});
-
-                if (argsCount > 2) {
-                    // If the length value is present but undefined, treat it as missing.
-                    JSValue lengthValue = args.at(2);
-                    if (!lengthValue.isUndefined()) {
-                        length = lengthValue.toTypedArrayIndex(globalObject, "length"_s);
-
-                        // TOOD: return Node.js error
-                        RETURN_IF_EXCEPTION(throwScope, {});
-                    }
-                }
-            }
-
-            auto* jsBuffer = jsCast<JSC::JSArrayBuffer*>(distinguishingArg.asCell());
-            RefPtr<ArrayBuffer> buffer = jsBuffer->impl();
-            if (buffer->isDetached()) {
-                // TOOD: return Node.js error
-                throwTypeError(globalObject, throwScope, "Buffer is detached"_s);
-                return {};
-            }
-
-            if (!length) {
-                size_t byteLength = buffer->byteLength();
-                if (buffer->isResizableOrGrowableShared()) {
-                    if (UNLIKELY(offset > byteLength)) {
-                        // TOOD: return Node.js error
-                        throwNodeRangeError(globalObject, throwScope, "byteOffset exceeds source ArrayBuffer byteLength"_s);
-                        return {};
-                    }
-                } else {
-                    length = (byteLength - offset);
-                }
-            }
-
-            auto* subclassStructure = globalObject->JSBufferSubclassStructure();
-            auto* uint8Array = JSC::JSUint8Array::create(lexicalGlobalObject, subclassStructure, WTFMove(buffer), offset, length);
-            if (UNLIKELY(!uint8Array)) {
-                throwOutOfMemoryError(globalObject, throwScope);
-                return JSC::JSValue::encode({});
-            }
-
-            RELEASE_AND_RETURN(throwScope, JSC::JSValue::encode(uint8Array));
+            return constructBufferFromArrayBuffer(throwScope, lexicalGlobalObject, args.size(), distinguishingArg, args.at(1), args.at(2));
         }
         default: {
             break;
@@ -2492,24 +2603,7 @@ static inline JSC::EncodedJSValue createJSBufferFromJS(JSC::JSGlobalObject* lexi
         }
     }
 
-    JSC::JSObject* constructor = lexicalGlobalObject->m_typedArrayUint8.constructor(lexicalGlobalObject);
-
-    MarkedArgumentBuffer argsBuffer;
-    argsBuffer.append(distinguishingArg);
-    for (size_t i = 1; i < argsCount; ++i)
-        argsBuffer.append(args.at(i));
-
-    JSValue target = newTarget;
-    if (!target || !target.isCell()) {
-        target = globalObject->JSBufferConstructor();
-    }
-
-    JSC::JSObject* object = JSC::construct(lexicalGlobalObject, constructor, target, args, "Buffer failed to construct"_s);
-    if (!object) {
-        return JSC::JSValue::encode({});
-    }
-
-    RELEASE_AND_RETURN(throwScope, JSC::JSValue::encode(object));
+    return constructBufferFromArray(throwScope, lexicalGlobalObject, distinguishingArg);
 }
 
 JSC_DEFINE_HOST_FUNCTION(callJSBuffer, (JSC::JSGlobalObject * lexicalGlobalObject, JSC::CallFrame* callFrame))
diff --git a/src/bun.js/bindings/JSBuffer.h b/src/bun.js/bindings/JSBuffer.h
index 04795e6143a4b5..d23358c2868d5f 100644
--- a/src/bun.js/bindings/JSBuffer.h
+++ b/src/bun.js/bindings/JSBuffer.h
@@ -65,3 +65,11 @@ JSC::Structure* createBufferStructure(JSC::VM&, JSC::JSGlobalObject*, JSC::JSVal
 JSC::JSObject* createBufferConstructor(JSC::VM&, JSC::JSGlobalObject*, JSC::JSObject* bufferPrototype);
 
 }
+
+JSC_DEFINE_HOST_FUNCTION(jsFunction_BufferFrom_Array, (JSC::JSGlobalObject * lexicalGlobalObject, JSC::CallFrame* callFrame));
+JSC_DEFINE_HOST_FUNCTION(jsFunction_BufferFrom_ArrayBuffer, (JSC::JSGlobalObject * lexicalGlobalObject, JSC::CallFrame* callFrame));
+JSC_DEFINE_HOST_FUNCTION(jsFunction_BufferFrom_Size, (JSC::JSGlobalObject * lexicalGlobalObject, JSC::CallFrame* callFrame));
+JSC_DEFINE_HOST_FUNCTION(jsFunction_BufferFrom_String, (JSC::JSGlobalObject * lexicalGlobalObject, JSC::CallFrame* callFrame));
+
+JSC::EncodedJSValue constructBufferFromArrayBuffer(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* lexicalGlobalObject, size_t argsCount, JSC::JSValue arrayBufferValue, JSC::JSValue offsetValue, JSC::JSValue lengthValue);
+JSC::EncodedJSValue constructBufferFromArray(JSC::ThrowScope& throwScope, JSC::JSGlobalObject* lexicalGlobalObject, JSC::JSValue arrayValue);
diff --git a/src/bun.js/bindings/NodeValidator.cpp b/src/bun.js/bindings/NodeValidator.cpp
index c259609ef63aca..6ac04baba060b8 100644
--- a/src/bun.js/bindings/NodeValidator.cpp
+++ b/src/bun.js/bindings/NodeValidator.cpp
@@ -51,6 +51,24 @@ JSC::EncodedJSValue V::validateInteger(JSC::ThrowScope& scope, JSC::JSGlobalObje
 
     return JSValue::encode(jsUndefined());
 }
+JSC::EncodedJSValue V::validateInteger(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSC::JSValue value, const WTF::String& name, JSC::JSValue min, JSC::JSValue max)
+{
+    if (!value.isNumber()) return Bun::ERR::INVALID_ARG_TYPE(scope, globalObject, name, "number"_s, value);
+    if (min.isUndefined()) min = jsDoubleNumber(JSC::minSafeInteger());
+    if (max.isUndefined()) max = jsDoubleNumber(JSC::maxSafeInteger());
+
+    auto value_num = value.asNumber();
+    auto min_num = min.toNumber(globalObject);
+    RETURN_IF_EXCEPTION(scope, {});
+    auto max_num = max.toNumber(globalObject);
+    RETURN_IF_EXCEPTION(scope, {});
+    max_num = std::max(min_num, max_num);
+
+    if (std::fmod(value_num, 1.0) != 0) return Bun::ERR::OUT_OF_RANGE(scope, globalObject, name, "an integer"_s, value);
+    if (value_num < min_num || value_num > max_num) return Bun::ERR::OUT_OF_RANGE(scope, globalObject, name, min_num, max_num, value);
+
+    return JSValue::encode(jsUndefined());
+}
 
 JSC_DEFINE_HOST_FUNCTION(jsFunction_validateNumber, (JSC::JSGlobalObject * globalObject, JSC::CallFrame* callFrame))
 {
@@ -82,7 +100,27 @@ JSC::EncodedJSValue V::validateNumber(JSC::ThrowScope& scope, JSC::JSGlobalObjec
         if (max_isnonnull) return Bun::ERR::OUT_OF_RANGE(scope, globalObject, name, max_num, Bun::UPPER, value);
         return Bun::ERR::OUT_OF_RANGE(scope, globalObject, name, ""_s, value);
     }
+    return JSValue::encode(jsUndefined());
+}
+JSC::EncodedJSValue V::validateNumber(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue value, const WTF::String& name, JSValue min, JSValue max)
+{
+    if (!value.isNumber()) return Bun::ERR::INVALID_ARG_TYPE(scope, globalObject, name, "number"_s, value);
+
+    auto value_num = value.asNumber();
+    auto min_num = min.toNumber(globalObject);
+    RETURN_IF_EXCEPTION(scope, {});
+    auto max_num = max.toNumber(globalObject);
+    RETURN_IF_EXCEPTION(scope, {});
+
+    auto min_isnonnull = !min.isUndefinedOrNull();
+    auto max_isnonnull = !max.isUndefinedOrNull();
 
+    if ((min_isnonnull && value_num < min_num) || (max_isnonnull && value_num > max_num) || ((min_isnonnull || max_isnonnull) && std::isnan(value_num))) {
+        if (min_isnonnull && max_isnonnull) return Bun::ERR::OUT_OF_RANGE(scope, globalObject, name, min_num, max_num, value);
+        if (min_isnonnull) return Bun::ERR::OUT_OF_RANGE(scope, globalObject, name, min_num, Bun::LOWER, value);
+        if (max_isnonnull) return Bun::ERR::OUT_OF_RANGE(scope, globalObject, name, max_num, Bun::UPPER, value);
+        return Bun::ERR::OUT_OF_RANGE(scope, globalObject, name, ""_s, value);
+    }
     return JSValue::encode(jsUndefined());
 }
 
@@ -297,6 +335,30 @@ JSC_DEFINE_HOST_FUNCTION(jsFunction_validateArray, (JSC::JSGlobalObject * global
     auto value = callFrame->argument(0);
     auto name = callFrame->argument(1);
     auto minLength = callFrame->argument(2);
+    return V::validateArray(scope, globalObject, value, name, minLength);
+}
+JSC::EncodedJSValue V::validateArray(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue value, JSValue name, JSValue minLength)
+{
+    JSC::VM& vm = globalObject->vm();
+
+    if (minLength.isUndefined()) minLength = jsNumber(0);
+
+    if (!JSC::isArray(globalObject, value)) return Bun::ERR::INVALID_ARG_TYPE(scope, globalObject, name, "Array"_s, value);
+
+    auto length = value.get(globalObject, Identifier::fromString(vm, "length"_s));
+    RETURN_IF_EXCEPTION(scope, {});
+    auto length_num = length.toNumber(globalObject);
+    RETURN_IF_EXCEPTION(scope, {});
+    auto minLength_num = minLength.toNumber(globalObject);
+    RETURN_IF_EXCEPTION(scope, {});
+    if (length_num < minLength_num) {
+        return Bun::ERR::INVALID_ARG_VALUE(scope, globalObject, name, value, makeString("must be longer than "_s, minLength_num));
+    }
+    return JSValue::encode(jsUndefined());
+}
+JSC::EncodedJSValue V::validateArray(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue value, const WTF::String& name, JSValue minLength)
+{
+    JSC::VM& vm = globalObject->vm();
 
     if (minLength.isUndefined()) minLength = jsNumber(0);
 
@@ -454,6 +516,12 @@ JSC_DEFINE_HOST_FUNCTION(jsFunction_validateBuffer, (JSC::JSGlobalObject * globa
 
     auto buffer = callFrame->argument(0);
     auto name = callFrame->argument(1);
+    return V::validateBuffer(scope, globalObject, buffer, name);
+}
+JSC::EncodedJSValue V::validateBuffer(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue buffer, JSValue nameValue)
+{
+    auto name = nameValue.isUndefined() ? "buffer"_s : nameValue.toWTFString(globalObject);
+    RETURN_IF_EXCEPTION(scope, {});
 
     if (!buffer.isCell()) return JSValue::encode(jsUndefined());
     auto ty = buffer.asCell()->type();
diff --git a/src/bun.js/bindings/NodeValidator.h b/src/bun.js/bindings/NodeValidator.h
index b691c7f5e0dc6a..1a32502a7c4e7e 100644
--- a/src/bun.js/bindings/NodeValidator.h
+++ b/src/bun.js/bindings/NodeValidator.h
@@ -26,11 +26,16 @@ JSC_DEFINE_HOST_FUNCTION(jsFunction_validateBuffer, (JSC::JSGlobalObject * globa
 
 namespace V {
 
+JSC::EncodedJSValue validateInteger(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSC::JSValue value, const WTF::String& name, JSC::JSValue min, JSC::JSValue max);
 JSC::EncodedJSValue validateInteger(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSC::JSValue value, JSC::JSValue name, JSC::JSValue min, JSC::JSValue max);
 JSC::EncodedJSValue validateNumber(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSC::JSValue value, JSC::JSValue name, JSC::JSValue min, JSC::JSValue max);
+JSC::EncodedJSValue validateNumber(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue value, const WTF::String& name, JSValue min, JSValue max);
 JSC::EncodedJSValue validateFiniteNumber(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSC::JSValue number, JSC::JSValue name);
 JSC::EncodedJSValue validateString(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue value, JSValue name);
 JSC::EncodedJSValue validateString(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue value, ASCIILiteral name);
+JSC::EncodedJSValue validateArray(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue value, JSValue name, JSValue minLength);
+JSC::EncodedJSValue validateArray(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue value, const WTF::String& name, JSValue minLength);
+JSC::EncodedJSValue validateBuffer(JSC::ThrowScope& scope, JSC::JSGlobalObject* globalObject, JSValue buffer, JSValue name);
 
 }
 
diff --git a/src/bun.js/bindings/bindings.zig b/src/bun.js/bindings/bindings.zig
index e79bf9799f4265..00ea18daa04c23 100644
--- a/src/bun.js/bindings/bindings.zig
+++ b/src/bun.js/bindings/bindings.zig
@@ -654,7 +654,7 @@ pub const ZigString = extern struct {
         return (@intFromPtr(this._unsafe_ptr_do_not_use) & (1 << 63)) != 0;
     }
 
-    pub inline fn utf16Slice(this: *const ZigString) []align(1) const u16 {
+    pub fn utf16Slice(this: *const ZigString) []align(1) const u16 {
         if (comptime bun.Environment.allow_assert) {
             if (this.len > 0 and !this.is16Bit()) {
                 @panic("ZigString.utf16Slice() called on a latin1 string.\nPlease use .toSlice() instead or carefully check that .is16Bit() is false first.");
@@ -664,7 +664,7 @@ pub const ZigString = extern struct {
         return @as([*]align(1) const u16, @ptrCast(untagged(this._unsafe_ptr_do_not_use)))[0..this.len];
     }
 
-    pub inline fn utf16SliceAligned(this: *const ZigString) []const u16 {
+    pub fn utf16SliceAligned(this: *const ZigString) []const u16 {
         if (comptime bun.Environment.allow_assert) {
             if (this.len > 0 and !this.is16Bit()) {
                 @panic("ZigString.utf16SliceAligned() called on a latin1 string.\nPlease use .toSlice() instead or carefully check that .is16Bit() is false first.");
diff --git a/src/bun.js/node/buffer.zig b/src/bun.js/node/buffer.zig
index 86d4fc73c1e907..af51604049fa63 100644
--- a/src/bun.js/node/buffer.zig
+++ b/src/bun.js/node/buffer.zig
@@ -49,6 +49,8 @@ pub const BufferVectorized = struct {
                 Encoder.writeU8(str.slice().ptr, str.slice().len, buf.ptr, buf.len, .hex),
         } catch return false;
 
+        if (written == 0 and str.length() > 0) return false;
+
         switch (written) {
             0 => return true,
             1 => {
diff --git a/src/bun.js/webcore/encoding.zig b/src/bun.js/webcore/encoding.zig
index f50424ea35bc9a..57aa62e1229062 100644
--- a/src/bun.js/webcore/encoding.zig
+++ b/src/bun.js/webcore/encoding.zig
@@ -1335,7 +1335,7 @@ pub const Encoder = struct {
             },
 
             .hex => {
-                return strings.decodeHexToBytes(to_ptr[0..to_len], u8, input[0..len]);
+                return strings.decodeHexToBytesTruncate(to_ptr[0..to_len], u8, input[0..len]);
             },
 
             .base64, .base64url => {
@@ -1414,7 +1414,7 @@ pub const Encoder = struct {
             },
 
             .hex => {
-                return strings.decodeHexToBytes(to[0..to_len], u16, input[0..len]);
+                return strings.decodeHexToBytesTruncate(to[0..to_len], u16, input[0..len]);
             },
 
             .base64, .base64url => {
diff --git a/src/cli.zig b/src/cli.zig
index 95c5a10a047b93..3e9c3cf926c56d 100644
--- a/src/cli.zig
+++ b/src/cli.zig
@@ -47,6 +47,8 @@ pub var start_time: i128 = undefined;
 const Bunfig = @import("./bunfig.zig").Bunfig;
 const OOM = bun.OOM;
 
+export var Bun__Node__ZeroFillBuffers = false;
+
 pub const Cli = struct {
     pub const CompileTarget = @import("./compile_target.zig");
     var wait_group: sync.WaitGroup = undefined;
@@ -232,6 +234,7 @@ pub const Arguments = struct {
         clap.parseParam("--fetch-preconnect <STR>...       Preconnect to a URL while code is loading") catch unreachable,
         clap.parseParam("--max-http-header-size <INT>      Set the maximum size of HTTP headers in bytes. Default is 16KiB") catch unreachable,
         clap.parseParam("--expose-internals                Expose internals used for testing Bun itself. Usage of these APIs are completely unsupported.") catch unreachable,
+        clap.parseParam("--zero-fill-buffers               Boolean to force Buffer.allocUnsafe(size) to be zero-filled.") catch unreachable,
     };
 
     const auto_or_run_params = [_]ParamType{
@@ -794,6 +797,9 @@ pub const Arguments = struct {
             if (args.flag("--expose-internals")) {
                 bun.JSC.ModuleLoader.is_allowed_to_use_internal_testing_apis = true;
             }
+            if (args.flag("--zero-fill-buffers")) {
+                Bun__Node__ZeroFillBuffers = true;
+            }
         }
 
         if (opts.port != null and opts.origin == null) {
diff --git a/src/js/builtins.d.ts b/src/js/builtins.d.ts
index 2c07c8aa0e350d..ce852739c0dd62 100644
--- a/src/js/builtins.d.ts
+++ b/src/js/builtins.d.ts
@@ -537,7 +537,11 @@ declare interface Function {
 }
 
 declare var $Buffer: {
-  new (a: any, b?: any, c?: any): Buffer;
+  new (array: Array): Buffer;
+  new (arrayBuffer: ArrayBuffer, byteOffset?: number, length?: number): Buffer;
+  new (buffer: Buffer): Buffer;
+  new (size: number): Buffer;
+  new (string: string, encoding?: BufferEncoding): Buffer;
 };
 
 declare interface Error {
diff --git a/src/js/builtins/JSBufferConstructor.ts b/src/js/builtins/JSBufferConstructor.ts
index 2c0c09e982ba7f..ace7afd5332441 100644
--- a/src/js/builtins/JSBufferConstructor.ts
+++ b/src/js/builtins/JSBufferConstructor.ts
@@ -1,78 +1,37 @@
 // This is marked as a constructor because Node.js allows `new Buffer.from`,
 // Some legacy dependencies depend on this, see #3638
 $constructor;
-export function from(items) {
-  if ($isUndefinedOrNull(items)) {
-    throw new TypeError(
-      "The first argument must be one of type string, Buffer, ArrayBuffer, Array, or Array-like Object.",
-    );
-  }
+export function from(value, encodingOrOffset, length) {
+  const { fromString, fromArrayBuffer, fromObject } = require("internal/buffer");
+  const { isAnyArrayBuffer } = require("node:util/types");
 
-  // TODO: figure out why private symbol not found
-  if (
-    typeof items === "string" ||
-    (typeof items === "object" &&
-      ($isTypedArrayView(items) ||
-        items instanceof ArrayBuffer ||
-        items instanceof SharedArrayBuffer ||
-        items instanceof String))
-  ) {
-    switch ($argumentCount()) {
-      case 1: {
-        return new $Buffer(items);
-      }
-      case 2: {
-        return new $Buffer(items, $argument(1));
-      }
-      default: {
-        return new $Buffer(items, $argument(1), $argument(2));
-      }
-    }
-  }
-  if (typeof items === "object") {
-    const data = items.data;
-    if (items.type === "Buffer" && Array.isArray(data)) {
-      return new $Buffer(data);
-    }
-  }
+  if (typeof value === "string") return fromString(value, encodingOrOffset);
 
-  var arrayLike = $toObject(
-    items,
-    "The first argument must be of type string or an instance of Buffer, ArrayBuffer, or Array or an Array-like Object.",
-  ) as ArrayLike<any>;
+  if (typeof value === "object" && value !== null) {
+    if (isAnyArrayBuffer(value)) return fromArrayBuffer(value, encodingOrOffset, length);
 
-  if (!$isJSArray(arrayLike)) {
-    const toPrimitive = $tryGetByIdWithWellKnownSymbol(items, "toPrimitive");
+    const valueOf = value.valueOf && value.valueOf();
+    if (valueOf != null && valueOf !== value && (typeof valueOf === "string" || typeof valueOf === "object")) {
+      return Buffer.from(valueOf, encodingOrOffset, length);
+    }
 
-    if (toPrimitive) {
-      const primitive = toPrimitive.$call(items, "string");
+    const b = fromObject(value);
+    if (b) return b;
 
+    const toPrimitive = $tryGetByIdWithWellKnownSymbol(value, "toPrimitive");
+    if (typeof toPrimitive === "function") {
+      const primitive = toPrimitive.$call(value, "string");
       if (typeof primitive === "string") {
-        switch ($argumentCount()) {
-          case 1: {
-            return new $Buffer(primitive);
-          }
-          case 2: {
-            return new $Buffer(primitive, $argument(1));
-          }
-          default: {
-            return new $Buffer(primitive, $argument(1), $argument(2));
-          }
-        }
+        return fromString(primitive, encodingOrOffset);
       }
     }
-
-    if (!("length" in arrayLike) || $isCallable(arrayLike)) {
-      throw new TypeError(
-        "The first argument must be of type string or an instance of Buffer, ArrayBuffer, or Array or an Array-like Object.",
-      );
-    }
   }
 
-  // Don't pass the second argument because Node's Buffer.from doesn't accept
-  // a function and Uint8Array.from requires it if it exists
-  // That means we cannot use $tailCallFowrardArguments here, sadly
-  return new $Buffer(Uint8Array.from(arrayLike).buffer);
+  throw $ERR_INVALID_ARG_TYPE(
+    "first argument",
+    ["string", "Buffer", "ArrayBuffer", "Array", "Array-like Object"],
+    value,
+  );
 }
 
 export function isBuffer(bufferlike) {
diff --git a/src/js/builtins/JSBufferPrototype.ts b/src/js/builtins/JSBufferPrototype.ts
index 99ca59405aa5ac..fcb02ea859ac00 100644
--- a/src/js/builtins/JSBufferPrototype.ts
+++ b/src/js/builtins/JSBufferPrototype.ts
@@ -8,46 +8,93 @@ interface BufferExt extends Buffer {
   toString(offset: number, length: number, encoding?: BufferEncoding): string;
 }
 
-export function setBigUint64(this: BufferExt, offset, value, le) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigUint64(
-    offset,
-    value,
-    le,
-  );
-}
 export function readInt8(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt8(offset);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 1);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getInt8(offset);
 }
+
 export function readUInt8(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint8(offset);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 1);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getUint8(offset);
 }
+
 export function readInt16LE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt16(offset, true);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 2);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getInt16(offset, true);
 }
+
 export function readInt16BE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt16(offset, false);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 2);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getInt16(offset, false);
 }
+
 export function readUInt16LE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint16(offset, true);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 2);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getUint16(offset, true);
 }
+
 export function readUInt16BE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint16(offset, false);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 2);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getUint16(offset, false);
 }
+
 export function readInt32LE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt32(offset, true);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 4);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getInt32(offset, true);
 }
+
 export function readInt32BE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getInt32(offset, false);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 4);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getInt32(offset, false);
 }
+
 export function readUInt32LE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint32(offset, true);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 4);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getUint32(offset, true);
 }
+
 export function readUInt32BE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getUint32(offset, false);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 4);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getUint32(offset, false);
 }
 
 export function readIntLE(this: BufferExt, offset, byteLength) {
+  const { ERR_INVALID_ARG_TYPE, validateInteger, boundsError } = require("internal/buffer");
+  if (offset === undefined) throw ERR_INVALID_ARG_TYPE("offset", "number", offset);
+
   const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+
+  switch (byteLength) {
+    case 1:
+    case 2:
+    case 3:
+    case 4:
+    case 5:
+    case 6:
+      validateInteger(offset, "offset");
+      if (!(offset >= 0 && offset <= this.length - byteLength)) boundsError(offset, this.length - byteLength);
+      break;
+  }
   switch (byteLength) {
     case 1: {
       return view.getInt8(offset);
@@ -71,10 +118,26 @@ export function readIntLE(this: BufferExt, offset, byteLength) {
       return (last | ((last & (2 ** 15)) * 0x1fffe)) * 2 ** 32 + view.getUint32(offset, true);
     }
   }
-  throw new RangeError("byteLength must be >= 1 and <= 6");
+  boundsError(byteLength, 6, "byteLength");
 }
+
 export function readIntBE(this: BufferExt, offset, byteLength) {
+  const { ERR_INVALID_ARG_TYPE, validateInteger, boundsError } = require("internal/buffer");
+  if (offset === undefined) throw ERR_INVALID_ARG_TYPE("offset", "number", offset);
+
   const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+
+  switch (byteLength) {
+    case 1:
+    case 2:
+    case 3:
+    case 4:
+    case 5:
+    case 6:
+      validateInteger(offset, "offset");
+      if (!(offset >= 0 && offset <= this.length - byteLength)) boundsError(offset, this.length - byteLength);
+      break;
+  }
   switch (byteLength) {
     case 1: {
       return view.getInt8(offset);
@@ -98,10 +161,26 @@ export function readIntBE(this: BufferExt, offset, byteLength) {
       return (last | ((last & (2 ** 15)) * 0x1fffe)) * 2 ** 32 + view.getUint32(offset + 2, false);
     }
   }
-  throw new RangeError("byteLength must be >= 1 and <= 6");
+  boundsError(byteLength, 6, "byteLength");
 }
+
 export function readUIntLE(this: BufferExt, offset, byteLength) {
+  const { ERR_INVALID_ARG_TYPE, validateInteger, boundsError } = require("internal/buffer");
+  if (offset === undefined) throw ERR_INVALID_ARG_TYPE("offset", "number", offset);
+
   const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+
+  switch (byteLength) {
+    case 1:
+    case 2:
+    case 3:
+    case 4:
+    case 5:
+    case 6:
+      validateInteger(offset, "offset");
+      if (!(offset >= 0 && offset <= this.length - byteLength)) boundsError(offset, this.length - byteLength);
+      break;
+  }
   switch (byteLength) {
     case 1: {
       return view.getUint8(offset);
@@ -122,10 +201,26 @@ export function readUIntLE(this: BufferExt, offset, byteLength) {
       return view.getUint16(offset + 4, true) * 2 ** 32 + view.getUint32(offset, true);
     }
   }
-  throw new RangeError("byteLength must be >= 1 and <= 6");
+  boundsError(byteLength, 6, "byteLength");
 }
+
 export function readUIntBE(this: BufferExt, offset, byteLength) {
+  const { ERR_INVALID_ARG_TYPE, validateInteger, boundsError } = require("internal/buffer");
+  if (offset === undefined) throw ERR_INVALID_ARG_TYPE("offset", "number", offset);
+
   const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+
+  switch (byteLength) {
+    case 1:
+    case 2:
+    case 3:
+    case 4:
+    case 5:
+    case 6:
+      validateInteger(offset, "offset");
+      if (!(offset >= 0 && offset <= this.length - byteLength)) boundsError(offset, this.length - byteLength);
+      break;
+  }
   switch (byteLength) {
     case 1: {
       return view.getUint8(offset);
@@ -146,331 +241,404 @@ export function readUIntBE(this: BufferExt, offset, byteLength) {
       return view.getUint16(offset, false) * 2 ** 32 + view.getUint32(offset + 2, false);
     }
   }
-  throw new RangeError("byteLength must be >= 1 and <= 6");
+  boundsError(byteLength, 6, "byteLength");
 }
 
 export function readFloatLE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getFloat32(offset, true);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 4);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getFloat32(offset, true);
 }
+
 export function readFloatBE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getFloat32(offset, false);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 4);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getFloat32(offset, false);
 }
+
 export function readDoubleLE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getFloat64(offset, true);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 8);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getFloat64(offset, true);
 }
+
 export function readDoubleBE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getFloat64(offset, false);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 8);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getFloat64(offset, false);
 }
+
 export function readBigInt64LE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getBigInt64(offset, true);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 8);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getBigInt64(offset, true);
 }
+
 export function readBigInt64BE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getBigInt64(offset, false);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 8);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getBigInt64(offset, false);
 }
+
 export function readBigUInt64LE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getBigUint64(offset, true);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 8);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getBigUint64(offset, true);
 }
+
 export function readBigUInt64BE(this: BufferExt, offset) {
-  return (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).getBigUint64(offset, false);
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_read(this, offset, 8);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  return view.getBigUint64(offset, false);
 }
 
 export function writeInt8(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt8(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int8(this, value, offset, -0x80, 0x7f);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setInt8(offset, value);
   return offset + 1;
 }
+
 export function writeUInt8(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint8(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int8(this, value, offset, 0, 0xff);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setUint8(offset, value);
   return offset + 1;
 }
+
 export function writeInt16LE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt16(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    true,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int16(this, value, offset, -0x8000, 0x7fff);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setInt16(offset, value, true);
   return offset + 2;
 }
+
 export function writeInt16BE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt16(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    false,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int16(this, value, offset, -0x8000, 0x7fff);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setInt16(offset, value, false);
   return offset + 2;
 }
+
 export function writeUInt16LE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint16(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    true,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int16(this, value, offset, 0, 0xffff);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setUint16(offset, value, true);
   return offset + 2;
 }
+
 export function writeUInt16BE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint16(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    false,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int16(this, value, offset, 0, 0xffff);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setUint16(offset, value, false);
   return offset + 2;
 }
+
 export function writeInt32LE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt32(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    true,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int32(this, value, offset, -0x80000000, 0x7fffffff);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setInt32(offset, value, true);
   return offset + 4;
 }
+
 export function writeInt32BE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setInt32(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    false,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int32(this, value, offset, -0x80000000, 0x7fffffff);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setInt32(offset, value, false);
   return offset + 4;
 }
+
 export function writeUInt32LE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint32(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    true,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int32(this, value, offset, 0, 0xffffffff);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setUint32(offset, value, true);
   return offset + 4;
 }
+
 export function writeUInt32BE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setUint32(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    false,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").check_int32(this, value, offset, 0, 0xffffffff);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setUint32(offset, value, false);
   return offset + 4;
 }
 
 export function writeIntLE(this: BufferExt, value, offset, byteLength) {
   const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  value = +value;
 
   switch (byteLength) {
     case 1: {
+      require("internal/buffer").check_int8(this, value, offset, -0x80, 0x7f);
       view.setInt8(offset, value);
       break;
     }
     case 2: {
+      require("internal/buffer").check_int16(this, value, offset, -0x8000, 0x7fff);
       view.setInt16(offset, value, true);
       break;
     }
     case 3: {
+      require("internal/buffer").check_int24(this, value, offset, -0x800000, 0x7fffff);
       view.setUint16(offset, value & 0xffff, true);
       view.setInt8(offset + 2, Math.floor(value * 2 ** -16));
       break;
     }
     case 4: {
+      require("internal/buffer").check_int32(this, value, offset, -0x80000000, 0x7fffffff);
       view.setInt32(offset, value, true);
       break;
     }
     case 5: {
+      require("internal/buffer").check_int40(this, value, offset, -0x8000000000, 0x7fffffffff);
       view.setUint32(offset, value | 0, true);
       view.setInt8(offset + 4, Math.floor(value * 2 ** -32));
       break;
     }
     case 6: {
+      require("internal/buffer").check_int48(this, value, offset, -0x800000000000, 0x7fffffffffff);
       view.setUint32(offset, value | 0, true);
       view.setInt16(offset + 4, Math.floor(value * 2 ** -32), true);
       break;
     }
     default: {
-      throw new RangeError("byteLength must be >= 1 and <= 6");
+      require("internal/buffer").boundsError(byteLength, 6, "byteLength");
     }
   }
   return offset + byteLength;
 }
+
 export function writeIntBE(this: BufferExt, value, offset, byteLength) {
   const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  value = +value;
 
   switch (byteLength) {
     case 1: {
+      require("internal/buffer").check_int8(this, value, offset, -0x80, 0x7f);
       view.setInt8(offset, value);
       break;
     }
     case 2: {
+      require("internal/buffer").check_int16(this, value, offset, -0x8000, 0x7fff);
       view.setInt16(offset, value, false);
       break;
     }
     case 3: {
+      require("internal/buffer").check_int24(this, value, offset, -0x800000, 0x7fffff);
       view.setUint16(offset + 1, value & 0xffff, false);
       view.setInt8(offset, Math.floor(value * 2 ** -16));
       break;
     }
     case 4: {
+      require("internal/buffer").check_int32(this, value, offset, -0x80000000, 0x7fffffff);
       view.setInt32(offset, value, false);
       break;
     }
     case 5: {
+      require("internal/buffer").check_int40(this, value, offset, -0x8000000000, 0x7fffffffff);
       view.setUint32(offset + 1, value | 0, false);
       view.setInt8(offset, Math.floor(value * 2 ** -32));
       break;
     }
     case 6: {
+      require("internal/buffer").check_int48(this, value, offset, -0x800000000000, 0x7fffffffffff);
       view.setUint32(offset + 2, value | 0, false);
       view.setInt16(offset, Math.floor(value * 2 ** -32), false);
       break;
     }
     default: {
-      throw new RangeError("byteLength must be >= 1 and <= 6");
+      require("internal/buffer").boundsError(byteLength, 6, "byteLength");
     }
   }
   return offset + byteLength;
 }
+
 export function writeUIntLE(this: BufferExt, value, offset, byteLength) {
   const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  value = +value;
 
   switch (byteLength) {
     case 1: {
+      require("internal/buffer").check_int8(this, value, offset, 0, 0xff);
       view.setUint8(offset, value);
       break;
     }
     case 2: {
+      require("internal/buffer").check_int16(this, value, offset, 0, 0xffff);
       view.setUint16(offset, value, true);
       break;
     }
     case 3: {
+      require("internal/buffer").check_int24(this, value, offset, 0, 0xffffff);
       view.setUint16(offset, value & 0xffff, true);
       view.setUint8(offset + 2, Math.floor(value * 2 ** -16));
       break;
     }
     case 4: {
+      require("internal/buffer").check_int32(this, value, offset, 0, 0xffffffff);
       view.setUint32(offset, value, true);
       break;
     }
     case 5: {
+      require("internal/buffer").check_int40(this, value, offset, 0, 0xffffffffff);
       view.setUint32(offset, value | 0, true);
       view.setUint8(offset + 4, Math.floor(value * 2 ** -32));
       break;
     }
     case 6: {
+      require("internal/buffer").check_int48(this, value, offset, 0, 0xffffffffffff);
       view.setUint32(offset, value | 0, true);
       view.setUint16(offset + 4, Math.floor(value * 2 ** -32), true);
       break;
     }
     default: {
-      throw new RangeError("byteLength must be >= 1 and <= 6");
+      require("internal/buffer").boundsError(byteLength, 6, "byteLength");
     }
   }
   return offset + byteLength;
 }
+
 export function writeUIntBE(this: BufferExt, value, offset, byteLength) {
   const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  value = +value;
 
   switch (byteLength) {
     case 1: {
+      require("internal/buffer").check_int8(this, value, offset, 0, 0xff);
       view.setUint8(offset, value);
       break;
     }
     case 2: {
+      require("internal/buffer").check_int16(this, value, offset, 0, 0xffff);
       view.setUint16(offset, value, false);
       break;
     }
     case 3: {
+      require("internal/buffer").check_int24(this, value, offset, 0, 0xffffff);
       view.setUint16(offset + 1, value & 0xffff, false);
       view.setUint8(offset, Math.floor(value * 2 ** -16));
       break;
     }
     case 4: {
+      require("internal/buffer").check_int32(this, value, offset, 0, 0xffffffff);
       view.setUint32(offset, value, false);
       break;
     }
     case 5: {
+      require("internal/buffer").check_int40(this, value, offset, 0, 0xffffffffff);
       view.setUint32(offset + 1, value | 0, false);
       view.setUint8(offset, Math.floor(value * 2 ** -32));
       break;
     }
     case 6: {
+      require("internal/buffer").check_int48(this, value, offset, 0, 0xffffffffffff);
       view.setUint32(offset + 2, value | 0, false);
       view.setUint16(offset, Math.floor(value * 2 ** -32), false);
       break;
     }
     default: {
-      throw new RangeError("byteLength must be >= 1 and <= 6");
+      require("internal/buffer").boundsError(byteLength, 6, "byteLength");
     }
   }
   return offset + byteLength;
 }
 
 export function writeFloatLE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setFloat32(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    true,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").checkBounds(this, offset, 3);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setFloat32(offset, value, true);
   return offset + 4;
 }
 
 export function writeFloatBE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setFloat32(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    false,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").checkBounds(this, offset, 3);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setFloat32(offset, value, false);
   return offset + 4;
 }
 
 export function writeDoubleLE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setFloat64(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    true,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").checkBounds(this, offset, 7);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setFloat64(offset, value, true);
   return offset + 8;
 }
 
 export function writeDoubleBE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setFloat64(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    false,
-  );
+  if (offset === undefined) offset = 0;
+  value = +value;
+  require("internal/buffer").checkBounds(this, offset, 7);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setFloat64(offset, value, false);
   return offset + 8;
 }
 
 export function writeBigInt64LE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigInt64(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    true,
-  );
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_bigint64(this, value, offset, -0x8000000000000000n, 0x7fffffffffffffffn);
+  if (typeof value !== "bigint") throw require("internal/buffer").ERR_INVALID_ARG_TYPE("value", "bigint", value);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setBigInt64(offset, value, true);
   return offset + 8;
 }
 
 export function writeBigInt64BE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigInt64(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    false,
-  );
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_bigint64(this, value, offset, -0x8000000000000000n, 0x7fffffffffffffffn);
+  if (typeof value !== "bigint") throw require("internal/buffer").ERR_INVALID_ARG_TYPE("value", "bigint", value);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setBigInt64(offset, value, false);
   return offset + 8;
 }
 
 export function writeBigUInt64LE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigUint64(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    true,
-  );
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_bigint64(this, value, offset, 0n, 0xffffffffffffffffn);
+  if (typeof value !== "bigint") throw require("internal/buffer").ERR_INVALID_ARG_TYPE("value", "bigint", value);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setBigUint64(offset, value, true);
   return offset + 8;
 }
 
 export function writeBigUInt64BE(this: BufferExt, value, offset) {
-  (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength)).setBigUint64(
-    offset === undefined ? (offset = 0) : offset,
-    value,
-    false,
-  );
+  if (offset === undefined) offset = 0;
+  require("internal/buffer").check_bigint64(this, value, offset, 0n, 0xffffffffffffffffn);
+  if (typeof value !== "bigint") throw require("internal/buffer").ERR_INVALID_ARG_TYPE("value", "bigint", value);
+  const view = (this.$dataView ||= new DataView(this.buffer, this.byteOffset, this.byteLength));
+  view.setBigUint64(offset, value, false);
   return offset + 8;
 }
 
@@ -487,7 +655,7 @@ export function slice(this: BufferExt, start, end) {
     // Use Math.trunc() to convert offset to an integer value that can be larger
     // than an Int32. Hence, don't use offset | 0 or similar techniques.
     offset = Math.trunc(offset);
-    if (offset === 0 || offset !== offset) {
+    if (offset === undefined || offset !== offset) {
       return 0;
     } else if (offset < 0) {
       offset += length;
diff --git a/src/js/internal/buffer.ts b/src/js/internal/buffer.ts
new file mode 100644
index 00000000000000..c03828d89c28c6
--- /dev/null
+++ b/src/js/internal/buffer.ts
@@ -0,0 +1,134 @@
+// XXX: should more of this file be c++ imports?
+const { validateNumber, validateInteger } = require("internal/validators");
+const { ERR_INVALID_ARG_TYPE, ERR_OUT_OF_RANGE, ERR_BUFFER_OUT_OF_BOUNDS } = require("internal/errors");
+const { isAnyArrayBuffer } = require("node:util/types");
+
+const BufferFrom1 = $newCppFunction("JSBuffer.cpp", "jsFunction_BufferFrom_Array", 0);
+const BufferFrom2 = $newCppFunction("JSBuffer.cpp", "jsFunction_BufferFrom_ArrayBuffer", 0);
+const BufferFrom4 = $newCppFunction("JSBuffer.cpp", "jsFunction_BufferFrom_Size", 0);
+const BufferFrom5 = $newCppFunction("JSBuffer.cpp", "jsFunction_BufferFrom_String", 0);
+
+const ArrayIsArray = Array.isArray;
+
+function boundsError(value, length, type?) {
+  if (Math.floor(value) !== value) {
+    validateNumber(value, type);
+    throw ERR_OUT_OF_RANGE(type || "offset", "an integer", value);
+  }
+  if (length < 0) throw ERR_BUFFER_OUT_OF_BOUNDS();
+  throw ERR_OUT_OF_RANGE(type || "offset", `>= ${type ? 1 : 0} and <= ${length}`, value);
+}
+
+function checkBounds(buf, offset, byteLength) {
+  validateNumber(offset, "offset");
+  if (buf[offset] === undefined || buf[offset + byteLength] === undefined)
+    boundsError(offset, buf.length - (byteLength + 1));
+}
+
+function checkInt(value, min, max, buf, offset, byteLength) {
+  if (value > max || value < min) {
+    const n = typeof min === "bigint" ? "n" : "";
+    let range;
+    if (byteLength > 3) {
+      if (min === 0 || min === 0n) {
+        range = `>= 0${n} and < 2${n} ** ${(byteLength + 1) * 8}${n}`;
+      } else {
+        range = `>= -(2${n} ** ${(byteLength + 1) * 8 - 1}${n}) and ` + `< 2${n} ** ${(byteLength + 1) * 8 - 1}${n}`;
+      }
+    } else {
+      range = `>= ${min}${n} and <= ${max}${n}`;
+    }
+    throw ERR_OUT_OF_RANGE("value", range, value);
+  }
+  checkBounds(buf, offset, byteLength);
+}
+
+function check_read(buf, offset, byteLength) {
+  validateInteger(offset, "offset");
+  const type = buf.length - byteLength;
+  if (!(offset >= 0 && offset <= type)) boundsError(offset, type);
+}
+
+function check_int8(buf, value, offset, min, max) {
+  validateNumber(offset, "offset");
+  if (value > max || value < min) throw ERR_OUT_OF_RANGE("value", `>= ${min} and <= ${max}`, value);
+  if (buf[offset] === undefined) boundsError(offset, buf.length - 1);
+}
+
+function check_int16(buf, value, offset, min, max) {
+  checkInt(value, min, max, buf, offset, 1);
+}
+
+function check_int24(buf, value, offset, min, max) {
+  checkInt(value, min, max, buf, offset, 2);
+}
+
+function check_int32(buf, value, offset, min, max) {
+  checkInt(value, min, max, buf, offset, 3);
+}
+
+function check_int40(buf, value, offset, min, max) {
+  checkInt(value, min, max, buf, offset, 4);
+}
+
+function check_int48(buf, value, offset, min, max) {
+  checkInt(value, min, max, buf, offset, 5);
+}
+
+function check_bigint64(buf, value, offset, min, max) {
+  checkInt(value, min, max, buf, offset, 7);
+}
+
+function fromString(string, encoding) {
+  return BufferFrom5(string, encoding);
+}
+
+function fromArrayBuffer(arrayBuffer: ArrayBuffer, byteOffset?: number, length?: number) {
+  return BufferFrom2(arrayBuffer, byteOffset, length);
+}
+
+function fromObject(obj) {
+  if (obj.length !== undefined || isAnyArrayBuffer(obj.buffer)) {
+    if (typeof obj.length !== "number") {
+      return BufferFrom4(0);
+    }
+    return fromArrayLike(obj);
+  }
+  if (obj.type === "Buffer" && ArrayIsArray(obj.data)) {
+    return fromArrayLike(obj.data);
+  }
+}
+
+function fromArrayLike(obj) {
+  if (obj.length <= 0) return BufferFrom4(0);
+  if (obj.length < Buffer.poolSize >>> 1) {
+    //   if (obj.length > poolSize - poolOffset) createPool();
+    //   const b = new FastBuffer(allocPool, poolOffset, obj.length);
+    //   TypedArrayPrototypeSet(b, obj, 0);
+    //   poolOffset += obj.length;
+    //   alignPool();
+    //   return b;
+  }
+  return BufferFrom1(obj);
+}
+
+export default {
+  validateNumber,
+  validateInteger,
+  ERR_INVALID_ARG_TYPE,
+  ERR_OUT_OF_RANGE,
+  boundsError,
+  checkBounds,
+  checkInt,
+  check_read,
+  check_int8,
+  check_int16,
+  check_int24,
+  check_int32,
+  check_int40,
+  check_int48,
+  check_bigint64,
+  fromString,
+  fromObject,
+  fromArrayBuffer,
+};
diff --git a/test/js/node/buffer.test.js b/test/js/node/buffer.test.js
index 08830c4bfc8736..b627b1b56f11c4 100644
--- a/test/js/node/buffer.test.js
+++ b/test/js/node/buffer.test.js
@@ -1,6 +1,7 @@
 import { Buffer, SlowBuffer, isAscii, isUtf8, kMaxLength } from "buffer";
 import { afterEach, beforeEach, describe, expect, it } from "bun:test";
 import { gc } from "harness";
+import vm from "node:vm";
 
 const BufferModule = await import("buffer");
 
@@ -21,7 +22,7 @@ afterEach(() => gc());
 const NumberIsInteger = Number.isInteger;
 class ERR_INVALID_ARG_TYPE extends TypeError {
   constructor() {
-    super("Invalid arg type" + Array.prototype.join.call(arguments, " "));
+    super(`The "${arguments[0]}" argument must be of type ${arguments[1]}. Received (${Bun.inspect(arguments[2])})`);
     this.code = "ERR_INVALID_ARG_TYPE";
   }
 }
@@ -269,7 +270,7 @@ for (let withOverridenBufferWrite of [false, true]) {
         // Invalid encoding for Buffer.write
         expect(() => b.write("test string", 0, 5, "invalid")).toThrow(/encoding/);
         // Unsupported arguments for Buffer.write
-        expect(() => b.write("test", "utf8", 0)).toThrow(/invalid/i);
+        expect(() => b.write("test", "utf8", 0)).toThrow(/The "offset" argument must be of type number. Received /);
       });
 
       it("create 0-length buffers", () => {
@@ -1205,7 +1206,7 @@ for (let withOverridenBufferWrite of [false, true]) {
       it("toLocaleString()", () => {
         const buf = Buffer.from("test");
         expect(buf.toLocaleString()).toBe(buf.toString());
-        // expect(Buffer.prototype.toLocaleString).toBe(Buffer.prototype.toString);
+        expect(Buffer.prototype.toLocaleString).toBe(Buffer.prototype.toString);
       });
 
       it("alloc() should throw on invalid data", () => {
@@ -2116,7 +2117,7 @@ for (let withOverridenBufferWrite of [false, true]) {
         const buf = Buffer.from(ab);
 
         expect(buf instanceof Buffer).toBe(true);
-        // expect(buf.parent, buf.buffer);
+        expect(buf.parent, buf.buffer);
         expect(buf.buffer).toBe(ab);
         expect(buf.length).toBe(ab.byteLength);
 
@@ -2136,12 +2137,12 @@ for (let withOverridenBufferWrite of [false, true]) {
 
         // Now test protecting users from doing stupid things
 
-        // expect(function () {
-        //   function AB() {}
-        //   Object.setPrototypeOf(AB, ArrayBuffer);
-        //   Object.setPrototypeOf(AB.prototype, ArrayBuffer.prototype);
-        //   // Buffer.from(new AB());
-        // }).toThrow();
+        expect(function () {
+          function AB() {}
+          Object.setPrototypeOf(AB, ArrayBuffer);
+          Object.setPrototypeOf(AB.prototype, ArrayBuffer.prototype);
+          Buffer.from(new AB());
+        }).toThrow();
         // console.log(origAB !== ab);
 
         // Test the byteOffset and length arguments
@@ -2670,8 +2671,8 @@ for (let withOverridenBufferWrite of [false, true]) {
           });
 
         // Test that ArrayBuffer from a different context is detected correctly
-        // const arrayBuf = vm.runInNewContext("new ArrayBuffer()");
-        // expect(Buffer.byteLength(arrayBuf)).toBe(0);
+        const arrayBuf = vm.runInNewContext("new ArrayBuffer()");
+        expect(Buffer.byteLength(arrayBuf)).toBe(0);
 
         // Verify that invalid encodings are treated as utf8
         for (let i = 1; i < 10; i++) {
diff --git a/test/js/node/child_process/child_process-node.test.js b/test/js/node/child_process/child_process-node.test.js
index 42931a8dcf0a06..1d4a7a430557a6 100644
--- a/test/js/node/child_process/child_process-node.test.js
+++ b/test/js/node/child_process/child_process-node.test.js
@@ -659,7 +659,7 @@ describe("fork", () => {
             code: "ERR_INVALID_ARG_TYPE",
             name: "TypeError",
             message: expect.stringContaining(
-              `The "modulePath" argument must be of type string, Buffer or URL. Received: `,
+              `The "modulePath" argument must be of type string, Buffer, or URL. Received `,
             ),
           }),
         );
@@ -718,7 +718,7 @@ describe("fork", () => {
           expect.objectContaining({
             code: "ERR_INVALID_ARG_TYPE",
             name: "TypeError",
-            message: expect.stringContaining(`The "options" argument must be of type object. Received: `),
+            message: expect.stringContaining(`The "options" argument must be of type object. Received `),
           }),
         );
       });
diff --git a/test/js/node/child_process/child_process.test.ts b/test/js/node/child_process/child_process.test.ts
index f70772d4218971..a259c6897da066 100644
--- a/test/js/node/child_process/child_process.test.ts
+++ b/test/js/node/child_process/child_process.test.ts
@@ -96,7 +96,7 @@ describe("spawn()", () => {
   it("should disallow invalid filename", () => {
     // @ts-ignore
     expect(() => spawn(123)).toThrow({
-      message: 'The "file" argument must be of type string. Received 123',
+      message: 'The "file" argument must be of type string. Received type number (123)',
       code: "ERR_INVALID_ARG_TYPE",
     });
   });
diff --git a/test/js/node/test/common/index.js b/test/js/node/test/common/index.js
index 6b5d1079ffad7b..8385945cde2024 100644
--- a/test/js/node/test/common/index.js
+++ b/test/js/node/test/common/index.js
@@ -30,7 +30,7 @@ const net = require('net');
 // Do not require 'os' until needed so that test-os-checked-function can
 // monkey patch it. If 'os' is required here, that test will fail.
 const path = require('path');
-const { inspect } = require('util');
+const inspect = Bun.inspect; // const { inspect } = require('util');
 const { isMainThread } = require('worker_threads');
 const { isModuleNamespaceObject } = require('util/types');
 
@@ -888,13 +888,14 @@ function invalidArgTypeHelper(input) {
     return ` Received ${input}`;
   }
   if (typeof input === 'function') {
-    return ` Received function ${input.name}`;
+    if (input.name) return ` Received function ${input.name}`;
+    return ` Received function`;
   }
   if (typeof input === 'object') {
     if (input.constructor?.name) {
       return ` Received an instance of ${input.constructor.name}`;
     }
-    return ` Received ${inspect(input, { depth: -1 })}`;
+    return ` Received ${inspect(input, { depth: 0 })}`;
   }
 
   let inspected = inspect(input, { colors: false });
diff --git a/test/js/node/test/parallel/test-buffer-alloc.js b/test/js/node/test/parallel/test-buffer-alloc.js
new file mode 100644
index 00000000000000..faca8fe4549775
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-alloc.js
@@ -0,0 +1,1199 @@
+'use strict';
+const common = require('../common');
+
+const assert = require('assert');
+const vm = require('vm');
+
+const {
+  SlowBuffer,
+  kMaxLength,
+} = require('buffer');
+
+// Verify the maximum Uint8Array size. There is no concrete limit by spec. The
+// internal limits should be updated if this fails.
+assert.throws(
+  () => new Uint8Array(kMaxLength + 1),
+  { message: `length too large: ${kMaxLength + 1}` },
+);
+
+const b = Buffer.allocUnsafe(1024);
+assert.strictEqual(b.length, 1024);
+
+b[0] = -1;
+assert.strictEqual(b[0], 255);
+
+for (let i = 0; i < 1024; i++) {
+  b[i] = i % 256;
+}
+
+for (let i = 0; i < 1024; i++) {
+  assert.strictEqual(i % 256, b[i]);
+}
+
+const c = Buffer.allocUnsafe(512);
+assert.strictEqual(c.length, 512);
+
+const d = Buffer.from([]);
+assert.strictEqual(d.length, 0);
+
+// Test offset properties
+{
+  const b = Buffer.alloc(128);
+  assert.strictEqual(b.length, 128);
+  assert.strictEqual(b.byteOffset, 0);
+  assert.strictEqual(b.offset, 0);
+}
+
+// Test creating a Buffer from a Uint8Array
+{
+  const ui8 = new Uint8Array(4).fill(42);
+  const e = Buffer.from(ui8);
+  for (const [index, value] of e.entries()) {
+    assert.strictEqual(value, ui8[index]);
+  }
+}
+// Test creating a Buffer from a Uint8Array (old constructor)
+{
+  const ui8 = new Uint8Array(4).fill(42);
+  const e = Buffer(ui8);
+  for (const [key, value] of e.entries()) {
+    assert.strictEqual(value, ui8[key]);
+  }
+}
+
+// Test creating a Buffer from a Uint32Array
+// Note: it is implicitly interpreted as Array of integers modulo 256
+{
+  const ui32 = new Uint32Array(4).fill(42);
+  const e = Buffer.from(ui32);
+  for (const [index, value] of e.entries()) {
+    assert.strictEqual(value, ui32[index]);
+  }
+}
+// Test creating a Buffer from a Uint32Array (old constructor)
+// Note: it is implicitly interpreted as Array of integers modulo 256
+{
+  const ui32 = new Uint32Array(4).fill(42);
+  const e = Buffer(ui32);
+  for (const [key, value] of e.entries()) {
+    assert.strictEqual(value, ui32[key]);
+  }
+}
+
+// Test invalid encoding for Buffer.toString
+assert.throws(() => b.toString('invalid'),
+              /Unknown encoding: invalid/);
+// Invalid encoding for Buffer.write
+assert.throws(() => b.write('test string', 0, 5, 'invalid'),
+              /Unknown encoding: invalid/);
+// Unsupported arguments for Buffer.write
+assert.throws(() => b.write('test', 'utf8', 0),
+              { code: 'ERR_INVALID_ARG_TYPE' });
+
+// Try to create 0-length buffers. Should not throw.
+Buffer.from('');
+Buffer.from('', 'ascii');
+Buffer.from('', 'latin1');
+Buffer.alloc(0);
+Buffer.allocUnsafe(0);
+new Buffer('');
+new Buffer('', 'ascii');
+new Buffer('', 'latin1');
+new Buffer('', 'binary');
+Buffer(0);
+
+const outOfRangeError = {
+  // code: 'ERR_OUT_OF_RANGE', // TODO:
+  name: 'RangeError'
+};
+
+// Try to write a 0-length string beyond the end of b
+assert.throws(() => b.write('', 2048), outOfRangeError);
+
+// Throw when writing to negative offset
+assert.throws(() => b.write('a', -1), outOfRangeError);
+
+// Throw when writing past bounds from the pool
+assert.throws(() => b.write('a', 2048), outOfRangeError);
+
+// Throw when writing to negative offset
+assert.throws(() => b.write('a', -1), outOfRangeError);
+
+// Try to copy 0 bytes worth of data into an empty buffer
+b.copy(Buffer.alloc(0), 0, 0, 0);
+
+// Try to copy 0 bytes past the end of the target buffer
+b.copy(Buffer.alloc(0), 1, 1, 1);
+b.copy(Buffer.alloc(1), 1, 1, 1);
+
+// Try to copy 0 bytes from past the end of the source buffer
+b.copy(Buffer.alloc(1), 0, 1024, 1024);
+
+// Testing for smart defaults and ability to pass string values as offset
+{
+  const writeTest = Buffer.from('abcdes');
+  writeTest.write('n', 'ascii');
+  assert.throws(
+    () => writeTest.write('o', '1', 'ascii'),
+    { code: 'ERR_INVALID_ARG_TYPE' }
+  );
+  writeTest.write('o', 1, 'ascii');
+  writeTest.write('d', 2, 'ascii');
+  writeTest.write('e', 3, 'ascii');
+  writeTest.write('j', 4, 'ascii');
+  assert.strictEqual(writeTest.toString(), 'nodejs');
+}
+
+// Offset points to the end of the buffer and does not throw.
+// (see https://github.com/nodejs/node/issues/8127).
+Buffer.alloc(1).write('', 1, 0);
+
+// ASCII slice test
+{
+  const asciiString = 'hello world';
+
+  for (let i = 0; i < asciiString.length; i++) {
+    b[i] = asciiString.charCodeAt(i);
+  }
+  const asciiSlice = b.toString('ascii', 0, asciiString.length);
+  assert.strictEqual(asciiString, asciiSlice);
+}
+
+{
+  const asciiString = 'hello world';
+  const offset = 100;
+
+  assert.strictEqual(asciiString.length, b.write(asciiString, offset, 'ascii'));
+  const asciiSlice = b.toString('ascii', offset, offset + asciiString.length);
+  assert.strictEqual(asciiString, asciiSlice);
+}
+
+{
+  const asciiString = 'hello world';
+  const offset = 100;
+
+  const sliceA = b.slice(offset, offset + asciiString.length);
+  const sliceB = b.slice(offset, offset + asciiString.length);
+  for (let i = 0; i < asciiString.length; i++) {
+    assert.strictEqual(sliceA[i], sliceB[i]);
+  }
+}
+
+// UTF-8 slice test
+{
+  const utf8String = '¡hέlló wôrld!';
+  const offset = 100;
+
+  b.write(utf8String, 0, Buffer.byteLength(utf8String), 'utf8');
+  let utf8Slice = b.toString('utf8', 0, Buffer.byteLength(utf8String));
+  assert.strictEqual(utf8String, utf8Slice);
+
+  assert.strictEqual(Buffer.byteLength(utf8String),
+                     b.write(utf8String, offset, 'utf8'));
+  utf8Slice = b.toString('utf8', offset,
+                         offset + Buffer.byteLength(utf8String));
+  assert.strictEqual(utf8String, utf8Slice);
+
+  const sliceA = b.slice(offset, offset + Buffer.byteLength(utf8String));
+  const sliceB = b.slice(offset, offset + Buffer.byteLength(utf8String));
+  for (let i = 0; i < Buffer.byteLength(utf8String); i++) {
+    assert.strictEqual(sliceA[i], sliceB[i]);
+  }
+}
+
+{
+  const slice = b.slice(100, 150);
+  assert.strictEqual(slice.length, 50);
+  for (let i = 0; i < 50; i++) {
+    assert.strictEqual(b[100 + i], slice[i]);
+  }
+}
+
+{
+  // Make sure only top level parent propagates from allocPool
+  const b = Buffer.allocUnsafe(5);
+  const c = b.slice(0, 4);
+  const d = c.slice(0, 2);
+  assert.strictEqual(b.parent, c.parent);
+  assert.strictEqual(b.parent, d.parent);
+}
+
+{
+  // Also from a non-pooled instance
+  const b = Buffer.allocUnsafeSlow(5);
+  const c = b.slice(0, 4);
+  const d = c.slice(0, 2);
+  assert.strictEqual(c.parent, d.parent);
+}
+
+{
+  // Bug regression test
+  const testValue = '\u00F6\u65E5\u672C\u8A9E'; // ö日本語
+  const buffer = Buffer.allocUnsafe(32);
+  const size = buffer.write(testValue, 0, 'utf8');
+  const slice = buffer.toString('utf8', 0, size);
+  assert.strictEqual(slice, testValue);
+}
+
+{
+  // Test triple  slice
+  const a = Buffer.allocUnsafe(8);
+  for (let i = 0; i < 8; i++) a[i] = i;
+  const b = a.slice(4, 8);
+  assert.strictEqual(b[0], 4);
+  assert.strictEqual(b[1], 5);
+  assert.strictEqual(b[2], 6);
+  assert.strictEqual(b[3], 7);
+  const c = b.slice(2, 4);
+  assert.strictEqual(c[0], 6);
+  assert.strictEqual(c[1], 7);
+}
+
+{
+  const d = Buffer.from([23, 42, 255]);
+  assert.strictEqual(d.length, 3);
+  assert.strictEqual(d[0], 23);
+  assert.strictEqual(d[1], 42);
+  assert.strictEqual(d[2], 255);
+  assert.deepStrictEqual(d, Buffer.from(d));
+}
+
+{
+  // Test for proper UTF-8 Encoding
+  const e = Buffer.from('über');
+  assert.deepStrictEqual(e, Buffer.from([195, 188, 98, 101, 114]));
+}
+
+{
+  // Test for proper ascii Encoding, length should be 4
+  const f = Buffer.from('über', 'ascii');
+  assert.deepStrictEqual(f, Buffer.from([252, 98, 101, 114]));
+}
+
+['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach((encoding) => {
+  {
+    // Test for proper UTF16LE encoding, length should be 8
+    const f = Buffer.from('über', encoding);
+    assert.deepStrictEqual(f, Buffer.from([252, 0, 98, 0, 101, 0, 114, 0]));
+  }
+
+  {
+    // Length should be 12
+    const f = Buffer.from('привет', encoding);
+    assert.deepStrictEqual(
+      f, Buffer.from([63, 4, 64, 4, 56, 4, 50, 4, 53, 4, 66, 4])
+    );
+    assert.strictEqual(f.toString(encoding), 'привет');
+  }
+
+  {
+    const f = Buffer.from([0, 0, 0, 0, 0]);
+    assert.strictEqual(f.length, 5);
+    const size = f.write('あいうえお', encoding);
+    assert.strictEqual(size, 4);
+    assert.deepStrictEqual(f, Buffer.from([0x42, 0x30, 0x44, 0x30, 0x00]));
+  }
+});
+
+{
+  const f = Buffer.from('\uD83D\uDC4D', 'utf-16le'); // THUMBS UP SIGN (U+1F44D)
+  assert.strictEqual(f.length, 4);
+  assert.deepStrictEqual(f, Buffer.from('3DD84DDC', 'hex'));
+}
+
+// Test construction from arrayish object
+{
+  const arrayIsh = { 0: 0, 1: 1, 2: 2, 3: 3, length: 4 };
+  let g = Buffer.from(arrayIsh);
+  assert.deepStrictEqual(g, Buffer.from([0, 1, 2, 3]));
+  const strArrayIsh = { 0: '0', 1: '1', 2: '2', 3: '3', length: 4 };
+  g = Buffer.from(strArrayIsh);
+  assert.deepStrictEqual(g, Buffer.from([0, 1, 2, 3]));
+}
+
+//
+// Test toString('base64')
+//
+assert.strictEqual((Buffer.from('Man')).toString('base64'), 'TWFu');
+assert.strictEqual((Buffer.from('Woman')).toString('base64'), 'V29tYW4=');
+
+//
+// Test toString('base64url')
+//
+assert.strictEqual((Buffer.from('Man')).toString('base64url'), 'TWFu');
+assert.strictEqual((Buffer.from('Woman')).toString('base64url'), 'V29tYW4');
+
+{
+  // Test that regular and URL-safe base64 both work both ways
+  const expected = [0xff, 0xff, 0xbe, 0xff, 0xef, 0xbf, 0xfb, 0xef, 0xff];
+  assert.deepStrictEqual(Buffer.from('//++/++/++//', 'base64'),
+                         Buffer.from(expected));
+  assert.deepStrictEqual(Buffer.from('__--_--_--__', 'base64'),
+                         Buffer.from(expected));
+  assert.deepStrictEqual(Buffer.from('//++/++/++//', 'base64url'),
+                         Buffer.from(expected));
+  assert.deepStrictEqual(Buffer.from('__--_--_--__', 'base64url'),
+                         Buffer.from(expected));
+}
+
+const base64flavors = ['base64', 'base64url'];
+
+{
+  // Test that regular and URL-safe base64 both work both ways with padding
+  const expected = [0xff, 0xff, 0xbe, 0xff, 0xef, 0xbf, 0xfb, 0xef, 0xff, 0xfb];
+  assert.deepStrictEqual(Buffer.from('//++/++/++//+w==', 'base64'),
+                         Buffer.from(expected));
+  assert.deepStrictEqual(Buffer.from('//++/++/++//+w==', 'base64'),
+                         Buffer.from(expected));
+  assert.deepStrictEqual(Buffer.from('//++/++/++//+w==', 'base64url'),
+                         Buffer.from(expected));
+  assert.deepStrictEqual(Buffer.from('//++/++/++//+w==', 'base64url'),
+                         Buffer.from(expected));
+}
+
+{
+  // big example
+  const quote = 'Man is distinguished, not only by his reason, but by this ' +
+                'singular passion from other animals, which is a lust ' +
+                'of the mind, that by a perseverance of delight in the ' +
+                'continued and indefatigable generation of knowledge, ' +
+                'exceeds the short vehemence of any carnal pleasure.';
+  const expected = 'TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb' +
+                   '24sIGJ1dCBieSB0aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlci' +
+                   'BhbmltYWxzLCB3aGljaCBpcyBhIGx1c3Qgb2YgdGhlIG1pbmQsIHRoYXQ' +
+                   'gYnkgYSBwZXJzZXZlcmFuY2Ugb2YgZGVsaWdodCBpbiB0aGUgY29udGlu' +
+                   'dWVkIGFuZCBpbmRlZmF0aWdhYmxlIGdlbmVyYXRpb24gb2Yga25vd2xlZ' +
+                   'GdlLCBleGNlZWRzIHRoZSBzaG9ydCB2ZWhlbWVuY2Ugb2YgYW55IGNhcm' +
+                   '5hbCBwbGVhc3VyZS4=';
+  assert.strictEqual(Buffer.from(quote).toString('base64'), expected);
+  assert.strictEqual(
+    Buffer.from(quote).toString('base64url'),
+    expected.replaceAll('+', '-').replaceAll('/', '_').replaceAll('=', '')
+  );
+
+  base64flavors.forEach((encoding) => {
+    let b = Buffer.allocUnsafe(1024);
+    let bytesWritten = b.write(expected, 0, encoding);
+    assert.strictEqual(quote.length, bytesWritten);
+    assert.strictEqual(quote, b.toString('ascii', 0, quote.length));
+
+    // Check that the base64 decoder ignores whitespace
+    const expectedWhite = `${expected.slice(0, 60)} \n` +
+                          `${expected.slice(60, 120)} \n` +
+                          `${expected.slice(120, 180)} \n` +
+                          `${expected.slice(180, 240)} \n` +
+                          `${expected.slice(240, 300)}\n` +
+                          `${expected.slice(300, 360)}\n`;
+    b = Buffer.allocUnsafe(1024);
+    bytesWritten = b.write(expectedWhite, 0, encoding);
+    assert.strictEqual(quote.length, bytesWritten);
+    assert.strictEqual(quote, b.toString('ascii', 0, quote.length));
+
+    // Check that the base64 decoder on the constructor works
+    // even in the presence of whitespace.
+    b = Buffer.from(expectedWhite, encoding);
+    assert.strictEqual(quote.length, b.length);
+    assert.strictEqual(quote, b.toString('ascii', 0, quote.length));
+
+    // Check that the base64 decoder ignores illegal chars
+    const expectedIllegal = expected.slice(0, 60) + ' \x80' +
+                            expected.slice(60, 120) + ' \xff' +
+                            expected.slice(120, 180) + ' \x00' +
+                            expected.slice(180, 240) + ' \x98' +
+                            expected.slice(240, 300) + '\x03' +
+                            expected.slice(300, 360);
+    b = Buffer.from(expectedIllegal, encoding);
+    assert.strictEqual(quote.length, b.length);
+    assert.strictEqual(quote, b.toString('ascii', 0, quote.length));
+  });
+}
+
+base64flavors.forEach((encoding) => {
+  assert.strictEqual(Buffer.from('', encoding).toString(), '');
+  assert.strictEqual(Buffer.from('K', encoding).toString(), '');
+
+  // multiple-of-4 with padding
+  assert.strictEqual(Buffer.from('Kg==', encoding).toString(), '*');
+  assert.strictEqual(Buffer.from('Kio=', encoding).toString(), '*'.repeat(2));
+  assert.strictEqual(Buffer.from('Kioq', encoding).toString(), '*'.repeat(3));
+  assert.strictEqual(
+    Buffer.from('KioqKg==', encoding).toString(), '*'.repeat(4));
+  assert.strictEqual(
+    Buffer.from('KioqKio=', encoding).toString(), '*'.repeat(5));
+  assert.strictEqual(
+    Buffer.from('KioqKioq', encoding).toString(), '*'.repeat(6));
+  assert.strictEqual(Buffer.from('KioqKioqKg==', encoding).toString(),
+                     '*'.repeat(7));
+  assert.strictEqual(Buffer.from('KioqKioqKio=', encoding).toString(),
+                     '*'.repeat(8));
+  assert.strictEqual(Buffer.from('KioqKioqKioq', encoding).toString(),
+                     '*'.repeat(9));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKg==', encoding).toString(),
+                     '*'.repeat(10));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKio=', encoding).toString(),
+                     '*'.repeat(11));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKioq', encoding).toString(),
+                     '*'.repeat(12));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKg==', encoding).toString(),
+                     '*'.repeat(13));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKio=', encoding).toString(),
+                     '*'.repeat(14));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioq', encoding).toString(),
+                     '*'.repeat(15));
+  assert.strictEqual(
+    Buffer.from('KioqKioqKioqKioqKioqKg==', encoding).toString(),
+    '*'.repeat(16));
+  assert.strictEqual(
+    Buffer.from('KioqKioqKioqKioqKioqKio=', encoding).toString(),
+    '*'.repeat(17));
+  assert.strictEqual(
+    Buffer.from('KioqKioqKioqKioqKioqKioq', encoding).toString(),
+    '*'.repeat(18));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKioqKg==',
+                                 encoding).toString(),
+                     '*'.repeat(19));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKioqKio=',
+                                 encoding).toString(),
+                     '*'.repeat(20));
+
+  // No padding, not a multiple of 4
+  assert.strictEqual(Buffer.from('Kg', encoding).toString(), '*');
+  assert.strictEqual(Buffer.from('Kio', encoding).toString(), '*'.repeat(2));
+  assert.strictEqual(Buffer.from('KioqKg', encoding).toString(), '*'.repeat(4));
+  assert.strictEqual(
+    Buffer.from('KioqKio', encoding).toString(), '*'.repeat(5));
+  assert.strictEqual(Buffer.from('KioqKioqKg', encoding).toString(),
+                     '*'.repeat(7));
+  assert.strictEqual(Buffer.from('KioqKioqKio', encoding).toString(),
+                     '*'.repeat(8));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKg', encoding).toString(),
+                     '*'.repeat(10));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKio', encoding).toString(),
+                     '*'.repeat(11));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKg', encoding).toString(),
+                     '*'.repeat(13));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKio', encoding).toString(),
+                     '*'.repeat(14));
+  assert.strictEqual(Buffer.from('KioqKioqKioqKioqKioqKg', encoding).toString(),
+                     '*'.repeat(16));
+  assert.strictEqual(
+    Buffer.from('KioqKioqKioqKioqKioqKio', encoding).toString(),
+    '*'.repeat(17));
+  assert.strictEqual(
+    Buffer.from('KioqKioqKioqKioqKioqKioqKg', encoding).toString(),
+    '*'.repeat(19));
+  assert.strictEqual(
+    Buffer.from('KioqKioqKioqKioqKioqKioqKio', encoding).toString(),
+    '*'.repeat(20));
+});
+
+// Handle padding graciously, multiple-of-4 or not
+assert.strictEqual(
+  Buffer.from('72INjkR5fchcxk9+VgdGPFJDxUBFR5/rMFsghgxADiw==', 'base64').length,
+  32
+);
+assert.strictEqual(
+  Buffer.from('72INjkR5fchcxk9-VgdGPFJDxUBFR5_rMFsghgxADiw==', 'base64url')
+    .length,
+  32
+);
+assert.strictEqual(
+  Buffer.from('72INjkR5fchcxk9+VgdGPFJDxUBFR5/rMFsghgxADiw=', 'base64').length,
+  32
+);
+assert.strictEqual(
+  Buffer.from('72INjkR5fchcxk9-VgdGPFJDxUBFR5_rMFsghgxADiw=', 'base64url')
+    .length,
+  32
+);
+assert.strictEqual(
+  Buffer.from('72INjkR5fchcxk9+VgdGPFJDxUBFR5/rMFsghgxADiw', 'base64').length,
+  32
+);
+assert.strictEqual(
+  Buffer.from('72INjkR5fchcxk9-VgdGPFJDxUBFR5_rMFsghgxADiw', 'base64url')
+    .length,
+  32
+);
+assert.strictEqual(
+  Buffer.from('w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg==', 'base64').length,
+  31
+);
+assert.strictEqual(
+  Buffer.from('w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg==', 'base64url')
+    .length,
+  31
+);
+assert.strictEqual(
+  Buffer.from('w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg=', 'base64').length,
+  31
+);
+assert.strictEqual(
+  Buffer.from('w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg=', 'base64url')
+    .length,
+  31
+);
+assert.strictEqual(
+  Buffer.from('w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg', 'base64').length,
+  31
+);
+assert.strictEqual(
+  Buffer.from('w69jACy6BgZmaFvv96HG6MYksWytuZu3T1FvGnulPg', 'base64url').length,
+  31
+);
+
+{
+// This string encodes single '.' character in UTF-16
+  const dot = Buffer.from('//4uAA==', 'base64');
+  assert.strictEqual(dot[0], 0xff);
+  assert.strictEqual(dot[1], 0xfe);
+  assert.strictEqual(dot[2], 0x2e);
+  assert.strictEqual(dot[3], 0x00);
+  assert.strictEqual(dot.toString('base64'), '//4uAA==');
+}
+
+{
+// This string encodes single '.' character in UTF-16
+  const dot = Buffer.from('//4uAA', 'base64url');
+  assert.strictEqual(dot[0], 0xff);
+  assert.strictEqual(dot[1], 0xfe);
+  assert.strictEqual(dot[2], 0x2e);
+  assert.strictEqual(dot[3], 0x00);
+  assert.strictEqual(dot.toString('base64url'), '__4uAA');
+}
+
+{
+  // Writing base64 at a position > 0 should not mangle the result.
+  //
+  // https://github.com/joyent/node/issues/402
+  const segments = ['TWFkbmVzcz8h', 'IFRoaXM=', 'IGlz', 'IG5vZGUuanMh'];
+  const b = Buffer.allocUnsafe(64);
+  let pos = 0;
+
+  for (let i = 0; i < segments.length; ++i) {
+    pos += b.write(segments[i], pos, 'base64');
+  }
+  assert.strictEqual(b.toString('latin1', 0, pos),
+                     'Madness?! This is node.js!');
+}
+
+{
+  // Writing base64url at a position > 0 should not mangle the result.
+  //
+  // https://github.com/joyent/node/issues/402
+  const segments = ['TWFkbmVzcz8h', 'IFRoaXM', 'IGlz', 'IG5vZGUuanMh'];
+  const b = Buffer.allocUnsafe(64);
+  let pos = 0;
+
+  for (let i = 0; i < segments.length; ++i) {
+    pos += b.write(segments[i], pos, 'base64url');
+  }
+  assert.strictEqual(b.toString('latin1', 0, pos),
+                     'Madness?! This is node.js!');
+}
+
+// Regression test for https://github.com/nodejs/node/issues/3496.
+assert.strictEqual(Buffer.from('=bad'.repeat(1e4), 'base64').length, 0);
+
+// Regression test for https://github.com/nodejs/node/issues/11987.
+assert.deepStrictEqual(Buffer.from('w0  ', 'base64'),
+                       Buffer.from('w0', 'base64'));
+
+// Regression test for https://github.com/nodejs/node/issues/13657.
+assert.deepStrictEqual(Buffer.from(' YWJvcnVtLg', 'base64'),
+                       Buffer.from('YWJvcnVtLg', 'base64'));
+
+{
+  // Creating buffers larger than pool size.
+  const l = Buffer.poolSize + 5;
+  const s = 'h'.repeat(l);
+  const b = Buffer.from(s);
+
+  for (let i = 0; i < l; i++) {
+    assert.strictEqual(b[i], 'h'.charCodeAt(0));
+  }
+
+  const sb = b.toString();
+  assert.strictEqual(sb.length, s.length);
+  assert.strictEqual(sb, s);
+}
+
+{
+  // test hex toString
+  const hexb = Buffer.allocUnsafe(256);
+  for (let i = 0; i < 256; i++) {
+    hexb[i] = i;
+  }
+  const hexStr = hexb.toString('hex');
+  assert.strictEqual(hexStr,
+                     '000102030405060708090a0b0c0d0e0f' +
+                     '101112131415161718191a1b1c1d1e1f' +
+                     '202122232425262728292a2b2c2d2e2f' +
+                     '303132333435363738393a3b3c3d3e3f' +
+                     '404142434445464748494a4b4c4d4e4f' +
+                     '505152535455565758595a5b5c5d5e5f' +
+                     '606162636465666768696a6b6c6d6e6f' +
+                     '707172737475767778797a7b7c7d7e7f' +
+                     '808182838485868788898a8b8c8d8e8f' +
+                     '909192939495969798999a9b9c9d9e9f' +
+                     'a0a1a2a3a4a5a6a7a8a9aaabacadaeaf' +
+                     'b0b1b2b3b4b5b6b7b8b9babbbcbdbebf' +
+                     'c0c1c2c3c4c5c6c7c8c9cacbcccdcecf' +
+                     'd0d1d2d3d4d5d6d7d8d9dadbdcdddedf' +
+                     'e0e1e2e3e4e5e6e7e8e9eaebecedeeef' +
+                     'f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff');
+
+  const hexb2 = Buffer.from(hexStr, 'hex');
+  for (let i = 0; i < 256; i++) {
+    assert.strictEqual(hexb2[i], hexb[i]);
+  }
+}
+
+// Test single hex character is discarded.
+assert.strictEqual(Buffer.from('A', 'hex').length, 0);
+
+// Test that if a trailing character is discarded, rest of string is processed.
+assert.deepStrictEqual(Buffer.from('Abx', 'hex'), Buffer.from('Ab', 'hex'));
+
+// Test single base64 char encodes as 0.
+assert.strictEqual(Buffer.from('A', 'base64').length, 0);
+
+
+{
+  // Test an invalid slice end.
+  const b = Buffer.from([1, 2, 3, 4, 5]);
+  const b2 = b.toString('hex', 1, 10000);
+  const b3 = b.toString('hex', 1, 5);
+  const b4 = b.toString('hex', 1);
+  assert.strictEqual(b2, b3);
+  assert.strictEqual(b2, b4);
+}
+
+function buildBuffer(data) {
+  if (Array.isArray(data)) {
+    const buffer = Buffer.allocUnsafe(data.length);
+    data.forEach((v, k) => buffer[k] = v);
+    return buffer;
+  }
+  return null;
+}
+
+const x = buildBuffer([0x81, 0xa3, 0x66, 0x6f, 0x6f, 0xa3, 0x62, 0x61, 0x72]);
+
+assert.strictEqual(x.inspect(), 'Buffer(9) [ 129, 163, 102, 111, 111, 163, 98, 97, 114 ]');
+
+{
+  const z = x.slice(4);
+  assert.strictEqual(z.length, 5);
+  assert.strictEqual(z[0], 0x6f);
+  assert.strictEqual(z[1], 0xa3);
+  assert.strictEqual(z[2], 0x62);
+  assert.strictEqual(z[3], 0x61);
+  assert.strictEqual(z[4], 0x72);
+}
+
+{
+  const z = x.slice(0);
+  assert.strictEqual(z.length, x.length);
+}
+
+{
+  const z = x.slice(0, 4);
+  assert.strictEqual(z.length, 4);
+  assert.strictEqual(z[0], 0x81);
+  assert.strictEqual(z[1], 0xa3);
+}
+
+{
+  const z = x.slice(0, 9);
+  assert.strictEqual(z.length, 9);
+}
+
+{
+  const z = x.slice(1, 4);
+  assert.strictEqual(z.length, 3);
+  assert.strictEqual(z[0], 0xa3);
+}
+
+{
+  const z = x.slice(2, 4);
+  assert.strictEqual(z.length, 2);
+  assert.strictEqual(z[0], 0x66);
+  assert.strictEqual(z[1], 0x6f);
+}
+
+['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach((encoding) => {
+  const b = Buffer.allocUnsafe(10);
+  b.write('あいうえお', encoding);
+  assert.strictEqual(b.toString(encoding), 'あいうえお');
+});
+
+['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach((encoding) => {
+  const b = Buffer.allocUnsafe(11);
+  b.write('あいうえお', 1, encoding);
+  assert.strictEqual(b.toString(encoding, 1), 'あいうえお');
+});
+
+{
+  // latin1 encoding should write only one byte per character.
+  const b = Buffer.from([0xde, 0xad, 0xbe, 0xef]);
+  let s = String.fromCharCode(0xffff);
+  b.write(s, 0, 'latin1');
+  assert.strictEqual(b[0], 0xff);
+  assert.strictEqual(b[1], 0xad);
+  assert.strictEqual(b[2], 0xbe);
+  assert.strictEqual(b[3], 0xef);
+  s = String.fromCharCode(0xaaee);
+  b.write(s, 0, 'latin1');
+  assert.strictEqual(b[0], 0xee);
+  assert.strictEqual(b[1], 0xad);
+  assert.strictEqual(b[2], 0xbe);
+  assert.strictEqual(b[3], 0xef);
+}
+
+{
+  // Binary encoding should write only one byte per character.
+  const b = Buffer.from([0xde, 0xad, 0xbe, 0xef]);
+  let s = String.fromCharCode(0xffff);
+  b.write(s, 0, 'latin1');
+  assert.strictEqual(b[0], 0xff);
+  assert.strictEqual(b[1], 0xad);
+  assert.strictEqual(b[2], 0xbe);
+  assert.strictEqual(b[3], 0xef);
+  s = String.fromCharCode(0xaaee);
+  b.write(s, 0, 'latin1');
+  assert.strictEqual(b[0], 0xee);
+  assert.strictEqual(b[1], 0xad);
+  assert.strictEqual(b[2], 0xbe);
+  assert.strictEqual(b[3], 0xef);
+}
+
+{
+  // https://github.com/nodejs/node-v0.x-archive/pull/1210
+  // Test UTF-8 string includes null character
+  let buf = Buffer.from('\0');
+  assert.strictEqual(buf.length, 1);
+  buf = Buffer.from('\0\0');
+  assert.strictEqual(buf.length, 2);
+}
+
+{
+  const buf = Buffer.allocUnsafe(2);
+  assert.strictEqual(buf.write(''), 0); // 0bytes
+  assert.strictEqual(buf.write('\0'), 1); // 1byte (v8 adds null terminator)
+  assert.strictEqual(buf.write('a\0'), 2); // 1byte * 2
+  assert.strictEqual(buf.write('あ'), 0); // 3bytes
+  assert.strictEqual(buf.write('\0あ'), 1); // 1byte + 3bytes
+  assert.strictEqual(buf.write('\0\0あ'), 2); // 1byte * 2 + 3bytes
+}
+
+{
+  const buf = Buffer.allocUnsafe(10);
+  assert.strictEqual(buf.write('あいう'), 9); // 3bytes * 3 (v8 adds null term.)
+  assert.strictEqual(buf.write('あいう\0'), 10); // 3bytes * 3 + 1byte
+}
+
+{
+  // https://github.com/nodejs/node-v0.x-archive/issues/243
+  // Test write() with maxLength
+  const buf = Buffer.allocUnsafe(4);
+  buf.fill(0xFF);
+  assert.strictEqual(buf.write('abcd', 1, 2, 'utf8'), 2);
+  assert.strictEqual(buf[0], 0xFF);
+  assert.strictEqual(buf[1], 0x61);
+  assert.strictEqual(buf[2], 0x62);
+  assert.strictEqual(buf[3], 0xFF);
+
+  buf.fill(0xFF);
+  assert.strictEqual(buf.write('abcd', 1, 4), 3);
+  assert.strictEqual(buf[0], 0xFF);
+  assert.strictEqual(buf[1], 0x61);
+  assert.strictEqual(buf[2], 0x62);
+  assert.strictEqual(buf[3], 0x63);
+
+  buf.fill(0xFF);
+  assert.strictEqual(buf.write('abcd', 1, 2, 'utf8'), 2);
+  assert.strictEqual(buf[0], 0xFF);
+  assert.strictEqual(buf[1], 0x61);
+  assert.strictEqual(buf[2], 0x62);
+  assert.strictEqual(buf[3], 0xFF);
+
+  buf.fill(0xFF);
+  assert.strictEqual(buf.write('abcdef', 1, 2, 'hex'), 2);
+  assert.strictEqual(buf[0], 0xFF);
+  assert.strictEqual(buf[1], 0xAB);
+  assert.strictEqual(buf[2], 0xCD);
+  assert.strictEqual(buf[3], 0xFF);
+
+  ['ucs2', 'ucs-2', 'utf16le', 'utf-16le'].forEach((encoding) => {
+    buf.fill(0xFF);
+    assert.strictEqual(buf.write('abcd', 0, 2, encoding), 2);
+    assert.strictEqual(buf[0], 0x61);
+    assert.strictEqual(buf[1], 0x00);
+    assert.strictEqual(buf[2], 0xFF);
+    assert.strictEqual(buf[3], 0xFF);
+  });
+}
+
+{
+  // Test offset returns are correct
+  const b = Buffer.allocUnsafe(16);
+  assert.strictEqual(b.writeUInt32LE(0, 0), 4);
+  assert.strictEqual(b.writeUInt16LE(0, 4), 6);
+  assert.strictEqual(b.writeUInt8(0, 6), 7);
+  assert.strictEqual(b.writeInt8(0, 7), 8);
+  assert.strictEqual(b.writeDoubleLE(0, 8), 16);
+}
+
+{
+  // Test unmatched surrogates not producing invalid utf8 output
+  // ef bf bd = utf-8 representation of unicode replacement character
+  // see https://codereview.chromium.org/121173009/
+  const buf = Buffer.from('ab\ud800cd', 'utf8');
+  assert.strictEqual(buf[0], 0x61);
+  assert.strictEqual(buf[1], 0x62);
+  assert.strictEqual(buf[2], 0xef);
+  assert.strictEqual(buf[3], 0xbf);
+  assert.strictEqual(buf[4], 0xbd);
+  assert.strictEqual(buf[5], 0x63);
+  assert.strictEqual(buf[6], 0x64);
+}
+
+{
+  // Test for buffer overrun
+  const buf = Buffer.from([0, 0, 0, 0, 0]); // length: 5
+  const sub = buf.slice(0, 4);         // length: 4
+  assert.strictEqual(sub.write('12345', 'latin1'), 4);
+  assert.strictEqual(buf[4], 0);
+  assert.strictEqual(sub.write('12345', 'binary'), 4);
+  assert.strictEqual(buf[4], 0);
+}
+
+{
+  // Test alloc with fill option
+  const buf = Buffer.alloc(5, '800A', 'hex');
+  assert.strictEqual(buf[0], 128);
+  assert.strictEqual(buf[1], 10);
+  assert.strictEqual(buf[2], 128);
+  assert.strictEqual(buf[3], 10);
+  assert.strictEqual(buf[4], 128);
+}
+
+
+// Check for fractional length args, junk length args, etc.
+// https://github.com/joyent/node/issues/1758
+
+// Call .fill() first, stops valgrind warning about uninitialized memory reads.
+Buffer.allocUnsafe(3.3).fill().toString();
+// Throws bad argument error in commit 43cb4ec
+Buffer.alloc(3.3).fill().toString();
+assert.strictEqual(Buffer.allocUnsafe(3.3).length, 3);
+assert.strictEqual(Buffer.from({ length: 3.3 }).length, 3);
+assert.strictEqual(Buffer.from({ length: 'BAM' }).length, 0);
+
+// Make sure that strings are not coerced to numbers.
+assert.strictEqual(Buffer.from('99').length, 2);
+assert.strictEqual(Buffer.from('13.37').length, 5);
+
+// Ensure that the length argument is respected.
+['ascii', 'utf8', 'hex', 'base64', 'latin1', 'binary'].forEach((enc) => {
+  assert.strictEqual(Buffer.allocUnsafe(1).write('aaaaaa', 0, 1, enc), 1);
+});
+
+{
+  // Regression test, guard against buffer overrun in the base64 decoder.
+  const a = Buffer.allocUnsafe(3);
+  const b = Buffer.from('xxx');
+  a.write('aaaaaaaa', 'base64');
+  assert.strictEqual(b.toString(), 'xxx');
+}
+
+// issue GH-3416
+Buffer.from(Buffer.allocUnsafe(0), 0, 0);
+
+// issue GH-5587
+assert.throws(
+  () => Buffer.alloc(8).writeFloatLE(0, 5),
+  outOfRangeError
+);
+assert.throws(
+  () => Buffer.alloc(16).writeDoubleLE(0, 9),
+  outOfRangeError
+);
+
+// Attempt to overflow buffers, similar to previous bug in array buffers
+assert.throws(
+  () => Buffer.allocUnsafe(8).writeFloatLE(0.0, 0xffffffff),
+  outOfRangeError
+);
+assert.throws(
+  () => Buffer.allocUnsafe(8).writeFloatLE(0.0, 0xffffffff),
+  outOfRangeError
+);
+
+// Ensure negative values can't get past offset
+assert.throws(
+  () => Buffer.allocUnsafe(8).writeFloatLE(0.0, -1),
+  outOfRangeError
+);
+assert.throws(
+  () => Buffer.allocUnsafe(8).writeFloatLE(0.0, -1),
+  outOfRangeError
+);
+
+// Test for common write(U)IntLE/BE
+{
+  let buf = Buffer.allocUnsafe(3);
+  buf.writeUIntLE(0x123456, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0x56, 0x34, 0x12]);
+  assert.strictEqual(buf.readUIntLE(0, 3), 0x123456);
+
+  buf.fill(0xFF);
+  buf.writeUIntBE(0x123456, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0x12, 0x34, 0x56]);
+  assert.strictEqual(buf.readUIntBE(0, 3), 0x123456);
+
+  buf.fill(0xFF);
+  buf.writeIntLE(0x123456, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0x56, 0x34, 0x12]);
+  assert.strictEqual(buf.readIntLE(0, 3), 0x123456);
+
+  buf.fill(0xFF);
+  buf.writeIntBE(0x123456, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0x12, 0x34, 0x56]);
+  assert.strictEqual(buf.readIntBE(0, 3), 0x123456);
+
+  buf.fill(0xFF);
+  buf.writeIntLE(-0x123456, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0xaa, 0xcb, 0xed]);
+  assert.strictEqual(buf.readIntLE(0, 3), -0x123456);
+
+  buf.fill(0xFF);
+  buf.writeIntBE(-0x123456, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0xed, 0xcb, 0xaa]);
+  assert.strictEqual(buf.readIntBE(0, 3), -0x123456);
+
+  buf.fill(0xFF);
+  buf.writeIntLE(-0x123400, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0x00, 0xcc, 0xed]);
+  assert.strictEqual(buf.readIntLE(0, 3), -0x123400);
+
+  buf.fill(0xFF);
+  buf.writeIntBE(-0x123400, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0xed, 0xcc, 0x00]);
+  assert.strictEqual(buf.readIntBE(0, 3), -0x123400);
+
+  buf.fill(0xFF);
+  buf.writeIntLE(-0x120000, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0x00, 0x00, 0xee]);
+  assert.strictEqual(buf.readIntLE(0, 3), -0x120000);
+
+  buf.fill(0xFF);
+  buf.writeIntBE(-0x120000, 0, 3);
+  assert.deepStrictEqual(buf.toJSON().data, [0xee, 0x00, 0x00]);
+  assert.strictEqual(buf.readIntBE(0, 3), -0x120000);
+
+  buf = Buffer.allocUnsafe(5);
+  buf.writeUIntLE(0x1234567890, 0, 5);
+  assert.deepStrictEqual(buf.toJSON().data, [0x90, 0x78, 0x56, 0x34, 0x12]);
+  assert.strictEqual(buf.readUIntLE(0, 5), 0x1234567890);
+
+  buf.fill(0xFF);
+  buf.writeUIntBE(0x1234567890, 0, 5);
+  assert.deepStrictEqual(buf.toJSON().data, [0x12, 0x34, 0x56, 0x78, 0x90]);
+  assert.strictEqual(buf.readUIntBE(0, 5), 0x1234567890);
+
+  buf.fill(0xFF);
+  buf.writeIntLE(0x1234567890, 0, 5);
+  assert.deepStrictEqual(buf.toJSON().data, [0x90, 0x78, 0x56, 0x34, 0x12]);
+  assert.strictEqual(buf.readIntLE(0, 5), 0x1234567890);
+
+  buf.fill(0xFF);
+  buf.writeIntBE(0x1234567890, 0, 5);
+  assert.deepStrictEqual(buf.toJSON().data, [0x12, 0x34, 0x56, 0x78, 0x90]);
+  assert.strictEqual(buf.readIntBE(0, 5), 0x1234567890);
+
+  buf.fill(0xFF);
+  buf.writeIntLE(-0x1234567890, 0, 5);
+  assert.deepStrictEqual(buf.toJSON().data, [0x70, 0x87, 0xa9, 0xcb, 0xed]);
+  assert.strictEqual(buf.readIntLE(0, 5), -0x1234567890);
+
+  buf.fill(0xFF);
+  buf.writeIntBE(-0x1234567890, 0, 5);
+  assert.deepStrictEqual(buf.toJSON().data, [0xed, 0xcb, 0xa9, 0x87, 0x70]);
+  assert.strictEqual(buf.readIntBE(0, 5), -0x1234567890);
+
+  buf.fill(0xFF);
+  buf.writeIntLE(-0x0012000000, 0, 5);
+  assert.deepStrictEqual(buf.toJSON().data, [0x00, 0x00, 0x00, 0xee, 0xff]);
+  assert.strictEqual(buf.readIntLE(0, 5), -0x0012000000);
+
+  buf.fill(0xFF);
+  buf.writeIntBE(-0x0012000000, 0, 5);
+  assert.deepStrictEqual(buf.toJSON().data, [0xff, 0xee, 0x00, 0x00, 0x00]);
+  assert.strictEqual(buf.readIntBE(0, 5), -0x0012000000);
+}
+
+// Regression test for https://github.com/nodejs/node-v0.x-archive/issues/5482:
+// should throw but not assert in C++ land.
+assert.throws(
+  () => Buffer.from('', 'buffer'),
+  {
+    code: 'ERR_UNKNOWN_ENCODING',
+    name: 'TypeError',
+    message: 'Unknown encoding: buffer'
+  }
+);
+
+// Regression test for https://github.com/nodejs/node-v0.x-archive/issues/6111.
+// Constructing a buffer from another buffer should a) work, and b) not corrupt
+// the source buffer.
+{
+  const a = [...Array(128).keys()]; // [0, 1, 2, 3, ... 126, 127]
+  const b = Buffer.from(a);
+  const c = Buffer.from(b);
+  assert.strictEqual(b.length, a.length);
+  assert.strictEqual(c.length, a.length);
+  for (let i = 0, k = a.length; i < k; ++i) {
+    assert.strictEqual(a[i], i);
+    assert.strictEqual(b[i], i);
+    assert.strictEqual(c[i], i);
+  }
+}
+
+if (common.hasCrypto) { // eslint-disable-line node-core/crypto-check
+  // Test truncation after decode
+  const crypto = require('crypto');
+
+  const b1 = Buffer.from('YW55=======', 'base64');
+  const b2 = Buffer.from('YW55', 'base64');
+
+  assert.strictEqual(
+    crypto.createHash('sha1').update(b1).digest('hex'),
+    crypto.createHash('sha1').update(b2).digest('hex')
+  );
+} else {
+  common.printSkipMessage('missing crypto');
+}
+
+const ps = Buffer.poolSize;
+Buffer.poolSize = 0;
+assert(Buffer.allocUnsafe(1).parent instanceof ArrayBuffer);
+Buffer.poolSize = ps;
+
+assert.throws(
+  () => Buffer.allocUnsafe(10).copy(),
+  {
+    code: 'ERR_INVALID_ARG_TYPE',
+    name: 'TypeError',
+    message: 'The "target" argument must be an instance of Buffer or ' +
+             'Uint8Array. Received undefined'
+  });
+
+assert.throws(() => Buffer.from(), {
+  name: 'TypeError',
+  code: 'ERR_INVALID_ARG_TYPE',
+  message: 'The first argument must be of type string, Buffer, ArrayBuffer, Array, or Array-like Object. Received undefined'
+});
+assert.throws(() => Buffer.from(null), {
+  name: 'TypeError',
+  code: 'ERR_INVALID_ARG_TYPE',
+  message: 'The first argument must be of type string, Buffer, ArrayBuffer, Array, or Array-like Object. Received null'
+});
+
+// Test prototype getters don't throw
+assert.strictEqual(Buffer.prototype.parent, undefined);
+assert.strictEqual(Buffer.prototype.offset, undefined);
+assert.strictEqual(SlowBuffer.prototype.parent, undefined);
+assert.strictEqual(SlowBuffer.prototype.offset, undefined);
+
+
+{
+  // Test that large negative Buffer length inputs don't affect the pool offset.
+  // Use the fromArrayLike() variant here because it's more lenient
+  // about its input and passes the length directly to allocate().
+  assert.deepStrictEqual(Buffer.from({ length: -Buffer.poolSize }),
+                         Buffer.from(''));
+  assert.deepStrictEqual(Buffer.from({ length: -100 }),
+                         Buffer.from(''));
+
+  // Check pool offset after that by trying to write string into the pool.
+  Buffer.from('abc');
+}
+
+
+// Test that ParseArrayIndex handles full uint32
+{
+  const errMsg = common.expectsError({
+    code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+    name: 'RangeError',
+    message: '"offset" is outside of buffer bounds'
+  });
+  assert.throws(() => Buffer.from(new ArrayBuffer(0), -1 >>> 0), errMsg);
+}
+
+// ParseArrayIndex() should reject values that don't fit in a 32 bits size_t.
+assert.throws(() => {
+  const a = Buffer.alloc(1);
+  const b = Buffer.alloc(1);
+  a.copy(b, 0, 0x100000000, 0x100000001);
+}, outOfRangeError);
+
+// Unpooled buffer (replaces SlowBuffer)
+{
+  const ubuf = Buffer.allocUnsafeSlow(10);
+  assert(ubuf);
+  assert(ubuf.buffer);
+  assert.strictEqual(ubuf.buffer.byteLength, 10);
+}
+
+// Regression test to verify that an empty ArrayBuffer does not throw.
+Buffer.from(new ArrayBuffer());
+
+// Test that ArrayBuffer from a different context is detected correctly.
+const arrayBuf = vm.runInNewContext('new ArrayBuffer()');
+Buffer.from(arrayBuf);
+Buffer.from({ buffer: arrayBuf });
+
+assert.throws(() => Buffer.alloc({ valueOf: () => 1 }),
+              /"size" argument must be of type number/);
+assert.throws(() => Buffer.alloc({ valueOf: () => -1 }),
+              /"size" argument must be of type number/);
+
+assert.strictEqual(Buffer.prototype.toLocaleString, Buffer.prototype.toString);
+{
+  const buf = Buffer.from('test');
+  assert.strictEqual(buf.toLocaleString(), buf.toString());
+}
+
+assert.throws(() => {
+  Buffer.alloc(0x1000, 'This is not correctly encoded', 'hex');
+}, {
+  code: 'ERR_INVALID_ARG_VALUE',
+  name: 'TypeError',
+  message: "Failed to decode value",
+});
+
+assert.throws(() => {
+  Buffer.alloc(0x1000, 'c', 'hex');
+}, {
+  code: 'ERR_INVALID_ARG_VALUE',
+  name: 'TypeError',
+  message: "Failed to decode value",
+});
+
+assert.throws(() => {
+  Buffer.alloc(1, Buffer.alloc(0));
+}, {
+  code: 'ERR_INVALID_ARG_VALUE',
+  name: 'TypeError',
+  message: "Buffer cannot be empty",
+});
+
+assert.throws(() => {
+  Buffer.alloc(40, 'x', 20);
+}, {
+  code: 'ERR_INVALID_ARG_TYPE',
+  name: 'TypeError',
+  message: `The "encoding" argument must be of type string. Received type number (20)`,
+});
diff --git a/test/js/node/test/parallel/test-buffer-arraybuffer.js b/test/js/node/test/parallel/test-buffer-arraybuffer.js
new file mode 100644
index 00000000000000..de1b0647889542
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-arraybuffer.js
@@ -0,0 +1,152 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+
+const LENGTH = 16;
+
+const ab = new ArrayBuffer(LENGTH);
+const dv = new DataView(ab);
+const ui = new Uint8Array(ab);
+const buf = Buffer.from(ab);
+
+
+assert.ok(buf instanceof Buffer);
+assert.strictEqual(buf.parent, buf.buffer);
+assert.strictEqual(buf.buffer, ab);
+assert.strictEqual(buf.length, ab.byteLength);
+
+
+buf.fill(0xC);
+for (let i = 0; i < LENGTH; i++) {
+  assert.strictEqual(ui[i], 0xC);
+  ui[i] = 0xF;
+  assert.strictEqual(buf[i], 0xF);
+}
+
+buf.writeUInt32LE(0xF00, 0);
+buf.writeUInt32BE(0xB47, 4);
+buf.writeDoubleLE(3.1415, 8);
+
+assert.strictEqual(dv.getUint32(0, true), 0xF00);
+assert.strictEqual(dv.getUint32(4), 0xB47);
+assert.strictEqual(dv.getFloat64(8, true), 3.1415);
+
+
+// Now test protecting users from doing stupid things
+
+assert.throws(function() {
+  function AB() { }
+  Object.setPrototypeOf(AB, ArrayBuffer);
+  Object.setPrototypeOf(AB.prototype, ArrayBuffer.prototype);
+  Buffer.from(new AB());
+}, {
+  code: 'ERR_INVALID_ARG_TYPE',
+  name: 'TypeError',
+  message: 'The first argument must be of type string, ' +
+           'Buffer, ArrayBuffer, Array, or Array-like Object. Received ' +
+           'an instance of AB'
+});
+
+// Test the byteOffset and length arguments
+{
+  const ab = new Uint8Array(5);
+  ab[0] = 1;
+  ab[1] = 2;
+  ab[2] = 3;
+  ab[3] = 4;
+  ab[4] = 5;
+  const buf = Buffer.from(ab.buffer, 1, 3);
+  assert.strictEqual(buf.length, 3);
+  assert.strictEqual(buf[0], 2);
+  assert.strictEqual(buf[1], 3);
+  assert.strictEqual(buf[2], 4);
+  buf[0] = 9;
+  assert.strictEqual(ab[1], 9);
+
+  assert.throws(() => Buffer.from(ab.buffer, 6), {
+    code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+    name: 'RangeError',
+    message: '"offset" is outside of buffer bounds'
+  });
+  assert.throws(() => Buffer.from(ab.buffer, 3, 6), {
+    code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+    name: 'RangeError',
+    message: '"length" is outside of buffer bounds'
+  });
+}
+
+// Test the deprecated Buffer() version also
+{
+  const ab = new Uint8Array(5);
+  ab[0] = 1;
+  ab[1] = 2;
+  ab[2] = 3;
+  ab[3] = 4;
+  ab[4] = 5;
+  const buf = Buffer(ab.buffer, 1, 3);
+  assert.strictEqual(buf.length, 3);
+  assert.strictEqual(buf[0], 2);
+  assert.strictEqual(buf[1], 3);
+  assert.strictEqual(buf[2], 4);
+  buf[0] = 9;
+  assert.strictEqual(ab[1], 9);
+
+  assert.throws(() => Buffer(ab.buffer, 6), {
+    code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+    name: 'RangeError',
+    message: '"offset" is outside of buffer bounds'
+  });
+  assert.throws(() => Buffer(ab.buffer, 3, 6), {
+    code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+    name: 'RangeError',
+    message: '"length" is outside of buffer bounds'
+  });
+}
+
+{
+  // If byteOffset is not numeric, it defaults to 0.
+  const ab = new ArrayBuffer(10);
+  const expected = Buffer.from(ab, 0);
+  assert.deepStrictEqual(Buffer.from(ab, 'fhqwhgads'), expected);
+  assert.deepStrictEqual(Buffer.from(ab, NaN), expected);
+  assert.deepStrictEqual(Buffer.from(ab, {}), expected);
+  assert.deepStrictEqual(Buffer.from(ab, []), expected);
+
+  // If byteOffset can be converted to a number, it will be.
+  assert.deepStrictEqual(Buffer.from(ab, [1]), Buffer.from(ab, 1));
+
+  // If byteOffset is Infinity, throw.
+  assert.throws(() => {
+    Buffer.from(ab, Infinity);
+  }, {
+    code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+    name: 'RangeError',
+    message: '"offset" is outside of buffer bounds'
+  });
+}
+
+{
+  // If length is not numeric, it defaults to 0.
+  const ab = new ArrayBuffer(10);
+  const expected = Buffer.from(ab, 0, 0);
+  assert.deepStrictEqual(Buffer.from(ab, 0, 'fhqwhgads'), expected);
+  assert.deepStrictEqual(Buffer.from(ab, 0, NaN), expected);
+  assert.deepStrictEqual(Buffer.from(ab, 0, {}), expected);
+  assert.deepStrictEqual(Buffer.from(ab, 0, []), expected);
+
+  // If length can be converted to a number, it will be.
+  assert.deepStrictEqual(Buffer.from(ab, 0, [1]), Buffer.from(ab, 0, 1));
+
+  // If length is Infinity, throw.
+  assert.throws(() => {
+    Buffer.from(ab, 0, Infinity);
+  }, {
+    code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+    name: 'RangeError',
+    message: '"length" is outside of buffer bounds'
+  });
+}
+
+// Test an array like entry with the length set to NaN.
+assert.deepStrictEqual(Buffer.from({ length: NaN }), Buffer.alloc(0));
diff --git a/test/js/node/test/parallel/test-buffer-backing-arraybuffer.js b/test/js/node/test/parallel/test-buffer-backing-arraybuffer.js
new file mode 100644
index 00000000000000..35eb41819fdd0b
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-backing-arraybuffer.js
@@ -0,0 +1,38 @@
+// Flags: --expose-internals
+'use strict';
+const common = require('../common');
+if (true) return; // TODO: BUN
+const assert = require('assert');
+const { internalBinding } = require('internal/test/binding');
+const { arrayBufferViewHasBuffer } = internalBinding('util');
+
+const tests = [
+  { length: 0, expectOnHeap: true },
+  { length: 48, expectOnHeap: true },
+  { length: 96, expectOnHeap: false },
+  { length: 1024, expectOnHeap: false },
+];
+
+for (const { length, expectOnHeap } of tests) {
+  const arrays = [
+    new Uint8Array(length),
+    new Uint16Array(length / 2),
+    new Uint32Array(length / 4),
+    new Float32Array(length / 4),
+    new Float64Array(length / 8),
+    Buffer.alloc(length),
+    Buffer.allocUnsafeSlow(length),
+    // Buffer.allocUnsafe() is missing because it may use pooled allocations.
+  ];
+
+  for (const array of arrays) {
+    const isOnHeap = !arrayBufferViewHasBuffer(array);
+    assert.strictEqual(isOnHeap, expectOnHeap,
+                       `mismatch: ${isOnHeap} vs ${expectOnHeap} ` +
+                       `for ${array.constructor.name}, length = ${length}`);
+
+    // Consistency check: Accessing .buffer should create it.
+    array.buffer; // eslint-disable-line no-unused-expressions
+    assert(arrayBufferViewHasBuffer(array));
+  }
+}
diff --git a/test/js/node/test/parallel/test-buffer-badhex.js b/test/js/node/test/parallel/test-buffer-badhex.js
new file mode 100644
index 00000000000000..61086659fa7b6e
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-badhex.js
@@ -0,0 +1,48 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+// Test hex strings and bad hex strings
+{
+  const buf = Buffer.alloc(4);
+  assert.strictEqual(buf.length, 4);
+  assert.deepStrictEqual(buf, Buffer.from([0, 0, 0, 0]));
+  assert.strictEqual(buf.write('abcdxx', 0, 'hex'), 2);
+  assert.deepStrictEqual(buf, Buffer.from([0xab, 0xcd, 0x00, 0x00]));
+  assert.strictEqual(buf.toString('hex'), 'abcd0000');
+  assert.strictEqual(buf.write('abcdef01', 0, 'hex'), 4);
+  assert.deepStrictEqual(buf, Buffer.from([0xab, 0xcd, 0xef, 0x01]));
+  assert.strictEqual(buf.toString('hex'), 'abcdef01');
+
+  const copy = Buffer.from(buf.toString('hex'), 'hex');
+  assert.strictEqual(buf.toString('hex'), copy.toString('hex'));
+}
+
+{
+  const buf = Buffer.alloc(5);
+  assert.strictEqual(buf.write('abcdxx', 1, 'hex'), 2);
+  assert.strictEqual(buf.toString('hex'), '00abcd0000');
+}
+
+{
+  const buf = Buffer.alloc(4);
+  assert.deepStrictEqual(buf, Buffer.from([0, 0, 0, 0]));
+  assert.strictEqual(buf.write('xxabcd', 0, 'hex'), 0);
+  assert.deepStrictEqual(buf, Buffer.from([0, 0, 0, 0]));
+  assert.strictEqual(buf.write('xxab', 1, 'hex'), 0);
+  assert.deepStrictEqual(buf, Buffer.from([0, 0, 0, 0]));
+  assert.strictEqual(buf.write('cdxxab', 0, 'hex'), 1);
+  assert.deepStrictEqual(buf, Buffer.from([0xcd, 0, 0, 0]));
+}
+
+{
+  const buf = Buffer.alloc(256);
+  for (let i = 0; i < 256; i++)
+    buf[i] = i;
+
+  const hex = buf.toString('hex');
+  assert.deepStrictEqual(Buffer.from(hex, 'hex'), buf);
+
+  const badHex = `${hex.slice(0, 256)}xx${hex.slice(256, 510)}`;
+  assert.deepStrictEqual(Buffer.from(badHex, 'hex'), buf.slice(0, 128));
+}
diff --git a/test/js/node/test/parallel/test-buffer-bigint64.js b/test/js/node/test/parallel/test-buffer-bigint64.js
new file mode 100644
index 00000000000000..3b7a28b99e43c8
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-bigint64.js
@@ -0,0 +1,55 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+const buf = Buffer.allocUnsafe(8);
+
+['LE', 'BE'].forEach(function(endianness) {
+  // Should allow simple BigInts to be written and read
+  let val = 123456789n;
+  buf[`writeBigInt64${endianness}`](val, 0);
+  let rtn = buf[`readBigInt64${endianness}`](0);
+  assert.strictEqual(val, rtn);
+
+  // Should allow INT64_MAX to be written and read
+  val = 0x7fffffffffffffffn;
+  buf[`writeBigInt64${endianness}`](val, 0);
+  rtn = buf[`readBigInt64${endianness}`](0);
+  assert.strictEqual(val, rtn);
+
+  // Should read and write a negative signed 64-bit integer
+  val = -123456789n;
+  buf[`writeBigInt64${endianness}`](val, 0);
+  assert.strictEqual(val, buf[`readBigInt64${endianness}`](0));
+
+  // Should read and write an unsigned 64-bit integer
+  val = 123456789n;
+  buf[`writeBigUInt64${endianness}`](val, 0);
+  assert.strictEqual(val, buf[`readBigUInt64${endianness}`](0));
+
+  // Should throw a RangeError upon INT64_MAX+1 being written
+  assert.throws(function() {
+    const val = 0x8000000000000000n;
+    buf[`writeBigInt64${endianness}`](val, 0);
+  }, RangeError);
+
+  // Should throw a RangeError upon UINT64_MAX+1 being written
+  assert.throws(function() {
+    const val = 0x10000000000000000n;
+    buf[`writeBigUInt64${endianness}`](val, 0);
+  }, {
+    code: 'ERR_OUT_OF_RANGE',
+    message: 'The value of "value" is out of range. It must be ' +
+      '>= 0n and < 2n ** 64n. Received 18446744073709551616n'
+  });
+
+  // Should throw a TypeError upon invalid input
+  assert.throws(function() {
+    buf[`writeBigInt64${endianness}`]('bad', 0);
+  }, TypeError);
+
+  // Should throw a TypeError upon invalid input
+  assert.throws(function() {
+    buf[`writeBigUInt64${endianness}`]('bad', 0);
+  }, TypeError);
+});
diff --git a/test/js/node/test/parallel/test-buffer-bytelength.js b/test/js/node/test/parallel/test-buffer-bytelength.js
new file mode 100644
index 00000000000000..95d54d425bc252
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-bytelength.js
@@ -0,0 +1,132 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const SlowBuffer = require('buffer').SlowBuffer;
+const vm = require('vm');
+
+[
+  [32, 'latin1'],
+  [NaN, 'utf8'],
+  [{}, 'latin1'],
+  [],
+].forEach((args) => {
+  assert.throws(
+    () => Buffer.byteLength(...args),
+    {
+      code: 'ERR_INVALID_ARG_TYPE',
+      name: 'TypeError',
+      message: 'The "string" argument must be of type string or an instance ' +
+               'of Buffer or ArrayBuffer.' +
+               common.invalidArgTypeHelper(args[0])
+    }
+  );
+});
+
+assert(ArrayBuffer.isView(new Buffer(10)));
+assert(ArrayBuffer.isView(new SlowBuffer(10)));
+assert(ArrayBuffer.isView(Buffer.alloc(10)));
+assert(ArrayBuffer.isView(Buffer.allocUnsafe(10)));
+assert(ArrayBuffer.isView(Buffer.allocUnsafeSlow(10)));
+assert(ArrayBuffer.isView(Buffer.from('')));
+
+// buffer
+const incomplete = Buffer.from([0xe4, 0xb8, 0xad, 0xe6, 0x96]);
+assert.strictEqual(Buffer.byteLength(incomplete), 5);
+const ascii = Buffer.from('abc');
+assert.strictEqual(Buffer.byteLength(ascii), 3);
+
+// ArrayBuffer
+const buffer = new ArrayBuffer(8);
+assert.strictEqual(Buffer.byteLength(buffer), 8);
+
+// TypedArray
+const int8 = new Int8Array(8);
+assert.strictEqual(Buffer.byteLength(int8), 8);
+const uint8 = new Uint8Array(8);
+assert.strictEqual(Buffer.byteLength(uint8), 8);
+const uintc8 = new Uint8ClampedArray(2);
+assert.strictEqual(Buffer.byteLength(uintc8), 2);
+const int16 = new Int16Array(8);
+assert.strictEqual(Buffer.byteLength(int16), 16);
+const uint16 = new Uint16Array(8);
+assert.strictEqual(Buffer.byteLength(uint16), 16);
+const int32 = new Int32Array(8);
+assert.strictEqual(Buffer.byteLength(int32), 32);
+const uint32 = new Uint32Array(8);
+assert.strictEqual(Buffer.byteLength(uint32), 32);
+const float32 = new Float32Array(8);
+assert.strictEqual(Buffer.byteLength(float32), 32);
+const float64 = new Float64Array(8);
+assert.strictEqual(Buffer.byteLength(float64), 64);
+
+// DataView
+const dv = new DataView(new ArrayBuffer(2));
+assert.strictEqual(Buffer.byteLength(dv), 2);
+
+// Special case: zero length string
+assert.strictEqual(Buffer.byteLength('', 'ascii'), 0);
+assert.strictEqual(Buffer.byteLength('', 'HeX'), 0);
+
+// utf8
+assert.strictEqual(Buffer.byteLength('∑éllö wørl∂!', 'utf-8'), 19);
+assert.strictEqual(Buffer.byteLength('κλμνξο', 'utf8'), 12);
+assert.strictEqual(Buffer.byteLength('挵挶挷挸挹', 'utf-8'), 15);
+assert.strictEqual(Buffer.byteLength('𠝹𠱓𠱸', 'UTF8'), 12);
+// Without an encoding, utf8 should be assumed
+assert.strictEqual(Buffer.byteLength('hey there'), 9);
+assert.strictEqual(Buffer.byteLength('𠱸挶νξ#xx :)'), 17);
+assert.strictEqual(Buffer.byteLength('hello world', ''), 11);
+// It should also be assumed with unrecognized encoding
+assert.strictEqual(Buffer.byteLength('hello world', 'abc'), 11);
+assert.strictEqual(Buffer.byteLength('ßœ∑≈', 'unkn0wn enc0ding'), 10);
+
+// base64
+assert.strictEqual(Buffer.byteLength('aGVsbG8gd29ybGQ=', 'base64'), 11);
+assert.strictEqual(Buffer.byteLength('aGVsbG8gd29ybGQ=', 'BASE64'), 11);
+assert.strictEqual(Buffer.byteLength('bm9kZS5qcyByb2NrcyE=', 'base64'), 14);
+assert.strictEqual(Buffer.byteLength('aGkk', 'base64'), 3);
+assert.strictEqual(
+  Buffer.byteLength('bHNrZGZsa3NqZmtsc2xrZmFqc2RsZmtqcw==', 'base64'), 25
+);
+// base64url
+assert.strictEqual(Buffer.byteLength('aGVsbG8gd29ybGQ', 'base64url'), 11);
+assert.strictEqual(Buffer.byteLength('aGVsbG8gd29ybGQ', 'BASE64URL'), 11);
+assert.strictEqual(Buffer.byteLength('bm9kZS5qcyByb2NrcyE', 'base64url'), 14);
+assert.strictEqual(Buffer.byteLength('aGkk', 'base64url'), 3);
+assert.strictEqual(
+  Buffer.byteLength('bHNrZGZsa3NqZmtsc2xrZmFqc2RsZmtqcw', 'base64url'), 25
+);
+// special padding
+assert.strictEqual(Buffer.byteLength('aaa=', 'base64'), 2);
+assert.strictEqual(Buffer.byteLength('aaaa==', 'base64'), 3);
+assert.strictEqual(Buffer.byteLength('aaa=', 'base64url'), 2);
+assert.strictEqual(Buffer.byteLength('aaaa==', 'base64url'), 3);
+
+assert.strictEqual(Buffer.byteLength('Il était tué'), 14);
+assert.strictEqual(Buffer.byteLength('Il était tué', 'utf8'), 14);
+
+['ascii', 'latin1', 'binary']
+  .reduce((es, e) => es.concat(e, e.toUpperCase()), [])
+  .forEach((encoding) => {
+    assert.strictEqual(Buffer.byteLength('Il était tué', encoding), 12);
+  });
+
+['ucs2', 'ucs-2', 'utf16le', 'utf-16le']
+  .reduce((es, e) => es.concat(e, e.toUpperCase()), [])
+  .forEach((encoding) => {
+    assert.strictEqual(Buffer.byteLength('Il était tué', encoding), 24);
+  });
+
+// Test that ArrayBuffer from a different context is detected correctly
+const arrayBuf = vm.runInNewContext('new ArrayBuffer()');
+assert.strictEqual(Buffer.byteLength(arrayBuf), 0);
+
+// Verify that invalid encodings are treated as utf8
+for (let i = 1; i < 10; i++) {
+  const encoding = String(i).repeat(i);
+
+  assert.ok(!Buffer.isEncoding(encoding));
+  assert.strictEqual(Buffer.byteLength('foo', encoding),
+                     Buffer.byteLength('foo', 'utf8'));
+}
diff --git a/test/js/node/test/parallel/test-buffer-compare.js b/test/js/node/test/parallel/test-buffer-compare.js
new file mode 100644
index 00000000000000..a0bddb5ab5d0f0
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-compare.js
@@ -0,0 +1,47 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+
+const b = Buffer.alloc(1, 'a');
+const c = Buffer.alloc(1, 'c');
+const d = Buffer.alloc(2, 'aa');
+const e = new Uint8Array([ 0x61, 0x61 ]); // ASCII 'aa', same as d
+
+assert.strictEqual(b.compare(c), -1);
+assert.strictEqual(c.compare(d), 1);
+assert.strictEqual(d.compare(b), 1);
+assert.strictEqual(d.compare(e), 0);
+assert.strictEqual(b.compare(d), -1);
+assert.strictEqual(b.compare(b), 0);
+
+assert.strictEqual(Buffer.compare(b, c), -1);
+assert.strictEqual(Buffer.compare(c, d), 1);
+assert.strictEqual(Buffer.compare(d, b), 1);
+assert.strictEqual(Buffer.compare(b, d), -1);
+assert.strictEqual(Buffer.compare(c, c), 0);
+assert.strictEqual(Buffer.compare(e, e), 0);
+assert.strictEqual(Buffer.compare(d, e), 0);
+assert.strictEqual(Buffer.compare(d, b), 1);
+
+assert.strictEqual(Buffer.compare(Buffer.alloc(0), Buffer.alloc(0)), 0);
+assert.strictEqual(Buffer.compare(Buffer.alloc(0), Buffer.alloc(1)), -1);
+assert.strictEqual(Buffer.compare(Buffer.alloc(1), Buffer.alloc(0)), 1);
+
+assert.throws(() => Buffer.compare(Buffer.alloc(1), 'abc'), {
+  code: 'ERR_INVALID_ARG_TYPE',
+  message: 'The "buf2" argument must be an instance of Buffer or Uint8Array. ' +
+           'Received type string ("abc")'
+});
+assert.throws(() => Buffer.compare('abc', Buffer.alloc(1)), {
+  code: 'ERR_INVALID_ARG_TYPE',
+  message: 'The "buf1" argument must be an instance of Buffer or Uint8Array. ' +
+           'Received type string ("abc")'
+});
+
+assert.throws(() => Buffer.alloc(1).compare('abc'), {
+  code: 'ERR_INVALID_ARG_TYPE',
+  name: 'TypeError',
+  message: 'The "target" argument must be an instance of ' +
+           'Buffer or Uint8Array. Received type string ("abc")'
+});
diff --git a/test/js/node/test/parallel/test-buffer-concat.js b/test/js/node/test/parallel/test-buffer-concat.js
new file mode 100644
index 00000000000000..2e7541fb58b063
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-concat.js
@@ -0,0 +1,100 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+const zero = [];
+const one = [ Buffer.from('asdf') ];
+const long = [];
+for (let i = 0; i < 10; i++) long.push(Buffer.from('asdf'));
+
+const flatZero = Buffer.concat(zero);
+const flatOne = Buffer.concat(one);
+const flatLong = Buffer.concat(long);
+const flatLongLen = Buffer.concat(long, 40);
+
+assert.strictEqual(flatZero.length, 0);
+assert.strictEqual(flatOne.toString(), 'asdf');
+
+const check = 'asdf'.repeat(10);
+
+// A special case where concat used to return the first item,
+// if the length is one. This check is to make sure that we don't do that.
+assert.notStrictEqual(flatOne, one[0]);
+assert.strictEqual(flatLong.toString(), check);
+assert.strictEqual(flatLongLen.toString(), check);
+
+[undefined, null, Buffer.from('hello')].forEach((value) => {
+  assert.throws(() => {
+    Buffer.concat(value);
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE',
+    message: 'The "list" argument must be an instance of Array.' +
+             `${common.invalidArgTypeHelper(value)}`
+  });
+});
+
+[[42], ['hello', Buffer.from('world')]].forEach((value) => {
+  assert.throws(() => {
+    Buffer.concat(value);
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE',
+    message: 'The "list[0]" argument must be an instance of Buffer ' +
+             `or Uint8Array.${common.invalidArgTypeHelper(value[0])}`
+  });
+});
+
+assert.throws(() => {
+  Buffer.concat([Buffer.from('hello'), 3]);
+}, {
+  code: 'ERR_INVALID_ARG_TYPE',
+  message: 'The "list[1]" argument must be an instance of Buffer ' +
+           'or Uint8Array. Received type number (3)'
+});
+
+// eslint-disable-next-line node-core/crypto-check
+const random10 = common.hasCrypto ?
+  require('crypto').randomBytes(10) :
+  Buffer.alloc(10, 1);
+const empty = Buffer.alloc(0);
+
+assert.notDeepStrictEqual(random10, empty);
+assert.notDeepStrictEqual(random10, Buffer.alloc(10));
+
+assert.deepStrictEqual(Buffer.concat([], 100), empty);
+assert.deepStrictEqual(Buffer.concat([random10], 0), empty);
+assert.deepStrictEqual(Buffer.concat([random10], 10), random10);
+assert.deepStrictEqual(Buffer.concat([random10, random10], 10), random10);
+assert.deepStrictEqual(Buffer.concat([empty, random10]), random10);
+assert.deepStrictEqual(Buffer.concat([random10, empty, empty]), random10);
+
+// The tail should be zero-filled
+assert.deepStrictEqual(Buffer.concat([empty], 100), Buffer.alloc(100));
+assert.deepStrictEqual(Buffer.concat([empty], 4096), Buffer.alloc(4096));
+assert.deepStrictEqual(
+  Buffer.concat([random10], 40),
+  Buffer.concat([random10, Buffer.alloc(30)]));
+
+assert.deepStrictEqual(Buffer.concat([new Uint8Array([0x41, 0x42]),
+                                      new Uint8Array([0x43, 0x44])]),
+                       Buffer.from('ABCD'));
diff --git a/test/js/node/test/parallel/test-buffer-constants.js b/test/js/node/test/parallel/test-buffer-constants.js
new file mode 100644
index 00000000000000..458d9a39c5364f
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-constants.js
@@ -0,0 +1,17 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+const { kMaxLength, kStringMaxLength } = require('buffer');
+const { MAX_LENGTH, MAX_STRING_LENGTH } = require('buffer').constants;
+
+assert.strictEqual(typeof MAX_LENGTH, 'number');
+assert.strictEqual(typeof MAX_STRING_LENGTH, 'number');
+assert(MAX_STRING_LENGTH <= MAX_LENGTH);
+assert.throws(() => ' '.repeat(MAX_STRING_LENGTH + 1), /^RangeError: Out of memory$/);
+
+' '.repeat(MAX_STRING_LENGTH); // Should not throw.
+
+// Legacy values match:
+assert.strictEqual(kMaxLength, MAX_LENGTH);
+assert.strictEqual(kStringMaxLength, MAX_STRING_LENGTH);
diff --git a/test/js/node/test/parallel/test-buffer-copy.js b/test/js/node/test/parallel/test-buffer-copy.js
new file mode 100644
index 00000000000000..16a638a51181e6
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-copy.js
@@ -0,0 +1,237 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+
+const b = Buffer.allocUnsafe(1024);
+const c = Buffer.allocUnsafe(512);
+
+let cntr = 0;
+
+{
+  // copy 512 bytes, from 0 to 512.
+  b.fill(++cntr);
+  c.fill(++cntr);
+  const copied = b.copy(c, 0, 0, 512);
+  assert.strictEqual(copied, 512);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(c[i], b[i]);
+  }
+}
+
+{
+  // Current behavior is to coerce values to integers.
+  b.fill(++cntr);
+  c.fill(++cntr);
+  const copied = b.copy(c, '0', '0', '512');
+  assert.strictEqual(copied, 512);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(c[i], b[i]);
+  }
+}
+
+{
+  // Floats will be converted to integers via `Math.floor`
+  b.fill(++cntr);
+  c.fill(++cntr);
+  const copied = b.copy(c, 0, 0, 512.5);
+  assert.strictEqual(copied, 512);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(c[i], b[i]);
+  }
+}
+
+{
+  // Copy c into b, without specifying sourceEnd
+  b.fill(++cntr);
+  c.fill(++cntr);
+  const copied = c.copy(b, 0, 0);
+  assert.strictEqual(copied, c.length);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(b[i], c[i]);
+  }
+}
+
+{
+  // Copy c into b, without specifying sourceStart
+  b.fill(++cntr);
+  c.fill(++cntr);
+  const copied = c.copy(b, 0);
+  assert.strictEqual(copied, c.length);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(b[i], c[i]);
+  }
+}
+
+{
+  // Copied source range greater than source length
+  b.fill(++cntr);
+  c.fill(++cntr);
+  const copied = c.copy(b, 0, 0, c.length + 1);
+  assert.strictEqual(copied, c.length);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(b[i], c[i]);
+  }
+}
+
+{
+  // Copy longer buffer b to shorter c without targetStart
+  b.fill(++cntr);
+  c.fill(++cntr);
+  const copied = b.copy(c);
+  assert.strictEqual(copied, c.length);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(c[i], b[i]);
+  }
+}
+
+{
+  // Copy starting near end of b to c
+  b.fill(++cntr);
+  c.fill(++cntr);
+  const copied = b.copy(c, 0, b.length - Math.floor(c.length / 2));
+  assert.strictEqual(copied, Math.floor(c.length / 2));
+  for (let i = 0; i < Math.floor(c.length / 2); i++) {
+    assert.strictEqual(c[i], b[b.length - Math.floor(c.length / 2) + i]);
+  }
+  for (let i = Math.floor(c.length / 2) + 1; i < c.length; i++) {
+    assert.strictEqual(c[c.length - 1], c[i]);
+  }
+}
+
+{
+  // Try to copy 513 bytes, and check we don't overrun c
+  b.fill(++cntr);
+  c.fill(++cntr);
+  const copied = b.copy(c, 0, 0, 513);
+  assert.strictEqual(copied, c.length);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(c[i], b[i]);
+  }
+}
+
+{
+  // copy 768 bytes from b into b
+  b.fill(++cntr);
+  b.fill(++cntr, 256);
+  const copied = b.copy(b, 0, 256, 1024);
+  assert.strictEqual(copied, 768);
+  for (let i = 0; i < b.length; i++) {
+    assert.strictEqual(b[i], cntr);
+  }
+}
+
+// Copy string longer than buffer length (failure will segfault)
+const bb = Buffer.allocUnsafe(10);
+bb.fill('hello crazy world');
+
+
+// Try to copy from before the beginning of b. Should not throw.
+b.copy(c, 0, 100, 10);
+
+// Throw with invalid source type
+assert.throws(
+  () => Buffer.prototype.copy.call(0),
+  {
+    // code: 'ERR_INVALID_ARG_TYPE',
+    code: 'ERR_INVALID_THIS',
+    name: 'TypeError',
+  }
+);
+
+// Copy throws at negative targetStart
+assert.throws(
+  () => Buffer.allocUnsafe(5).copy(Buffer.allocUnsafe(5), -1, 0),
+  {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+    message: 'The value of "targetStart" is out of range. ' +
+             'It must be >= 0 and <= 5. Received -1'
+  }
+);
+
+// Copy throws at negative sourceStart
+assert.throws(
+  () => Buffer.allocUnsafe(5).copy(Buffer.allocUnsafe(5), 0, -1),
+  {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+  }
+);
+
+// Copy throws if sourceStart is greater than length of source
+assert.throws(
+  () => Buffer.allocUnsafe(5).copy(Buffer.allocUnsafe(5), 0, 100),
+  {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+  }
+);
+
+{
+  // Check sourceEnd resets to targetEnd if former is greater than the latter
+  b.fill(++cntr);
+  c.fill(++cntr);
+  b.copy(c, 0, 0, 1025);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(c[i], b[i]);
+  }
+}
+
+// Throw with negative sourceEnd
+assert.throws(
+  () => b.copy(c, 0, 0, -1),
+  {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+    message: 'The value of "sourceEnd" is out of range. ' +
+             'It must be >= 0 and <= 1024. Received -1'
+  }
+);
+
+// When sourceStart is greater than sourceEnd, zero copied
+assert.strictEqual(b.copy(c, 0, 100, 10), 0);
+
+// When targetStart > targetLength, zero copied
+assert.strictEqual(b.copy(c, 512, 0, 10), 0);
+
+// Test that the `target` can be a Uint8Array.
+{
+  const d = new Uint8Array(c);
+  // copy 512 bytes, from 0 to 512.
+  b.fill(++cntr);
+  d.fill(++cntr);
+  const copied = b.copy(d, 0, 0, 512);
+  assert.strictEqual(copied, 512);
+  for (let i = 0; i < d.length; i++) {
+    assert.strictEqual(d[i], b[i]);
+  }
+}
+
+// Test that the source can be a Uint8Array, too.
+{
+  const e = new Uint8Array(b);
+  // copy 512 bytes, from 0 to 512.
+  e.fill(++cntr);
+  c.fill(++cntr);
+  const copied = Buffer.prototype.copy.call(e, c, 0, 0, 512);
+  assert.strictEqual(copied, 512);
+  for (let i = 0; i < c.length; i++) {
+    assert.strictEqual(c[i], e[i]);
+  }
+}
+
+// https://github.com/nodejs/node/issues/23668: Do not crash for invalid input.
+c.fill('c');
+b.copy(c, 'not a valid offset');
+// Make sure this acted like a regular copy with `0` offset.
+assert.deepStrictEqual(c, b.slice(0, c.length));
+
+{
+  c.fill('C');
+  assert.throws(() => {
+    b.copy(c, { [Symbol.toPrimitive]() { throw new Error('foo'); } });
+  }, /foo/);
+  // No copying took place:
+  assert.deepStrictEqual(c.toString(), 'C'.repeat(c.length));
+}
diff --git a/test/js/node/test/parallel/test-buffer-equals.js b/test/js/node/test/parallel/test-buffer-equals.js
new file mode 100644
index 00000000000000..62b1289b3466d1
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-equals.js
@@ -0,0 +1,25 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+
+const b = Buffer.from('abcdf');
+const c = Buffer.from('abcdf');
+const d = Buffer.from('abcde');
+const e = Buffer.from('abcdef');
+
+assert.ok(b.equals(c));
+assert.ok(!c.equals(d));
+assert.ok(!d.equals(e));
+assert.ok(d.equals(d));
+assert.ok(d.equals(new Uint8Array([0x61, 0x62, 0x63, 0x64, 0x65])));
+
+assert.throws(
+  () => Buffer.alloc(1).equals('abc'),
+  {
+    code: 'ERR_INVALID_ARG_TYPE',
+    name: 'TypeError',
+    message: 'The "otherBuffer" argument must be an instance of ' +
+             'Buffer or Uint8Array. Received type string ("abc")'
+  }
+);
diff --git a/test/js/node/test/parallel/test-buffer-fill.js b/test/js/node/test/parallel/test-buffer-fill.js
new file mode 100644
index 00000000000000..32291d3123bc48
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-fill.js
@@ -0,0 +1,429 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const SIZE = 28;
+
+const buf1 = Buffer.allocUnsafe(SIZE);
+const buf2 = Buffer.allocUnsafe(SIZE);
+
+// Default encoding
+testBufs('abc');
+testBufs('\u0222aa');
+testBufs('a\u0234b\u0235c\u0236');
+testBufs('abc', 4);
+testBufs('abc', 5);
+testBufs('abc', SIZE);
+testBufs('\u0222aa', 2);
+testBufs('\u0222aa', 8);
+testBufs('a\u0234b\u0235c\u0236', 4);
+testBufs('a\u0234b\u0235c\u0236', 12);
+testBufs('abc', 4, 1);
+testBufs('abc', 5, 1);
+testBufs('\u0222aa', 8, 1);
+testBufs('a\u0234b\u0235c\u0236', 4, 1);
+testBufs('a\u0234b\u0235c\u0236', 12, 1);
+
+// UTF8
+testBufs('abc', 'utf8');
+testBufs('\u0222aa', 'utf8');
+testBufs('a\u0234b\u0235c\u0236', 'utf8');
+testBufs('abc', 4, 'utf8');
+testBufs('abc', 5, 'utf8');
+testBufs('abc', SIZE, 'utf8');
+testBufs('\u0222aa', 2, 'utf8');
+testBufs('\u0222aa', 8, 'utf8');
+testBufs('a\u0234b\u0235c\u0236', 4, 'utf8');
+testBufs('a\u0234b\u0235c\u0236', 12, 'utf8');
+testBufs('abc', 4, 1, 'utf8');
+testBufs('abc', 5, 1, 'utf8');
+testBufs('\u0222aa', 8, 1, 'utf8');
+testBufs('a\u0234b\u0235c\u0236', 4, 1, 'utf8');
+testBufs('a\u0234b\u0235c\u0236', 12, 1, 'utf8');
+assert.strictEqual(Buffer.allocUnsafe(1).fill(0).fill('\u0222')[0], 0xc8);
+
+// BINARY
+testBufs('abc', 'binary');
+testBufs('\u0222aa', 'binary');
+testBufs('a\u0234b\u0235c\u0236', 'binary');
+testBufs('abc', 4, 'binary');
+testBufs('abc', 5, 'binary');
+testBufs('abc', SIZE, 'binary');
+testBufs('\u0222aa', 2, 'binary');
+testBufs('\u0222aa', 8, 'binary');
+testBufs('a\u0234b\u0235c\u0236', 4, 'binary');
+testBufs('a\u0234b\u0235c\u0236', 12, 'binary');
+testBufs('abc', 4, 1, 'binary');
+testBufs('abc', 5, 1, 'binary');
+testBufs('\u0222aa', 8, 1, 'binary');
+testBufs('a\u0234b\u0235c\u0236', 4, 1, 'binary');
+testBufs('a\u0234b\u0235c\u0236', 12, 1, 'binary');
+
+// LATIN1
+testBufs('abc', 'latin1');
+testBufs('\u0222aa', 'latin1');
+testBufs('a\u0234b\u0235c\u0236', 'latin1');
+testBufs('abc', 4, 'latin1');
+testBufs('abc', 5, 'latin1');
+testBufs('abc', SIZE, 'latin1');
+testBufs('\u0222aa', 2, 'latin1');
+testBufs('\u0222aa', 8, 'latin1');
+testBufs('a\u0234b\u0235c\u0236', 4, 'latin1');
+testBufs('a\u0234b\u0235c\u0236', 12, 'latin1');
+testBufs('abc', 4, 1, 'latin1');
+testBufs('abc', 5, 1, 'latin1');
+testBufs('\u0222aa', 8, 1, 'latin1');
+testBufs('a\u0234b\u0235c\u0236', 4, 1, 'latin1');
+testBufs('a\u0234b\u0235c\u0236', 12, 1, 'latin1');
+
+// UCS2
+testBufs('abc', 'ucs2');
+testBufs('\u0222aa', 'ucs2');
+testBufs('a\u0234b\u0235c\u0236', 'ucs2');
+testBufs('abc', 4, 'ucs2');
+testBufs('abc', SIZE, 'ucs2');
+testBufs('\u0222aa', 2, 'ucs2');
+testBufs('\u0222aa', 8, 'ucs2');
+testBufs('a\u0234b\u0235c\u0236', 4, 'ucs2');
+testBufs('a\u0234b\u0235c\u0236', 12, 'ucs2');
+testBufs('abc', 4, 1, 'ucs2');
+testBufs('abc', 5, 1, 'ucs2');
+testBufs('\u0222aa', 8, 1, 'ucs2');
+testBufs('a\u0234b\u0235c\u0236', 4, 1, 'ucs2');
+testBufs('a\u0234b\u0235c\u0236', 12, 1, 'ucs2');
+assert.strictEqual(Buffer.allocUnsafe(1).fill('\u0222', 'ucs2')[0], 0x22);
+
+// HEX
+testBufs('616263', 'hex');
+testBufs('c8a26161', 'hex');
+testBufs('61c8b462c8b563c8b6', 'hex');
+testBufs('616263', 4, 'hex');
+testBufs('616263', 5, 'hex');
+testBufs('616263', SIZE, 'hex');
+testBufs('c8a26161', 2, 'hex');
+testBufs('c8a26161', 8, 'hex');
+testBufs('61c8b462c8b563c8b6', 4, 'hex');
+testBufs('61c8b462c8b563c8b6', 12, 'hex');
+testBufs('616263', 4, 1, 'hex');
+testBufs('616263', 5, 1, 'hex');
+testBufs('c8a26161', 8, 1, 'hex');
+testBufs('61c8b462c8b563c8b6', 4, 1, 'hex');
+testBufs('61c8b462c8b563c8b6', 12, 1, 'hex');
+
+assert.throws(() => {
+  const buf = Buffer.allocUnsafe(SIZE);
+
+  buf.fill('yKJh', 'hex');
+}, {
+  code: 'ERR_INVALID_ARG_VALUE',
+  name: 'TypeError'
+});
+
+assert.throws(() => {
+  const buf = Buffer.allocUnsafe(SIZE);
+
+  buf.fill('\u0222', 'hex');
+}, {
+  code: 'ERR_INVALID_ARG_VALUE',
+  name: 'TypeError'
+});
+
+// BASE64
+testBufs('YWJj', 'base64');
+testBufs('yKJhYQ==', 'base64');
+testBufs('Yci0Ysi1Y8i2', 'base64');
+testBufs('YWJj', 4, 'base64');
+testBufs('YWJj', SIZE, 'base64');
+testBufs('yKJhYQ==', 2, 'base64');
+testBufs('yKJhYQ==', 8, 'base64');
+testBufs('Yci0Ysi1Y8i2', 4, 'base64');
+testBufs('Yci0Ysi1Y8i2', 12, 'base64');
+testBufs('YWJj', 4, 1, 'base64');
+testBufs('YWJj', 5, 1, 'base64');
+testBufs('yKJhYQ==', 8, 1, 'base64');
+testBufs('Yci0Ysi1Y8i2', 4, 1, 'base64');
+testBufs('Yci0Ysi1Y8i2', 12, 1, 'base64');
+
+// BASE64URL
+testBufs('YWJj', 'base64url');
+testBufs('yKJhYQ', 'base64url');
+testBufs('Yci0Ysi1Y8i2', 'base64url');
+testBufs('YWJj', 4, 'base64url');
+testBufs('YWJj', SIZE, 'base64url');
+testBufs('yKJhYQ', 2, 'base64url');
+testBufs('yKJhYQ', 8, 'base64url');
+testBufs('Yci0Ysi1Y8i2', 4, 'base64url');
+testBufs('Yci0Ysi1Y8i2', 12, 'base64url');
+testBufs('YWJj', 4, 1, 'base64url');
+testBufs('YWJj', 5, 1, 'base64url');
+testBufs('yKJhYQ', 8, 1, 'base64url');
+testBufs('Yci0Ysi1Y8i2', 4, 1, 'base64url');
+testBufs('Yci0Ysi1Y8i2', 12, 1, 'base64url');
+
+// Buffer
+function deepStrictEqualValues(buf, arr) {
+  for (const [index, value] of buf.entries()) {
+    assert.deepStrictEqual(value, arr[index]);
+  }
+}
+
+const buf2Fill = Buffer.allocUnsafe(1).fill(2);
+deepStrictEqualValues(genBuffer(4, [buf2Fill]), [2, 2, 2, 2]);
+deepStrictEqualValues(genBuffer(4, [buf2Fill, 1]), [0, 2, 2, 2]);
+deepStrictEqualValues(genBuffer(4, [buf2Fill, 1, 3]), [0, 2, 2, 0]);
+deepStrictEqualValues(genBuffer(4, [buf2Fill, 1, 1]), [0, 0, 0, 0]);
+const hexBufFill = Buffer.allocUnsafe(2).fill(0).fill('0102', 'hex');
+deepStrictEqualValues(genBuffer(4, [hexBufFill]), [1, 2, 1, 2]);
+deepStrictEqualValues(genBuffer(4, [hexBufFill, 1]), [0, 1, 2, 1]);
+deepStrictEqualValues(genBuffer(4, [hexBufFill, 1, 3]), [0, 1, 2, 0]);
+deepStrictEqualValues(genBuffer(4, [hexBufFill, 1, 1]), [0, 0, 0, 0]);
+
+// Check exceptions
+[
+  [0, -1],
+  [0, 0, buf1.length + 1],
+  ['', -1],
+  ['', 0, buf1.length + 1],
+  ['', 1, -1],
+].forEach((args) => {
+  assert.throws(
+    () => buf1.fill(...args),
+    { code: 'ERR_OUT_OF_RANGE' }
+  );
+});
+
+assert.throws(
+  () => buf1.fill('a', 0, buf1.length, 'node rocks!'),
+  {
+    code: 'ERR_UNKNOWN_ENCODING',
+    name: 'TypeError',
+    message: 'Unknown encoding: node rocks!'
+  }
+);
+
+[
+  ['a', 0, 0, NaN],
+  ['a', 0, 0, false],
+].forEach((args) => {
+  assert.throws(
+    () => buf1.fill(...args),
+    {
+      code: 'ERR_INVALID_ARG_TYPE',
+      message: 'The "encoding" argument must be of type ' +
+      `string.${common.invalidArgTypeHelper(args[3])}`
+    }
+  );
+});
+
+assert.throws(
+  () => buf1.fill('a', 0, 0, 'foo'),
+  {
+    code: 'ERR_UNKNOWN_ENCODING',
+    name: 'TypeError',
+    message: 'Unknown encoding: foo'
+  }
+);
+
+function genBuffer(size, args) {
+  const b = Buffer.allocUnsafe(size);
+  return b.fill(0).fill.apply(b, args);
+}
+
+function bufReset() {
+  buf1.fill(0);
+  buf2.fill(0);
+}
+
+// This is mostly accurate. Except write() won't write partial bytes to the
+// string while fill() blindly copies bytes into memory. To account for that an
+// error will be thrown if not all the data can be written, and the SIZE has
+// been massaged to work with the input characters.
+function writeToFill(string, offset, end, encoding) {
+  if (typeof offset === 'string') {
+    encoding = offset;
+    offset = 0;
+    end = buf2.length;
+  } else if (typeof end === 'string') {
+    encoding = end;
+    end = buf2.length;
+  } else if (end === undefined) {
+    end = buf2.length;
+  }
+
+  // Should never be reached.
+  if (offset < 0 || end > buf2.length)
+    throw new ERR_OUT_OF_RANGE();
+
+  if (end <= offset)
+    return buf2;
+
+  offset >>>= 0;
+  end >>>= 0;
+  assert(offset <= buf2.length);
+
+  // Convert "end" to "length" (which write understands).
+  const length = end - offset < 0 ? 0 : end - offset;
+
+  let wasZero = false;
+  do {
+    const written = buf2.write(string, offset, length, encoding);
+    offset += written;
+    // Safety check in case write falls into infinite loop.
+    if (written === 0) {
+      if (wasZero)
+        throw new Error('Could not write all data to Buffer');
+      else
+        wasZero = true;
+    }
+  } while (offset < buf2.length);
+
+  return buf2;
+}
+
+function testBufs(string, offset, length, encoding) {
+  bufReset();
+  buf1.fill.apply(buf1, arguments);
+  // Swap bytes on BE archs for ucs2 encoding.
+  assert.deepStrictEqual(buf1.fill.apply(buf1, arguments),
+                         writeToFill.apply(null, arguments));
+}
+
+// Make sure these throw.
+assert.throws(
+  () => Buffer.allocUnsafe(8).fill('a', -1),
+  { code: 'ERR_OUT_OF_RANGE' });
+assert.throws(
+  () => Buffer.allocUnsafe(8).fill('a', 0, 9),
+  { code: 'ERR_OUT_OF_RANGE' });
+
+// Make sure this doesn't hang indefinitely.
+Buffer.allocUnsafe(8).fill('');
+Buffer.alloc(8, '');
+
+{
+  const buf = Buffer.alloc(64, 10);
+  for (let i = 0; i < buf.length; i++)
+    assert.strictEqual(buf[i], 10);
+
+  buf.fill(11, 0, buf.length >> 1);
+  for (let i = 0; i < buf.length >> 1; i++)
+    assert.strictEqual(buf[i], 11);
+  for (let i = (buf.length >> 1) + 1; i < buf.length; i++)
+    assert.strictEqual(buf[i], 10);
+
+  buf.fill('h');
+  for (let i = 0; i < buf.length; i++)
+    assert.strictEqual(buf[i], 'h'.charCodeAt(0));
+
+  buf.fill(0);
+  for (let i = 0; i < buf.length; i++)
+    assert.strictEqual(buf[i], 0);
+
+  buf.fill(null);
+  for (let i = 0; i < buf.length; i++)
+    assert.strictEqual(buf[i], 0);
+
+  buf.fill(1, 16, 32);
+  for (let i = 0; i < 16; i++)
+    assert.strictEqual(buf[i], 0);
+  for (let i = 16; i < 32; i++)
+    assert.strictEqual(buf[i], 1);
+  for (let i = 32; i < buf.length; i++)
+    assert.strictEqual(buf[i], 0);
+}
+
+{
+  const buf = Buffer.alloc(10, 'abc');
+  assert.strictEqual(buf.toString(), 'abcabcabca');
+  buf.fill('է');
+  assert.strictEqual(buf.toString(), 'էէէէէ');
+}
+
+// Make sure "end" is properly checked, even if it's magically mangled using
+// Symbol.toPrimitive.
+{
+  assert.throws(() => {
+    const end = {
+      [Symbol.toPrimitive]() {
+        return 1;
+      }
+    };
+    Buffer.alloc(1).fill(Buffer.alloc(1), 0, end);
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE',
+    message: 'The "end" argument must be of type number. Received an ' +
+             'instance of Object'
+  });
+}
+
+// Test that bypassing 'length' won't cause an abort.
+// assert.throws(() => {
+//   const buf = Buffer.from('w00t');
+//   Object.defineProperty(buf, 'length', {
+//     value: 1337,
+//     enumerable: true
+//   });
+//   buf.fill('');
+// }, {
+//   code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+//   name: 'RangeError',
+//   message: 'Attempt to access memory outside buffer bounds'
+// });
+
+assert.deepStrictEqual(
+  Buffer.allocUnsafeSlow(16).fill('ab', 'utf16le'),
+  Buffer.from('61006200610062006100620061006200', 'hex'));
+
+assert.deepStrictEqual(
+  Buffer.allocUnsafeSlow(15).fill('ab', 'utf16le'),
+  Buffer.from('610062006100620061006200610062', 'hex'));
+
+assert.deepStrictEqual(
+  Buffer.allocUnsafeSlow(16).fill('ab', 'utf16le'),
+  Buffer.from('61006200610062006100620061006200', 'hex'));
+assert.deepStrictEqual(
+  Buffer.allocUnsafeSlow(16).fill('a', 'utf16le'),
+  Buffer.from('61006100610061006100610061006100', 'hex'));
+
+assert.strictEqual(
+  Buffer.allocUnsafeSlow(16).fill('a', 'utf16le').toString('utf16le'),
+  'a'.repeat(8));
+assert.strictEqual(
+  Buffer.allocUnsafeSlow(16).fill('a', 'latin1').toString('latin1'),
+  'a'.repeat(16));
+assert.strictEqual(
+  Buffer.allocUnsafeSlow(16).fill('a', 'utf8').toString('utf8'),
+  'a'.repeat(16));
+
+assert.strictEqual(
+  Buffer.allocUnsafeSlow(16).fill('Љ', 'utf16le').toString('utf16le'),
+  'Љ'.repeat(8));
+assert.strictEqual(
+  Buffer.allocUnsafeSlow(16).fill('Љ', 'latin1').toString('latin1'),
+  '\t'.repeat(16));
+assert.strictEqual(
+  Buffer.allocUnsafeSlow(16).fill('Љ', 'utf8').toString('utf8'),
+  'Љ'.repeat(8));
+
+assert.throws(() => {
+  const buf = Buffer.from('a'.repeat(1000));
+
+  buf.fill('This is not correctly encoded', 'hex');
+}, {
+  code: 'ERR_INVALID_ARG_VALUE',
+  name: 'TypeError'
+});
+
+
+{
+  const bufEmptyString = Buffer.alloc(5, '');
+  assert.strictEqual(bufEmptyString.toString(), '\x00\x00\x00\x00\x00');
+
+  const bufEmptyArray = Buffer.alloc(5, []);
+  assert.strictEqual(bufEmptyArray.toString(), '\x00\x00\x00\x00\x00');
+
+  const bufEmptyBuffer = Buffer.alloc(5, Buffer.alloc(5));
+  assert.strictEqual(bufEmptyBuffer.toString(), '\x00\x00\x00\x00\x00');
+
+  const bufZero = Buffer.alloc(5, 0);
+  assert.strictEqual(bufZero.toString(), '\x00\x00\x00\x00\x00');
+}
diff --git a/test/js/node/test/parallel/test-buffer-from.js b/test/js/node/test/parallel/test-buffer-from.js
new file mode 100644
index 00000000000000..60236acfa0aea7
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-from.js
@@ -0,0 +1,141 @@
+'use strict';
+
+const common = require('../common');
+const { deepStrictEqual, strictEqual, throws } = require('assert');
+const { runInNewContext } = require('vm');
+
+const checkString = 'test';
+
+const check = Buffer.from(checkString);
+
+class MyString extends String {
+  constructor() {
+    super(checkString);
+  }
+}
+
+class MyPrimitive {
+  [Symbol.toPrimitive]() {
+    return checkString;
+  }
+}
+
+class MyBadPrimitive {
+  [Symbol.toPrimitive]() {
+    return 1;
+  }
+}
+
+deepStrictEqual(Buffer.from(new String(checkString)), check);
+deepStrictEqual(Buffer.from(new MyString()), check);
+deepStrictEqual(Buffer.from(new MyPrimitive()), check);
+deepStrictEqual(
+  Buffer.from(runInNewContext('new String(checkString)', { checkString })),
+  check
+);
+
+[
+  {},
+  new Boolean(true),
+  { valueOf() { return null; } },
+  { valueOf() { return undefined; } },
+  { valueOf: null },
+  { __proto__: null },
+  new Number(true),
+  new MyBadPrimitive(),
+  Symbol(),
+  5n,
+  (one, two, three) => {},
+  undefined,
+  null,
+].forEach((input) => {
+  const errObj = {
+    code: 'ERR_INVALID_ARG_TYPE',
+    name: 'TypeError',
+    message: 'The first argument must be of type string, ' +
+             'Buffer, ArrayBuffer, Array, or Array-like Object.' +
+             common.invalidArgTypeHelper(input)
+  };
+  throws(() => Buffer.from(input), errObj);
+  throws(() => Buffer.from(input, 'hex'), errObj);
+});
+
+Buffer.allocUnsafe(10); // Should not throw.
+Buffer.from('deadbeaf', 'hex'); // Should not throw.
+
+
+{
+  const u16 = new Uint16Array([0xffff]);
+  const b16 = Buffer.copyBytesFrom(u16);
+  u16[0] = 0;
+  strictEqual(b16.length, 2);
+  strictEqual(b16[0], 255);
+  strictEqual(b16[1], 255);
+}
+
+{
+  const u16 = new Uint16Array([0, 0xffff]);
+  const b16 = Buffer.copyBytesFrom(u16, 1, 5);
+  u16[0] = 0xffff;
+  u16[1] = 0;
+  strictEqual(b16.length, 2);
+  strictEqual(b16[0], 255);
+  strictEqual(b16[1], 255);
+}
+
+{
+  const u32 = new Uint32Array([0xffffffff]);
+  const b32 = Buffer.copyBytesFrom(u32);
+  u32[0] = 0;
+  strictEqual(b32.length, 4);
+  strictEqual(b32[0], 255);
+  strictEqual(b32[1], 255);
+  strictEqual(b32[2], 255);
+  strictEqual(b32[3], 255);
+}
+
+throws(() => {
+  Buffer.copyBytesFrom();
+}, {
+  code: 'ERR_INVALID_ARG_TYPE',
+});
+
+['', Symbol(), true, false, {}, [], () => {}, 1, 1n, null, undefined].forEach(
+  (notTypedArray) => throws(() => {
+    Buffer.copyBytesFrom('nope');
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE',
+  })
+);
+
+['', Symbol(), true, false, {}, [], () => {}, 1n].forEach((notANumber) =>
+  throws(() => {
+    Buffer.copyBytesFrom(new Uint8Array(1), notANumber);
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE',
+  })
+);
+
+[-1, NaN, 1.1, -Infinity].forEach((outOfRange) =>
+  throws(() => {
+    Buffer.copyBytesFrom(new Uint8Array(1), outOfRange);
+  }, {
+    code: 'ERR_OUT_OF_RANGE',
+  })
+);
+
+['', Symbol(), true, false, {}, [], () => {}, 1n].forEach((notANumber) =>
+  throws(() => {
+    Buffer.copyBytesFrom(new Uint8Array(1), 0, notANumber);
+  }, {
+    code: 'ERR_INVALID_ARG_TYPE',
+  })
+);
+
+[-1, NaN, 1.1, -Infinity].forEach((outOfRange) =>
+  throws(() => {
+    Buffer.copyBytesFrom(new Uint8Array(1), 0, outOfRange);
+  }, {
+    code: 'ERR_OUT_OF_RANGE',
+  })
+);
diff --git a/test/js/node/test/parallel/test-buffer-includes.js b/test/js/node/test/parallel/test-buffer-includes.js
new file mode 100644
index 00000000000000..5cc7648b1e0d92
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-includes.js
@@ -0,0 +1,304 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+const b = Buffer.from('abcdef');
+const buf_a = Buffer.from('a');
+const buf_bc = Buffer.from('bc');
+const buf_f = Buffer.from('f');
+const buf_z = Buffer.from('z');
+const buf_empty = Buffer.from('');
+
+assert(b.includes('a'));
+assert(!b.includes('a', 1));
+assert(!b.includes('a', -1));
+assert(!b.includes('a', -4));
+assert(b.includes('a', -b.length));
+assert(b.includes('a', NaN));
+assert(b.includes('a', -Infinity));
+assert(!b.includes('a', Infinity));
+assert(b.includes('bc'));
+assert(!b.includes('bc', 2));
+assert(!b.includes('bc', -1));
+assert(!b.includes('bc', -3));
+assert(b.includes('bc', -5));
+assert(b.includes('bc', NaN));
+assert(b.includes('bc', -Infinity));
+assert(!b.includes('bc', Infinity));
+assert(b.includes('f'), b.length - 1);
+assert(!b.includes('z'));
+assert(b.includes(''));
+assert(b.includes('', 1));
+assert(b.includes('', b.length + 1));
+assert(b.includes('', Infinity));
+assert(b.includes(buf_a));
+assert(!b.includes(buf_a, 1));
+assert(!b.includes(buf_a, -1));
+assert(!b.includes(buf_a, -4));
+assert(b.includes(buf_a, -b.length));
+assert(b.includes(buf_a, NaN));
+assert(b.includes(buf_a, -Infinity));
+assert(!b.includes(buf_a, Infinity));
+assert(b.includes(buf_bc));
+assert(!b.includes(buf_bc, 2));
+assert(!b.includes(buf_bc, -1));
+assert(!b.includes(buf_bc, -3));
+assert(b.includes(buf_bc, -5));
+assert(b.includes(buf_bc, NaN));
+assert(b.includes(buf_bc, -Infinity));
+assert(!b.includes(buf_bc, Infinity));
+assert(b.includes(buf_f), b.length - 1);
+assert(!b.includes(buf_z));
+assert(b.includes(buf_empty));
+assert(b.includes(buf_empty, 1));
+assert(b.includes(buf_empty, b.length + 1));
+assert(b.includes(buf_empty, Infinity));
+assert(b.includes(0x61));
+assert(!b.includes(0x61, 1));
+assert(!b.includes(0x61, -1));
+assert(!b.includes(0x61, -4));
+assert(b.includes(0x61, -b.length));
+assert(b.includes(0x61, NaN));
+assert(b.includes(0x61, -Infinity));
+assert(!b.includes(0x61, Infinity));
+assert(!b.includes(0x0));
+
+// test offsets
+assert(b.includes('d', 2));
+assert(b.includes('f', 5));
+assert(b.includes('f', -1));
+assert(!b.includes('f', 6));
+
+assert(b.includes(Buffer.from('d'), 2));
+assert(b.includes(Buffer.from('f'), 5));
+assert(b.includes(Buffer.from('f'), -1));
+assert(!b.includes(Buffer.from('f'), 6));
+
+assert(!Buffer.from('ff').includes(Buffer.from('f'), 1, 'ucs2'));
+
+// test hex encoding
+assert.strictEqual(
+  Buffer.from(b.toString('hex'), 'hex')
+    .includes('64', 0, 'hex'),
+  true
+);
+assert.strictEqual(
+  Buffer.from(b.toString('hex'), 'hex')
+    .includes(Buffer.from('64', 'hex'), 0, 'hex'),
+  true
+);
+
+// Test base64 encoding
+assert.strictEqual(
+  Buffer.from(b.toString('base64'), 'base64')
+    .includes('ZA==', 0, 'base64'),
+  true
+);
+assert.strictEqual(
+  Buffer.from(b.toString('base64'), 'base64')
+    .includes(Buffer.from('ZA==', 'base64'), 0, 'base64'),
+  true
+);
+
+// test ascii encoding
+assert.strictEqual(
+  Buffer.from(b.toString('ascii'), 'ascii')
+    .includes('d', 0, 'ascii'),
+  true
+);
+assert.strictEqual(
+  Buffer.from(b.toString('ascii'), 'ascii')
+    .includes(Buffer.from('d', 'ascii'), 0, 'ascii'),
+  true
+);
+
+// Test latin1 encoding
+assert.strictEqual(
+  Buffer.from(b.toString('latin1'), 'latin1')
+    .includes('d', 0, 'latin1'),
+  true
+);
+assert.strictEqual(
+  Buffer.from(b.toString('latin1'), 'latin1')
+    .includes(Buffer.from('d', 'latin1'), 0, 'latin1'),
+  true
+);
+
+// Test binary encoding
+assert.strictEqual(
+  Buffer.from(b.toString('binary'), 'binary')
+    .includes('d', 0, 'binary'),
+  true
+);
+assert.strictEqual(
+  Buffer.from(b.toString('binary'), 'binary')
+    .includes(Buffer.from('d', 'binary'), 0, 'binary'),
+  true
+);
+
+
+// test ucs2 encoding
+let twoByteString = Buffer.from('\u039a\u0391\u03a3\u03a3\u0395', 'ucs2');
+
+assert(twoByteString.includes('\u0395', 4, 'ucs2'));
+assert(twoByteString.includes('\u03a3', -4, 'ucs2'));
+assert(twoByteString.includes('\u03a3', -6, 'ucs2'));
+assert(twoByteString.includes(
+  Buffer.from('\u03a3', 'ucs2'), -6, 'ucs2'));
+assert(!twoByteString.includes('\u03a3', -2, 'ucs2'));
+
+const mixedByteStringUcs2 =
+  Buffer.from('\u039a\u0391abc\u03a3\u03a3\u0395', 'ucs2');
+assert(mixedByteStringUcs2.includes('bc', 0, 'ucs2'));
+assert(mixedByteStringUcs2.includes('\u03a3', 0, 'ucs2'));
+assert(!mixedByteStringUcs2.includes('\u0396', 0, 'ucs2'));
+
+assert.ok(
+  mixedByteStringUcs2.includes(Buffer.from('bc', 'ucs2'), 0, 'ucs2'));
+assert.ok(
+  mixedByteStringUcs2.includes(Buffer.from('\u03a3', 'ucs2'), 0, 'ucs2'));
+assert.ok(
+  !mixedByteStringUcs2.includes(Buffer.from('\u0396', 'ucs2'), 0, 'ucs2'));
+
+twoByteString = Buffer.from('\u039a\u0391\u03a3\u03a3\u0395', 'ucs2');
+
+// Test single char pattern
+assert(twoByteString.includes('\u039a', 0, 'ucs2'));
+assert(twoByteString.includes('\u0391', 0, 'ucs2'), 'Alpha');
+assert(twoByteString.includes('\u03a3', 0, 'ucs2'), 'First Sigma');
+assert(twoByteString.includes('\u03a3', 6, 'ucs2'), 'Second Sigma');
+assert(twoByteString.includes('\u0395', 0, 'ucs2'), 'Epsilon');
+assert(!twoByteString.includes('\u0392', 0, 'ucs2'), 'Not beta');
+
+// Test multi-char pattern
+assert(twoByteString.includes('\u039a\u0391', 0, 'ucs2'), 'Lambda Alpha');
+assert(twoByteString.includes('\u0391\u03a3', 0, 'ucs2'), 'Alpha Sigma');
+assert(twoByteString.includes('\u03a3\u03a3', 0, 'ucs2'), 'Sigma Sigma');
+assert(twoByteString.includes('\u03a3\u0395', 0, 'ucs2'), 'Sigma Epsilon');
+
+const mixedByteStringUtf8 = Buffer.from('\u039a\u0391abc\u03a3\u03a3\u0395');
+assert(mixedByteStringUtf8.includes('bc'));
+assert(mixedByteStringUtf8.includes('bc', 5));
+assert(mixedByteStringUtf8.includes('bc', -8));
+assert(mixedByteStringUtf8.includes('\u03a3'));
+assert(!mixedByteStringUtf8.includes('\u0396'));
+
+
+// Test complex string includes algorithms. Only trigger for long strings.
+// Long string that isn't a simple repeat of a shorter string.
+let longString = 'A';
+for (let i = 66; i < 76; i++) {  // from 'B' to 'K'
+  longString = longString + String.fromCharCode(i) + longString;
+}
+
+const longBufferString = Buffer.from(longString);
+
+// Pattern of 15 chars, repeated every 16 chars in long
+let pattern = 'ABACABADABACABA';
+for (let i = 0; i < longBufferString.length - pattern.length; i += 7) {
+  const includes = longBufferString.includes(pattern, i);
+  assert(includes, `Long ABACABA...-string at index ${i}`);
+}
+assert(longBufferString.includes('AJABACA'), 'Long AJABACA, First J');
+assert(longBufferString.includes('AJABACA', 511), 'Long AJABACA, Second J');
+
+pattern = 'JABACABADABACABA';
+assert(longBufferString.includes(pattern), 'Long JABACABA..., First J');
+assert(longBufferString.includes(pattern, 512), 'Long JABACABA..., Second J');
+
+// Search for a non-ASCII string in a pure ASCII string.
+const asciiString = Buffer.from(
+  'arglebargleglopglyfarglebargleglopglyfarglebargleglopglyf');
+assert(!asciiString.includes('\x2061'));
+assert(asciiString.includes('leb', 0));
+
+// Search in string containing many non-ASCII chars.
+const allCodePoints = [];
+for (let i = 0; i < 65534; i++) allCodePoints[i] = i;
+const allCharsString = String.fromCharCode.apply(String, allCodePoints) +
+    String.fromCharCode(65534, 65535);
+const allCharsBufferUtf8 = Buffer.from(allCharsString);
+const allCharsBufferUcs2 = Buffer.from(allCharsString, 'ucs2');
+
+// Search for string long enough to trigger complex search with ASCII pattern
+// and UC16 subject.
+assert(!allCharsBufferUtf8.includes('notfound'));
+assert(!allCharsBufferUcs2.includes('notfound'));
+
+// Find substrings in Utf8.
+let lengths = [1, 3, 15];  // Single char, simple and complex.
+let indices = [0x5, 0x60, 0x400, 0x680, 0x7ee, 0xFF02, 0x16610, 0x2f77b];
+for (let lengthIndex = 0; lengthIndex < lengths.length; lengthIndex++) {
+  for (let i = 0; i < indices.length; i++) {
+    const index = indices[i];
+    let length = lengths[lengthIndex];
+
+    if (index + length > 0x7F) {
+      length = 2 * length;
+    }
+
+    if (index + length > 0x7FF) {
+      length = 3 * length;
+    }
+
+    if (index + length > 0xFFFF) {
+      length = 4 * length;
+    }
+
+    const patternBufferUtf8 = allCharsBufferUtf8.slice(index, index + length);
+    assert(index, allCharsBufferUtf8.includes(patternBufferUtf8));
+
+    const patternStringUtf8 = patternBufferUtf8.toString();
+    assert(index, allCharsBufferUtf8.includes(patternStringUtf8));
+  }
+}
+
+// Find substrings in Usc2.
+lengths = [2, 4, 16];  // Single char, simple and complex.
+indices = [0x5, 0x65, 0x105, 0x205, 0x285, 0x2005, 0x2085, 0xfff0];
+for (let lengthIndex = 0; lengthIndex < lengths.length; lengthIndex++) {
+  for (let i = 0; i < indices.length; i++) {
+    const index = indices[i] * 2;
+    const length = lengths[lengthIndex];
+
+    const patternBufferUcs2 =
+      allCharsBufferUcs2.slice(index, index + length);
+    assert.ok(
+      allCharsBufferUcs2.includes(patternBufferUcs2, 0, 'ucs2'));
+
+    const patternStringUcs2 = patternBufferUcs2.toString('ucs2');
+    assert.ok(
+      allCharsBufferUcs2.includes(patternStringUcs2, 0, 'ucs2'));
+  }
+}
+
+[
+  () => { },
+  {},
+  [],
+].forEach((val) => {
+  assert.throws(
+    () => b.includes(val),
+    {
+      code: 'ERR_INVALID_ARG_TYPE',
+      name: 'TypeError',
+      message: 'The "value" argument must be of type number, string, Buffer, or Uint8Array.' + common.invalidArgTypeHelper(val)
+    }
+  );
+});
+
+// Test truncation of Number arguments to uint8
+{
+  const buf = Buffer.from('this is a test');
+  assert.ok(buf.includes(0x6973));
+  assert.ok(buf.includes(0x697320));
+  assert.ok(buf.includes(0x69732069));
+  assert.ok(buf.includes(0x697374657374));
+  assert.ok(buf.includes(0x69737374));
+  assert.ok(buf.includes(0x69737465));
+  assert.ok(buf.includes(0x69737465));
+  assert.ok(buf.includes(-140));
+  assert.ok(buf.includes(-152));
+  assert.ok(!buf.includes(0xff));
+  assert.ok(!buf.includes(0xffff));
+}
diff --git a/test/js/node/test/parallel/test-buffer-indexof.js b/test/js/node/test/parallel/test-buffer-indexof.js
new file mode 100644
index 00000000000000..524230c01bc7de
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-indexof.js
@@ -0,0 +1,629 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+
+const b = Buffer.from('abcdef');
+const buf_a = Buffer.from('a');
+const buf_bc = Buffer.from('bc');
+const buf_f = Buffer.from('f');
+const buf_z = Buffer.from('z');
+const buf_empty = Buffer.from('');
+
+const s = 'abcdef';
+
+assert.strictEqual(b.indexOf('a'), 0);
+assert.strictEqual(b.indexOf('a', 1), -1);
+assert.strictEqual(b.indexOf('a', -1), -1);
+assert.strictEqual(b.indexOf('a', -4), -1);
+assert.strictEqual(b.indexOf('a', -b.length), 0);
+assert.strictEqual(b.indexOf('a', NaN), 0);
+assert.strictEqual(b.indexOf('a', -Infinity), 0);
+assert.strictEqual(b.indexOf('a', Infinity), -1);
+assert.strictEqual(b.indexOf('bc'), 1);
+assert.strictEqual(b.indexOf('bc', 2), -1);
+assert.strictEqual(b.indexOf('bc', -1), -1);
+assert.strictEqual(b.indexOf('bc', -3), -1);
+assert.strictEqual(b.indexOf('bc', -5), 1);
+assert.strictEqual(b.indexOf('bc', NaN), 1);
+assert.strictEqual(b.indexOf('bc', -Infinity), 1);
+assert.strictEqual(b.indexOf('bc', Infinity), -1);
+assert.strictEqual(b.indexOf('f'), b.length - 1);
+assert.strictEqual(b.indexOf('z'), -1);
+assert.strictEqual(b.indexOf(''), 0);
+assert.strictEqual(b.indexOf('', 1), 1);
+assert.strictEqual(b.indexOf('', b.length + 1), b.length);
+assert.strictEqual(b.indexOf('', Infinity), b.length);
+assert.strictEqual(b.indexOf(buf_a), 0);
+assert.strictEqual(b.indexOf(buf_a, 1), -1);
+assert.strictEqual(b.indexOf(buf_a, -1), -1);
+assert.strictEqual(b.indexOf(buf_a, -4), -1);
+assert.strictEqual(b.indexOf(buf_a, -b.length), 0);
+assert.strictEqual(b.indexOf(buf_a, NaN), 0);
+assert.strictEqual(b.indexOf(buf_a, -Infinity), 0);
+assert.strictEqual(b.indexOf(buf_a, Infinity), -1);
+assert.strictEqual(b.indexOf(buf_bc), 1);
+assert.strictEqual(b.indexOf(buf_bc, 2), -1);
+assert.strictEqual(b.indexOf(buf_bc, -1), -1);
+assert.strictEqual(b.indexOf(buf_bc, -3), -1);
+assert.strictEqual(b.indexOf(buf_bc, -5), 1);
+assert.strictEqual(b.indexOf(buf_bc, NaN), 1);
+assert.strictEqual(b.indexOf(buf_bc, -Infinity), 1);
+assert.strictEqual(b.indexOf(buf_bc, Infinity), -1);
+assert.strictEqual(b.indexOf(buf_f), b.length - 1);
+assert.strictEqual(b.indexOf(buf_z), -1);
+assert.strictEqual(b.indexOf(buf_empty), 0);
+assert.strictEqual(b.indexOf(buf_empty, 1), 1);
+assert.strictEqual(b.indexOf(buf_empty, b.length + 1), b.length);
+assert.strictEqual(b.indexOf(buf_empty, Infinity), b.length);
+assert.strictEqual(b.indexOf(0x61), 0);
+assert.strictEqual(b.indexOf(0x61, 1), -1);
+assert.strictEqual(b.indexOf(0x61, -1), -1);
+assert.strictEqual(b.indexOf(0x61, -4), -1);
+assert.strictEqual(b.indexOf(0x61, -b.length), 0);
+assert.strictEqual(b.indexOf(0x61, NaN), 0);
+assert.strictEqual(b.indexOf(0x61, -Infinity), 0);
+assert.strictEqual(b.indexOf(0x61, Infinity), -1);
+assert.strictEqual(b.indexOf(0x0), -1);
+
+// test offsets
+assert.strictEqual(b.indexOf('d', 2), 3);
+assert.strictEqual(b.indexOf('f', 5), 5);
+assert.strictEqual(b.indexOf('f', -1), 5);
+assert.strictEqual(b.indexOf('f', 6), -1);
+
+assert.strictEqual(b.indexOf(Buffer.from('d'), 2), 3);
+assert.strictEqual(b.indexOf(Buffer.from('f'), 5), 5);
+assert.strictEqual(b.indexOf(Buffer.from('f'), -1), 5);
+assert.strictEqual(b.indexOf(Buffer.from('f'), 6), -1);
+
+assert.strictEqual(Buffer.from('ff').indexOf(Buffer.from('f'), 1, 'ucs2'), -1);
+
+// Test invalid and uppercase encoding
+assert.strictEqual(b.indexOf('b', 'utf8'), 1);
+assert.strictEqual(b.indexOf('b', 'UTF8'), 1);
+assert.strictEqual(b.indexOf('62', 'HEX'), 1);
+assert.throws(() => b.indexOf('bad', 'enc'), /Unknown encoding: enc/);
+
+// test hex encoding
+assert.strictEqual(
+  Buffer.from(b.toString('hex'), 'hex')
+    .indexOf('64', 0, 'hex'),
+  3
+);
+assert.strictEqual(
+  Buffer.from(b.toString('hex'), 'hex')
+    .indexOf(Buffer.from('64', 'hex'), 0, 'hex'),
+  3
+);
+
+// Test base64 encoding
+assert.strictEqual(
+  Buffer.from(b.toString('base64'), 'base64')
+    .indexOf('ZA==', 0, 'base64'),
+  3
+);
+assert.strictEqual(
+  Buffer.from(b.toString('base64'), 'base64')
+    .indexOf(Buffer.from('ZA==', 'base64'), 0, 'base64'),
+  3
+);
+
+// Test base64url encoding
+assert.strictEqual(
+  Buffer.from(b.toString('base64url'), 'base64url')
+    .indexOf('ZA==', 0, 'base64url'),
+  3
+);
+
+// test ascii encoding
+assert.strictEqual(
+  Buffer.from(b.toString('ascii'), 'ascii')
+    .indexOf('d', 0, 'ascii'),
+  3
+);
+assert.strictEqual(
+  Buffer.from(b.toString('ascii'), 'ascii')
+    .indexOf(Buffer.from('d', 'ascii'), 0, 'ascii'),
+  3
+);
+
+// Test latin1 encoding
+assert.strictEqual(
+  Buffer.from(b.toString('latin1'), 'latin1')
+    .indexOf('d', 0, 'latin1'),
+  3
+);
+assert.strictEqual(
+  Buffer.from(b.toString('latin1'), 'latin1')
+    .indexOf(Buffer.from('d', 'latin1'), 0, 'latin1'),
+  3
+);
+assert.strictEqual(
+  Buffer.from('aa\u00e8aa', 'latin1')
+    .indexOf('\u00e8', 'latin1'),
+  2
+);
+assert.strictEqual(
+  Buffer.from('\u00e8', 'latin1')
+    .indexOf('\u00e8', 'latin1'),
+  0
+);
+assert.strictEqual(
+  Buffer.from('\u00e8', 'latin1')
+    .indexOf(Buffer.from('\u00e8', 'latin1'), 'latin1'),
+  0
+);
+
+// Test binary encoding
+assert.strictEqual(
+  Buffer.from(b.toString('binary'), 'binary')
+    .indexOf('d', 0, 'binary'),
+  3
+);
+assert.strictEqual(
+  Buffer.from(b.toString('binary'), 'binary')
+    .indexOf(Buffer.from('d', 'binary'), 0, 'binary'),
+  3
+);
+assert.strictEqual(
+  Buffer.from('aa\u00e8aa', 'binary')
+    .indexOf('\u00e8', 'binary'),
+  2
+);
+assert.strictEqual(
+  Buffer.from('\u00e8', 'binary')
+    .indexOf('\u00e8', 'binary'),
+  0
+);
+assert.strictEqual(
+  Buffer.from('\u00e8', 'binary')
+    .indexOf(Buffer.from('\u00e8', 'binary'), 'binary'),
+  0
+);
+
+
+// Test optional offset with passed encoding
+assert.strictEqual(Buffer.from('aaaa0').indexOf('30', 'hex'), 4);
+assert.strictEqual(Buffer.from('aaaa00a').indexOf('3030', 'hex'), 4);
+
+{
+  // Test usc2 and utf16le encoding
+  ['ucs2', 'utf16le'].forEach((encoding) => {
+    const twoByteString = Buffer.from(
+      '\u039a\u0391\u03a3\u03a3\u0395', encoding);
+
+    assert.strictEqual(twoByteString.indexOf('\u0395', 4, encoding), 8);
+    assert.strictEqual(twoByteString.indexOf('\u03a3', -4, encoding), 6);
+    assert.strictEqual(twoByteString.indexOf('\u03a3', -6, encoding), 4);
+    assert.strictEqual(twoByteString.indexOf(
+      Buffer.from('\u03a3', encoding), -6, encoding), 4);
+    assert.strictEqual(-1, twoByteString.indexOf('\u03a3', -2, encoding));
+  });
+}
+
+const mixedByteStringUcs2 =
+    Buffer.from('\u039a\u0391abc\u03a3\u03a3\u0395', 'ucs2');
+assert.strictEqual(mixedByteStringUcs2.indexOf('bc', 0, 'ucs2'), 6);
+assert.strictEqual(mixedByteStringUcs2.indexOf('\u03a3', 0, 'ucs2'), 10);
+assert.strictEqual(-1, mixedByteStringUcs2.indexOf('\u0396', 0, 'ucs2'));
+
+assert.strictEqual(
+  mixedByteStringUcs2.indexOf(Buffer.from('bc', 'ucs2'), 0, 'ucs2'), 6);
+assert.strictEqual(
+  mixedByteStringUcs2.indexOf(Buffer.from('\u03a3', 'ucs2'), 0, 'ucs2'), 10);
+assert.strictEqual(
+  -1, mixedByteStringUcs2.indexOf(Buffer.from('\u0396', 'ucs2'), 0, 'ucs2'));
+
+{
+  const twoByteString = Buffer.from('\u039a\u0391\u03a3\u03a3\u0395', 'ucs2');
+
+  // Test single char pattern
+  assert.strictEqual(twoByteString.indexOf('\u039a', 0, 'ucs2'), 0);
+  let index = twoByteString.indexOf('\u0391', 0, 'ucs2');
+  assert.strictEqual(index, 2, `Alpha - at index ${index}`);
+  index = twoByteString.indexOf('\u03a3', 0, 'ucs2');
+  assert.strictEqual(index, 4, `First Sigma - at index ${index}`);
+  index = twoByteString.indexOf('\u03a3', 6, 'ucs2');
+  assert.strictEqual(index, 6, `Second Sigma - at index ${index}`);
+  index = twoByteString.indexOf('\u0395', 0, 'ucs2');
+  assert.strictEqual(index, 8, `Epsilon - at index ${index}`);
+  index = twoByteString.indexOf('\u0392', 0, 'ucs2');
+  assert.strictEqual(-1, index, `Not beta - at index ${index}`);
+
+  // Test multi-char pattern
+  index = twoByteString.indexOf('\u039a\u0391', 0, 'ucs2');
+  assert.strictEqual(index, 0, `Lambda Alpha - at index ${index}`);
+  index = twoByteString.indexOf('\u0391\u03a3', 0, 'ucs2');
+  assert.strictEqual(index, 2, `Alpha Sigma - at index ${index}`);
+  index = twoByteString.indexOf('\u03a3\u03a3', 0, 'ucs2');
+  assert.strictEqual(index, 4, `Sigma Sigma - at index ${index}`);
+  index = twoByteString.indexOf('\u03a3\u0395', 0, 'ucs2');
+  assert.strictEqual(index, 6, `Sigma Epsilon - at index ${index}`);
+}
+
+const mixedByteStringUtf8 = Buffer.from('\u039a\u0391abc\u03a3\u03a3\u0395');
+assert.strictEqual(mixedByteStringUtf8.indexOf('bc'), 5);
+assert.strictEqual(mixedByteStringUtf8.indexOf('bc', 5), 5);
+assert.strictEqual(mixedByteStringUtf8.indexOf('bc', -8), 5);
+assert.strictEqual(mixedByteStringUtf8.indexOf('\u03a3'), 7);
+assert.strictEqual(mixedByteStringUtf8.indexOf('\u0396'), -1);
+
+
+// Test complex string indexOf algorithms. Only trigger for long strings.
+// Long string that isn't a simple repeat of a shorter string.
+let longString = 'A';
+for (let i = 66; i < 76; i++) {  // from 'B' to 'K'
+  longString = longString + String.fromCharCode(i) + longString;
+}
+
+const longBufferString = Buffer.from(longString);
+
+// Pattern of 15 chars, repeated every 16 chars in long
+let pattern = 'ABACABADABACABA';
+for (let i = 0; i < longBufferString.length - pattern.length; i += 7) {
+  const index = longBufferString.indexOf(pattern, i);
+  assert.strictEqual((i + 15) & ~0xf, index,
+                     `Long ABACABA...-string at index ${i}`);
+}
+
+let index = longBufferString.indexOf('AJABACA');
+assert.strictEqual(index, 510, `Long AJABACA, First J - at index ${index}`);
+index = longBufferString.indexOf('AJABACA', 511);
+assert.strictEqual(index, 1534, `Long AJABACA, Second J - at index ${index}`);
+
+pattern = 'JABACABADABACABA';
+index = longBufferString.indexOf(pattern);
+assert.strictEqual(index, 511, `Long JABACABA..., First J - at index ${index}`);
+index = longBufferString.indexOf(pattern, 512);
+assert.strictEqual(
+  index, 1535, `Long JABACABA..., Second J - at index ${index}`);
+
+// Search for a non-ASCII string in a pure ASCII string.
+const asciiString = Buffer.from(
+  'arglebargleglopglyfarglebargleglopglyfarglebargleglopglyf');
+assert.strictEqual(-1, asciiString.indexOf('\x2061'));
+assert.strictEqual(asciiString.indexOf('leb', 0), 3);
+
+// Search in string containing many non-ASCII chars.
+const allCodePoints = [];
+for (let i = 0; i < 65534; i++) allCodePoints[i] = i;
+const allCharsString = String.fromCharCode.apply(String, allCodePoints) + String.fromCharCode(65534, 65535);
+const allCharsBufferUtf8 = Buffer.from(allCharsString);
+const allCharsBufferUcs2 = Buffer.from(allCharsString, 'ucs2');
+
+// Search for string long enough to trigger complex search with ASCII pattern
+// and UC16 subject.
+assert.strictEqual(-1, allCharsBufferUtf8.indexOf('notfound'));
+assert.strictEqual(-1, allCharsBufferUcs2.indexOf('notfound'));
+
+// Needle is longer than haystack, but only because it's encoded as UTF-16
+assert.strictEqual(Buffer.from('aaaa').indexOf('a'.repeat(4), 'ucs2'), -1);
+
+assert.strictEqual(Buffer.from('aaaa').indexOf('a'.repeat(4), 'utf8'), 0);
+assert.strictEqual(Buffer.from('aaaa').indexOf('你好', 'ucs2'), -1);
+
+// Haystack has odd length, but the needle is UCS2.
+assert.strictEqual(Buffer.from('aaaaa').indexOf('b', 'ucs2'), -1);
+
+{
+  // Find substrings in Utf8.
+  const lengths = [1, 3, 15];  // Single char, simple and complex.
+  const indices = [0x5, 0x60, 0x400, 0x680, 0x7ee, 0xFF02, 0x16610, 0x2f77b];
+  for (let lengthIndex = 0; lengthIndex < lengths.length; lengthIndex++) {
+    for (let i = 0; i < indices.length; i++) {
+      const index = indices[i];
+      let length = lengths[lengthIndex];
+
+      if (index + length > 0x7F) {
+        length = 2 * length;
+      }
+
+      if (index + length > 0x7FF) {
+        length = 3 * length;
+      }
+
+      if (index + length > 0xFFFF) {
+        length = 4 * length;
+      }
+
+      const patternBufferUtf8 = allCharsBufferUtf8.slice(index, index + length);
+      assert.strictEqual(index, allCharsBufferUtf8.indexOf(patternBufferUtf8));
+
+      const patternStringUtf8 = patternBufferUtf8.toString();
+      assert.strictEqual(index, allCharsBufferUtf8.indexOf(patternStringUtf8));
+    }
+  }
+}
+
+{
+  // Find substrings in Usc2.
+  const lengths = [2, 4, 16];  // Single char, simple and complex.
+  const indices = [0x5, 0x65, 0x105, 0x205, 0x285, 0x2005, 0x2085, 0xfff0];
+  for (let lengthIndex = 0; lengthIndex < lengths.length; lengthIndex++) {
+    for (let i = 0; i < indices.length; i++) {
+      const index = indices[i] * 2;
+      const length = lengths[lengthIndex];
+
+      const patternBufferUcs2 = allCharsBufferUcs2.slice(index, index + length);
+      const actualB = allCharsBufferUcs2.indexOf(patternBufferUcs2, 0, 'ucs2');
+      assert.strictEqual(actualB, index);
+
+      const patternStringUcs2 = patternBufferUcs2.toString('ucs2');
+      const actualS = allCharsBufferUcs2.indexOf(patternStringUcs2, 0, 'ucs2');
+      assert.strictEqual(actualS, index);
+    }
+  }
+}
+
+[
+  () => {},
+  {},
+  [],
+].forEach((val) => {
+  assert.throws(
+    () => b.indexOf(val),
+    {
+      code: 'ERR_INVALID_ARG_TYPE',
+      name: 'TypeError',
+      message: 'The "value" argument must be of type number, string, Buffer, or Uint8Array.' + common.invalidArgTypeHelper(val)
+    }
+  );
+});
+
+// Test weird offset arguments.
+// The following offsets coerce to NaN or 0, searching the whole Buffer
+assert.strictEqual(b.indexOf('b', undefined), 1);
+assert.strictEqual(b.indexOf('b', {}), 1);
+assert.strictEqual(b.indexOf('b', 0), 1);
+assert.strictEqual(b.indexOf('b', null), 1);
+assert.strictEqual(b.indexOf('b', []), 1);
+
+// The following offset coerces to 2, in other words +[2] === 2
+assert.strictEqual(b.indexOf('b', [2]), -1);
+
+// Behavior should match String.indexOf()
+assert.strictEqual(
+  b.indexOf('b', undefined),
+  s.indexOf('b', undefined));
+assert.strictEqual(
+  b.indexOf('b', {}),
+  s.indexOf('b', {}));
+assert.strictEqual(
+  b.indexOf('b', 0),
+  s.indexOf('b', 0));
+assert.strictEqual(
+  b.indexOf('b', null),
+  s.indexOf('b', null));
+assert.strictEqual(
+  b.indexOf('b', []),
+  s.indexOf('b', []));
+assert.strictEqual(
+  b.indexOf('b', [2]),
+  s.indexOf('b', [2]));
+
+// All code for handling encodings is shared between Buffer.indexOf and
+// Buffer.lastIndexOf, so only testing the separate lastIndexOf semantics.
+
+// Test lastIndexOf basic functionality; Buffer b contains 'abcdef'.
+// lastIndexOf string:
+assert.strictEqual(b.lastIndexOf('a'), 0);
+assert.strictEqual(b.lastIndexOf('a', 1), 0);
+assert.strictEqual(b.lastIndexOf('b', 1), 1);
+assert.strictEqual(b.lastIndexOf('c', 1), -1);
+assert.strictEqual(b.lastIndexOf('a', -1), 0);
+assert.strictEqual(b.lastIndexOf('a', -4), 0);
+assert.strictEqual(b.lastIndexOf('a', -b.length), 0);
+assert.strictEqual(b.lastIndexOf('a', -b.length - 1), -1);
+assert.strictEqual(b.lastIndexOf('a', NaN), 0);
+assert.strictEqual(b.lastIndexOf('a', -Infinity), -1);
+assert.strictEqual(b.lastIndexOf('a', Infinity), 0);
+// lastIndexOf Buffer:
+assert.strictEqual(b.lastIndexOf(buf_a), 0);
+assert.strictEqual(b.lastIndexOf(buf_a, 1), 0);
+assert.strictEqual(b.lastIndexOf(buf_a, -1), 0);
+assert.strictEqual(b.lastIndexOf(buf_a, -4), 0);
+assert.strictEqual(b.lastIndexOf(buf_a, -b.length), 0);
+assert.strictEqual(b.lastIndexOf(buf_a, -b.length - 1), -1);
+assert.strictEqual(b.lastIndexOf(buf_a, NaN), 0);
+assert.strictEqual(b.lastIndexOf(buf_a, -Infinity), -1);
+assert.strictEqual(b.lastIndexOf(buf_a, Infinity), 0);
+assert.strictEqual(b.lastIndexOf(buf_bc), 1);
+assert.strictEqual(b.lastIndexOf(buf_bc, 2), 1);
+assert.strictEqual(b.lastIndexOf(buf_bc, -1), 1);
+assert.strictEqual(b.lastIndexOf(buf_bc, -3), 1);
+assert.strictEqual(b.lastIndexOf(buf_bc, -5), 1);
+assert.strictEqual(b.lastIndexOf(buf_bc, -6), -1);
+assert.strictEqual(b.lastIndexOf(buf_bc, NaN), 1);
+assert.strictEqual(b.lastIndexOf(buf_bc, -Infinity), -1);
+assert.strictEqual(b.lastIndexOf(buf_bc, Infinity), 1);
+assert.strictEqual(b.lastIndexOf(buf_f), b.length - 1);
+assert.strictEqual(b.lastIndexOf(buf_z), -1);
+assert.strictEqual(b.lastIndexOf(buf_empty), b.length);
+assert.strictEqual(b.lastIndexOf(buf_empty, 1), 1);
+assert.strictEqual(b.lastIndexOf(buf_empty, b.length + 1), b.length);
+assert.strictEqual(b.lastIndexOf(buf_empty, Infinity), b.length);
+// lastIndexOf number:
+assert.strictEqual(b.lastIndexOf(0x61), 0);
+assert.strictEqual(b.lastIndexOf(0x61, 1), 0);
+assert.strictEqual(b.lastIndexOf(0x61, -1), 0);
+assert.strictEqual(b.lastIndexOf(0x61, -4), 0);
+assert.strictEqual(b.lastIndexOf(0x61, -b.length), 0);
+assert.strictEqual(b.lastIndexOf(0x61, -b.length - 1), -1);
+assert.strictEqual(b.lastIndexOf(0x61, NaN), 0);
+assert.strictEqual(b.lastIndexOf(0x61, -Infinity), -1);
+assert.strictEqual(b.lastIndexOf(0x61, Infinity), 0);
+assert.strictEqual(b.lastIndexOf(0x0), -1);
+
+// Test weird offset arguments.
+// The following offsets coerce to NaN, searching the whole Buffer
+assert.strictEqual(b.lastIndexOf('b', undefined), 1);
+assert.strictEqual(b.lastIndexOf('b', {}), 1);
+
+// The following offsets coerce to 0
+assert.strictEqual(b.lastIndexOf('b', 0), -1);
+assert.strictEqual(b.lastIndexOf('b', null), -1);
+assert.strictEqual(b.lastIndexOf('b', []), -1);
+
+// The following offset coerces to 2, in other words +[2] === 2
+assert.strictEqual(b.lastIndexOf('b', [2]), 1);
+
+// Behavior should match String.lastIndexOf()
+assert.strictEqual(
+  b.lastIndexOf('b', undefined),
+  s.lastIndexOf('b', undefined));
+assert.strictEqual(
+  b.lastIndexOf('b', {}),
+  s.lastIndexOf('b', {}));
+assert.strictEqual(
+  b.lastIndexOf('b', 0),
+  s.lastIndexOf('b', 0));
+assert.strictEqual(
+  b.lastIndexOf('b', null),
+  s.lastIndexOf('b', null));
+assert.strictEqual(
+  b.lastIndexOf('b', []),
+  s.lastIndexOf('b', []));
+assert.strictEqual(
+  b.lastIndexOf('b', [2]),
+  s.lastIndexOf('b', [2]));
+
+// Test needles longer than the haystack.
+assert.strictEqual(b.lastIndexOf('aaaaaaaaaaaaaaa', 'ucs2'), -1);
+assert.strictEqual(b.lastIndexOf('aaaaaaaaaaaaaaa', 'utf8'), -1);
+assert.strictEqual(b.lastIndexOf('aaaaaaaaaaaaaaa', 'latin1'), -1);
+assert.strictEqual(b.lastIndexOf('aaaaaaaaaaaaaaa', 'binary'), -1);
+assert.strictEqual(b.lastIndexOf(Buffer.from('aaaaaaaaaaaaaaa')), -1);
+assert.strictEqual(b.lastIndexOf('aaaaaaaaaaaaaaa', 2, 'ucs2'), -1);
+assert.strictEqual(b.lastIndexOf('aaaaaaaaaaaaaaa', 3, 'utf8'), -1);
+assert.strictEqual(b.lastIndexOf('aaaaaaaaaaaaaaa', 5, 'latin1'), -1);
+assert.strictEqual(b.lastIndexOf('aaaaaaaaaaaaaaa', 5, 'binary'), -1);
+assert.strictEqual(b.lastIndexOf(Buffer.from('aaaaaaaaaaaaaaa'), 7), -1);
+
+// 你好 expands to a total of 6 bytes using UTF-8 and 4 bytes using UTF-16
+assert.strictEqual(buf_bc.lastIndexOf('你好', 'ucs2'), -1);
+assert.strictEqual(buf_bc.lastIndexOf('你好', 'utf8'), -1);
+assert.strictEqual(buf_bc.lastIndexOf('你好', 'latin1'), -1);
+assert.strictEqual(buf_bc.lastIndexOf('你好', 'binary'), -1);
+assert.strictEqual(buf_bc.lastIndexOf(Buffer.from('你好')), -1);
+assert.strictEqual(buf_bc.lastIndexOf('你好', 2, 'ucs2'), -1);
+assert.strictEqual(buf_bc.lastIndexOf('你好', 3, 'utf8'), -1);
+assert.strictEqual(buf_bc.lastIndexOf('你好', 5, 'latin1'), -1);
+assert.strictEqual(buf_bc.lastIndexOf('你好', 5, 'binary'), -1);
+assert.strictEqual(buf_bc.lastIndexOf(Buffer.from('你好'), 7), -1);
+
+// Test lastIndexOf on a longer buffer:
+const bufferString = Buffer.from('a man a plan a canal panama');
+assert.strictEqual(bufferString.lastIndexOf('canal'), 15);
+assert.strictEqual(bufferString.lastIndexOf('panama'), 21);
+assert.strictEqual(bufferString.lastIndexOf('a man a plan a canal panama'), 0);
+assert.strictEqual(-1, bufferString.lastIndexOf('a man a plan a canal mexico'));
+assert.strictEqual(-1, bufferString
+  .lastIndexOf('a man a plan a canal mexico city'));
+assert.strictEqual(-1, bufferString.lastIndexOf(Buffer.from('a'.repeat(1000))));
+assert.strictEqual(bufferString.lastIndexOf('a man a plan', 4), 0);
+assert.strictEqual(bufferString.lastIndexOf('a '), 13);
+assert.strictEqual(bufferString.lastIndexOf('a ', 13), 13);
+assert.strictEqual(bufferString.lastIndexOf('a ', 12), 6);
+assert.strictEqual(bufferString.lastIndexOf('a ', 5), 0);
+assert.strictEqual(bufferString.lastIndexOf('a ', -1), 13);
+assert.strictEqual(bufferString.lastIndexOf('a ', -27), 0);
+assert.strictEqual(-1, bufferString.lastIndexOf('a ', -28));
+
+// Test lastIndexOf for the case that the first character can be found,
+// but in a part of the buffer that does not make search to search
+// due do length constraints.
+const abInUCS2 = Buffer.from('ab', 'ucs2');
+assert.strictEqual(-1, Buffer.from('µaaaa¶bbbb', 'latin1').lastIndexOf('µ'));
+assert.strictEqual(-1, Buffer.from('µaaaa¶bbbb', 'binary').lastIndexOf('µ'));
+assert.strictEqual(-1, Buffer.from('bc').lastIndexOf('ab'));
+assert.strictEqual(-1, Buffer.from('abc').lastIndexOf('qa'));
+assert.strictEqual(-1, Buffer.from('abcdef').lastIndexOf('qabc'));
+assert.strictEqual(-1, Buffer.from('bc').lastIndexOf(Buffer.from('ab')));
+assert.strictEqual(-1, Buffer.from('bc', 'ucs2').lastIndexOf('ab', 'ucs2'));
+assert.strictEqual(-1, Buffer.from('bc', 'ucs2').lastIndexOf(abInUCS2));
+
+assert.strictEqual(Buffer.from('abc').lastIndexOf('ab'), 0);
+assert.strictEqual(Buffer.from('abc').lastIndexOf('ab', 1), 0);
+assert.strictEqual(Buffer.from('abc').lastIndexOf('ab', 2), 0);
+assert.strictEqual(Buffer.from('abc').lastIndexOf('ab', 3), 0);
+
+// The above tests test the LINEAR and SINGLE-CHAR strategies.
+// Now, we test the BOYER-MOORE-HORSPOOL strategy.
+// Test lastIndexOf on a long buffer w multiple matches:
+pattern = 'JABACABADABACABA';
+assert.strictEqual(longBufferString.lastIndexOf(pattern), 1535);
+assert.strictEqual(longBufferString.lastIndexOf(pattern, 1535), 1535);
+assert.strictEqual(longBufferString.lastIndexOf(pattern, 1534), 511);
+
+// Finally, give it a really long input to trigger fallback from BMH to
+// regular BOYER-MOORE (which has better worst-case complexity).
+
+// Generate a really long Thue-Morse sequence of 'yolo' and 'swag',
+// "yolo swag swag yolo swag yolo yolo swag" ..., goes on for about 5MB.
+// This is hard to search because it all looks similar, but never repeats.
+
+// countBits returns the number of bits in the binary representation of n.
+function countBits(n) {
+  let count;
+  for (count = 0; n > 0; count++) {
+    n = n & (n - 1); // remove top bit
+  }
+  return count;
+}
+const parts = [];
+for (let i = 0; i < 1000000; i++) {
+  parts.push((countBits(i) % 2 === 0) ? 'yolo' : 'swag');
+}
+const reallyLong = Buffer.from(parts.join(' '));
+assert.strictEqual(reallyLong.slice(0, 19).toString(), 'yolo swag swag yolo');
+
+// Expensive reverse searches. Stress test lastIndexOf:
+pattern = reallyLong.slice(0, 100000);  // First 1/50th of the pattern.
+assert.strictEqual(reallyLong.lastIndexOf(pattern), 4751360);
+assert.strictEqual(reallyLong.lastIndexOf(pattern, 4000000), 3932160);
+assert.strictEqual(reallyLong.lastIndexOf(pattern, 3000000), 2949120);
+pattern = reallyLong.slice(100000, 200000);  // Second 1/50th.
+assert.strictEqual(reallyLong.lastIndexOf(pattern), 4728480);
+pattern = reallyLong.slice(0, 1000000);  // First 1/5th.
+assert.strictEqual(reallyLong.lastIndexOf(pattern), 3932160);
+pattern = reallyLong.slice(0, 2000000);  // first 2/5ths.
+assert.strictEqual(reallyLong.lastIndexOf(pattern), 0);
+
+// Test truncation of Number arguments to uint8
+{
+  const buf = Buffer.from('this is a test');
+  assert.strictEqual(buf.indexOf(0x6973), 3);
+  assert.strictEqual(buf.indexOf(0x697320), 4);
+  assert.strictEqual(buf.indexOf(0x69732069), 2);
+  assert.strictEqual(buf.indexOf(0x697374657374), 0);
+  assert.strictEqual(buf.indexOf(0x69737374), 0);
+  assert.strictEqual(buf.indexOf(0x69737465), 11);
+  assert.strictEqual(buf.indexOf(0x69737465), 11);
+  assert.strictEqual(buf.indexOf(-140), 0);
+  assert.strictEqual(buf.indexOf(-152), 1);
+  assert.strictEqual(buf.indexOf(0xff), -1);
+  assert.strictEqual(buf.indexOf(0xffff), -1);
+}
+
+// Test that Uint8Array arguments are okay.
+{
+  const needle = new Uint8Array([ 0x66, 0x6f, 0x6f ]);
+  const haystack = Buffer.from('a foo b foo');
+  assert.strictEqual(haystack.indexOf(needle), 2);
+  assert.strictEqual(haystack.lastIndexOf(needle), haystack.length - 3);
+}
+
+// Avoid abort because of invalid usage
+// see https://github.com/nodejs/node/issues/32753
+// {
+//   assert.throws(() => {
+//     const buffer = require('buffer');
+//     new buffer.Buffer.prototype.lastIndexOf(1, 'str');
+//   }, {
+//     code: 'ERR_INVALID_ARG_TYPE',
+//     name: 'TypeError',
+//     message: 'The "buffer" argument must be an instance of Buffer, ' +
+//              'TypedArray, or DataView. ' +
+//              'Received an instance of lastIndexOf'
+//   });
+// }
diff --git a/test/js/node/test/parallel/test-buffer-new.js b/test/js/node/test/parallel/test-buffer-new.js
new file mode 100644
index 00000000000000..7c840e3de7a6ea
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-new.js
@@ -0,0 +1,10 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+
+assert.throws(() => new Buffer(42, 'utf8'), {
+  code: 'ERR_INVALID_ARG_TYPE',
+  name: 'TypeError',
+  message: 'The "string" argument must be of type string. Received type number (42)'
+});
diff --git a/test/js/node/test/parallel/test-buffer-read.js b/test/js/node/test/parallel/test-buffer-read.js
new file mode 100644
index 00000000000000..212a05a6afbede
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-read.js
@@ -0,0 +1,106 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+// Testing basic buffer read functions
+const buf = Buffer.from([0xa4, 0xfd, 0x48, 0xea, 0xcf, 0xff, 0xd9, 0x01, 0xde]);
+
+function read(buff, funx, args, expected) {
+  assert.strictEqual(buff[funx](...args), expected);
+  assert.throws(
+    () => buff[funx](-1, args[1]),
+    { name: 'RangeError', code: 'ERR_OUT_OF_RANGE' }
+  );
+}
+
+// Testing basic functionality of readDoubleBE() and readDoubleLE()
+read(buf, 'readDoubleBE', [1], -3.1827727774563287e+295);
+read(buf, 'readDoubleLE', [1], -6.966010051009108e+144);
+
+// Testing basic functionality of readFloatBE() and readFloatLE()
+read(buf, 'readFloatBE', [1], -1.6691549692541768e+37);
+read(buf, 'readFloatLE', [1], -7861303808);
+
+// Testing basic functionality of readInt8()
+read(buf, 'readInt8', [1], -3);
+
+// Testing basic functionality of readInt16BE() and readInt16LE()
+read(buf, 'readInt16BE', [1], -696);
+read(buf, 'readInt16LE', [1], 0x48fd);
+
+// Testing basic functionality of readInt32BE() and readInt32LE()
+read(buf, 'readInt32BE', [1], -45552945);
+read(buf, 'readInt32LE', [1], -806729475);
+
+// Testing basic functionality of readIntBE() and readIntLE()
+read(buf, 'readIntBE', [1, 1], -3);
+read(buf, 'readIntLE', [2, 1], 0x48);
+
+// Testing basic functionality of readUInt8()
+read(buf, 'readUInt8', [1], 0xfd);
+
+// Testing basic functionality of readUInt16BE() and readUInt16LE()
+read(buf, 'readUInt16BE', [2], 0x48ea);
+read(buf, 'readUInt16LE', [2], 0xea48);
+
+// Testing basic functionality of readUInt32BE() and readUInt32LE()
+read(buf, 'readUInt32BE', [1], 0xfd48eacf);
+read(buf, 'readUInt32LE', [1], 0xcfea48fd);
+
+// Testing basic functionality of readUIntBE() and readUIntLE()
+read(buf, 'readUIntBE', [2, 2], 0x48ea);
+read(buf, 'readUIntLE', [2, 2], 0xea48);
+
+// Error name and message
+const OOR_ERROR =
+{
+  name: 'RangeError'
+};
+
+const OOB_ERROR =
+{
+  name: 'RangeError',
+  message: 'Attempt to access memory outside buffer bounds'
+};
+
+// Attempt to overflow buffers, similar to previous bug in array buffers
+assert.throws(
+  () => Buffer.allocUnsafe(8).readFloatBE(0xffffffff), OOR_ERROR);
+
+assert.throws(
+  () => Buffer.allocUnsafe(8).readFloatLE(0xffffffff), OOR_ERROR);
+
+// Ensure negative values can't get past offset
+assert.throws(
+  () => Buffer.allocUnsafe(8).readFloatBE(-1), OOR_ERROR);
+assert.throws(
+  () => Buffer.allocUnsafe(8).readFloatLE(-1), OOR_ERROR);
+
+// Offset checks
+{
+  const buf = Buffer.allocUnsafe(0);
+
+  assert.throws(
+    () => buf.readUInt8(0), OOB_ERROR);
+  assert.throws(
+    () => buf.readInt8(0), OOB_ERROR);
+}
+
+[16, 32].forEach((bit) => {
+  const buf = Buffer.allocUnsafe(bit / 8 - 1);
+  [`Int${bit}B`, `Int${bit}L`, `UInt${bit}B`, `UInt${bit}L`].forEach((fn) => {
+    assert.throws(
+      () => buf[`read${fn}E`](0), OOB_ERROR);
+  });
+});
+
+[16, 32].forEach((bits) => {
+  const buf = Buffer.from([0xFF, 0xFF, 0xFF, 0xFF]);
+  ['LE', 'BE'].forEach((endian) => {
+    assert.strictEqual(buf[`readUInt${bits}${endian}`](0),
+                       (0xFFFFFFFF >>> (32 - bits)));
+
+    assert.strictEqual(buf[`readInt${bits}${endian}`](0),
+                       (0xFFFFFFFF >> (32 - bits)));
+  });
+});
diff --git a/test/js/node/test/parallel/test-buffer-readdouble.js b/test/js/node/test/parallel/test-buffer-readdouble.js
new file mode 100644
index 00000000000000..9ddaec30cb1a98
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-readdouble.js
@@ -0,0 +1,148 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+
+// Test (64 bit) double
+const buffer = Buffer.allocUnsafe(8);
+
+buffer[0] = 0x55;
+buffer[1] = 0x55;
+buffer[2] = 0x55;
+buffer[3] = 0x55;
+buffer[4] = 0x55;
+buffer[5] = 0x55;
+buffer[6] = 0xd5;
+buffer[7] = 0x3f;
+assert.strictEqual(buffer.readDoubleBE(0), 1.1945305291680097e+103);
+assert.strictEqual(buffer.readDoubleLE(0), 0.3333333333333333);
+
+buffer[0] = 1;
+buffer[1] = 0;
+buffer[2] = 0;
+buffer[3] = 0;
+buffer[4] = 0;
+buffer[5] = 0;
+buffer[6] = 0xf0;
+buffer[7] = 0x3f;
+assert.strictEqual(buffer.readDoubleBE(0), 7.291122019655968e-304);
+assert.strictEqual(buffer.readDoubleLE(0), 1.0000000000000002);
+
+buffer[0] = 2;
+assert.strictEqual(buffer.readDoubleBE(0), 4.778309726801735e-299);
+assert.strictEqual(buffer.readDoubleLE(0), 1.0000000000000004);
+
+buffer[0] = 1;
+buffer[6] = 0;
+buffer[7] = 0;
+// eslint-disable-next-line no-loss-of-precision
+assert.strictEqual(buffer.readDoubleBE(0), 7.291122019556398e-304);
+assert.strictEqual(buffer.readDoubleLE(0), 5e-324);
+
+buffer[0] = 0xff;
+buffer[1] = 0xff;
+buffer[2] = 0xff;
+buffer[3] = 0xff;
+buffer[4] = 0xff;
+buffer[5] = 0xff;
+buffer[6] = 0x0f;
+buffer[7] = 0x00;
+assert.ok(Number.isNaN(buffer.readDoubleBE(0)));
+assert.strictEqual(buffer.readDoubleLE(0), 2.225073858507201e-308);
+
+buffer[6] = 0xef;
+buffer[7] = 0x7f;
+assert.ok(Number.isNaN(buffer.readDoubleBE(0)));
+assert.strictEqual(buffer.readDoubleLE(0), 1.7976931348623157e+308);
+
+buffer[0] = 0;
+buffer[1] = 0;
+buffer[2] = 0;
+buffer[3] = 0;
+buffer[4] = 0;
+buffer[5] = 0;
+buffer[6] = 0xf0;
+buffer[7] = 0x3f;
+assert.strictEqual(buffer.readDoubleBE(0), 3.03865e-319);
+assert.strictEqual(buffer.readDoubleLE(0), 1);
+
+buffer[6] = 0;
+buffer[7] = 0x40;
+assert.strictEqual(buffer.readDoubleBE(0), 3.16e-322);
+assert.strictEqual(buffer.readDoubleLE(0), 2);
+
+buffer[7] = 0xc0;
+assert.strictEqual(buffer.readDoubleBE(0), 9.5e-322);
+assert.strictEqual(buffer.readDoubleLE(0), -2);
+
+buffer[6] = 0x10;
+buffer[7] = 0;
+assert.strictEqual(buffer.readDoubleBE(0), 2.0237e-320);
+assert.strictEqual(buffer.readDoubleLE(0), 2.2250738585072014e-308);
+
+buffer[6] = 0;
+assert.strictEqual(buffer.readDoubleBE(0), 0);
+assert.strictEqual(buffer.readDoubleLE(0), 0);
+assert.ok(1 / buffer.readDoubleLE(0) >= 0);
+
+buffer[7] = 0x80;
+assert.strictEqual(buffer.readDoubleBE(0), 6.3e-322);
+assert.strictEqual(buffer.readDoubleLE(0), -0);
+assert.ok(1 / buffer.readDoubleLE(0) < 0);
+
+buffer[6] = 0xf0;
+buffer[7] = 0x7f;
+assert.strictEqual(buffer.readDoubleBE(0), 3.0418e-319);
+assert.strictEqual(buffer.readDoubleLE(0), Infinity);
+
+buffer[7] = 0xff;
+assert.strictEqual(buffer.readDoubleBE(0), 3.04814e-319);
+assert.strictEqual(buffer.readDoubleLE(0), -Infinity);
+
+['readDoubleLE', 'readDoubleBE'].forEach((fn) => {
+
+  // Verify that default offset works fine.
+  buffer[fn](undefined);
+  buffer[fn]();
+
+  ['', '0', null, {}, [], () => {}, true, false].forEach((off) => {
+    assert.throws(
+      () => buffer[fn](off),
+      {
+        name: 'TypeError',
+        code: 'ERR_INVALID_ARG_TYPE',
+        message: `The "offset" argument must be of type number.${common.invalidArgTypeHelper(off)}`,
+      }
+    );
+  });
+
+  [-1, 1].forEach((offset) => {
+    assert.throws(
+      () => buffer[fn](offset),
+      {
+        code: 'ERR_OUT_OF_RANGE',
+        name: 'RangeError',
+        message: 'The value of "offset" is out of range. ' +
+                 `It must be >= 0 and <= 0. Received ${offset}`
+      });
+  });
+
+  assert.throws(
+    () => Buffer.alloc(1)[fn](1),
+    {
+      code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+      name: 'RangeError',
+      message: 'Attempt to access memory outside buffer bounds'
+    });
+
+  [Infinity, NaN, 1.01].forEach((offset) => {
+    assert.throws(
+      () => buffer[fn](offset),
+      {
+        code: 'ERR_OUT_OF_RANGE',
+        name: 'RangeError',
+        message: 'The value of "offset" is out of range. ' +
+                 `It must be an integer. Received ${offset}`
+      });
+  });
+});
diff --git a/test/js/node/test/parallel/test-buffer-readfloat.js b/test/js/node/test/parallel/test-buffer-readfloat.js
new file mode 100644
index 00000000000000..a78a912185eb35
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-readfloat.js
@@ -0,0 +1,110 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+
+// Test 32 bit float
+const buffer = Buffer.alloc(4);
+
+buffer[0] = 0;
+buffer[1] = 0;
+buffer[2] = 0x80;
+buffer[3] = 0x3f;
+assert.strictEqual(buffer.readFloatBE(0), 4.600602988224807e-41);
+assert.strictEqual(buffer.readFloatLE(0), 1);
+
+buffer[0] = 0;
+buffer[1] = 0;
+buffer[2] = 0;
+buffer[3] = 0xc0;
+assert.strictEqual(buffer.readFloatBE(0), 2.6904930515036488e-43);
+assert.strictEqual(buffer.readFloatLE(0), -2);
+
+buffer[0] = 0xff;
+buffer[1] = 0xff;
+buffer[2] = 0x7f;
+buffer[3] = 0x7f;
+assert.ok(Number.isNaN(buffer.readFloatBE(0)));
+assert.strictEqual(buffer.readFloatLE(0), 3.4028234663852886e+38);
+
+buffer[0] = 0xab;
+buffer[1] = 0xaa;
+buffer[2] = 0xaa;
+buffer[3] = 0x3e;
+assert.strictEqual(buffer.readFloatBE(0), -1.2126478207002966e-12);
+assert.strictEqual(buffer.readFloatLE(0), 0.3333333432674408);
+
+buffer[0] = 0;
+buffer[1] = 0;
+buffer[2] = 0;
+buffer[3] = 0;
+assert.strictEqual(buffer.readFloatBE(0), 0);
+assert.strictEqual(buffer.readFloatLE(0), 0);
+assert.ok(1 / buffer.readFloatLE(0) >= 0);
+
+buffer[3] = 0x80;
+assert.strictEqual(buffer.readFloatBE(0), 1.793662034335766e-43);
+assert.strictEqual(buffer.readFloatLE(0), -0);
+assert.ok(1 / buffer.readFloatLE(0) < 0);
+
+buffer[0] = 0;
+buffer[1] = 0;
+buffer[2] = 0x80;
+buffer[3] = 0x7f;
+assert.strictEqual(buffer.readFloatBE(0), 4.609571298396486e-41);
+assert.strictEqual(buffer.readFloatLE(0), Infinity);
+
+buffer[0] = 0;
+buffer[1] = 0;
+buffer[2] = 0x80;
+buffer[3] = 0xff;
+assert.strictEqual(buffer.readFloatBE(0), 4.627507918739843e-41);
+assert.strictEqual(buffer.readFloatLE(0), -Infinity);
+
+['readFloatLE', 'readFloatBE'].forEach((fn) => {
+
+  // Verify that default offset works fine.
+  buffer[fn](undefined);
+  buffer[fn]();
+
+  ['', '0', null, {}, [], () => {}, true, false].forEach((off) => {
+    assert.throws(
+      () => buffer[fn](off),
+      {
+        name: 'TypeError',
+        code: 'ERR_INVALID_ARG_TYPE',
+        message: `The "offset" argument must be of type number.${common.invalidArgTypeHelper(off)}`,
+      }
+    );
+  });
+
+  [-1, 1].forEach((offset) => {
+    assert.throws(
+      () => buffer[fn](offset),
+      {
+        code: 'ERR_OUT_OF_RANGE',
+        name: 'RangeError',
+        message: 'The value of "offset" is out of range. ' +
+                 `It must be >= 0 and <= 0. Received ${offset}`
+      });
+  });
+
+  assert.throws(
+    () => Buffer.alloc(1)[fn](1),
+    {
+      code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+      name: 'RangeError',
+      message: 'Attempt to access memory outside buffer bounds'
+    });
+
+  [Infinity, NaN, 1.01].forEach((offset) => {
+    assert.throws(
+      () => buffer[fn](offset),
+      {
+        code: 'ERR_OUT_OF_RANGE',
+        name: 'RangeError',
+        message: 'The value of "offset" is out of range. ' +
+                 `It must be an integer. Received ${offset}`
+      });
+  });
+});
diff --git a/test/js/node/test/parallel/test-buffer-readint.js b/test/js/node/test/parallel/test-buffer-readint.js
new file mode 100644
index 00000000000000..89d9a9456a9703
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-readint.js
@@ -0,0 +1,198 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+
+// Test OOB
+{
+  const buffer = Buffer.alloc(4);
+
+  ['Int8', 'Int16BE', 'Int16LE', 'Int32BE', 'Int32LE'].forEach((fn) => {
+
+    // Verify that default offset works fine.
+    buffer[`read${fn}`](undefined);
+    buffer[`read${fn}`]();
+
+    ['', '0', null, {}, [], () => {}, true, false].forEach((o) => {
+      assert.throws(
+        () => buffer[`read${fn}`](o),
+        {
+          code: 'ERR_INVALID_ARG_TYPE',
+          name: 'TypeError',
+          message: `The "offset" argument must be of type number.${common.invalidArgTypeHelper(o)}`,
+        });
+    });
+
+    [Infinity, -1, -4294967295].forEach((offset) => {
+      assert.throws(
+        () => buffer[`read${fn}`](offset),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError'
+        });
+    });
+
+    [NaN, 1.01].forEach((offset) => {
+      assert.throws(
+        () => buffer[`read${fn}`](offset),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "offset" is out of range. ' +
+                   `It must be an integer. Received ${offset}`
+        });
+    });
+  });
+}
+
+// Test 8 bit signed integers
+{
+  const data = Buffer.from([0x23, 0xab, 0x7c, 0xef]);
+
+  assert.strictEqual(data.readInt8(0), 0x23);
+
+  data[0] = 0xff;
+  assert.strictEqual(data.readInt8(0), -1);
+
+  data[0] = 0x87;
+  assert.strictEqual(data.readInt8(0), -121);
+  assert.strictEqual(data.readInt8(1), -85);
+  assert.strictEqual(data.readInt8(2), 124);
+  assert.strictEqual(data.readInt8(3), -17);
+}
+
+// Test 16 bit integers
+{
+  const buffer = Buffer.from([0x16, 0x79, 0x65, 0x6e, 0x69, 0x78]);
+
+  assert.strictEqual(buffer.readInt16BE(0), 0x1679);
+  assert.strictEqual(buffer.readInt16LE(0), 0x7916);
+
+  buffer[0] = 0xff;
+  buffer[1] = 0x80;
+  assert.strictEqual(buffer.readInt16BE(0), -128);
+  assert.strictEqual(buffer.readInt16LE(0), -32513);
+
+  buffer[0] = 0x77;
+  buffer[1] = 0x65;
+  assert.strictEqual(buffer.readInt16BE(0), 0x7765);
+  assert.strictEqual(buffer.readInt16BE(1), 0x6565);
+  assert.strictEqual(buffer.readInt16BE(2), 0x656e);
+  assert.strictEqual(buffer.readInt16BE(3), 0x6e69);
+  assert.strictEqual(buffer.readInt16BE(4), 0x6978);
+  assert.strictEqual(buffer.readInt16LE(0), 0x6577);
+  assert.strictEqual(buffer.readInt16LE(1), 0x6565);
+  assert.strictEqual(buffer.readInt16LE(2), 0x6e65);
+  assert.strictEqual(buffer.readInt16LE(3), 0x696e);
+  assert.strictEqual(buffer.readInt16LE(4), 0x7869);
+}
+
+// Test 32 bit integers
+{
+  const buffer = Buffer.from([0x43, 0x53, 0x16, 0x79, 0x36, 0x17]);
+
+  assert.strictEqual(buffer.readInt32BE(0), 0x43531679);
+  assert.strictEqual(buffer.readInt32LE(0), 0x79165343);
+
+  buffer[0] = 0xff;
+  buffer[1] = 0xfe;
+  buffer[2] = 0xef;
+  buffer[3] = 0xfa;
+  assert.strictEqual(buffer.readInt32BE(0), -69638);
+  assert.strictEqual(buffer.readInt32LE(0), -84934913);
+
+  buffer[0] = 0x42;
+  buffer[1] = 0xc3;
+  buffer[2] = 0x95;
+  buffer[3] = 0xa9;
+  assert.strictEqual(buffer.readInt32BE(0), 0x42c395a9);
+  assert.strictEqual(buffer.readInt32BE(1), -1013601994);
+  assert.strictEqual(buffer.readInt32BE(2), -1784072681);
+  assert.strictEqual(buffer.readInt32LE(0), -1449802942);
+  assert.strictEqual(buffer.readInt32LE(1), 917083587);
+  assert.strictEqual(buffer.readInt32LE(2), 389458325);
+}
+
+// Test Int
+{
+  const buffer = Buffer.from([0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08]);
+
+  assert.strictEqual(buffer.readIntLE(0, 1), 0x01);
+  assert.strictEqual(buffer.readIntBE(0, 1), 0x01);
+  assert.strictEqual(buffer.readIntLE(0, 3), 0x030201);
+  assert.strictEqual(buffer.readIntBE(0, 3), 0x010203);
+  assert.strictEqual(buffer.readIntLE(0, 5), 0x0504030201);
+  assert.strictEqual(buffer.readIntBE(0, 5), 0x0102030405);
+  assert.strictEqual(buffer.readIntLE(0, 6), 0x060504030201);
+  assert.strictEqual(buffer.readIntBE(0, 6), 0x010203040506);
+  assert.strictEqual(buffer.readIntLE(1, 6), 0x070605040302);
+  assert.strictEqual(buffer.readIntBE(1, 6), 0x020304050607);
+  assert.strictEqual(buffer.readIntLE(2, 6), 0x080706050403);
+  assert.strictEqual(buffer.readIntBE(2, 6), 0x030405060708);
+
+  // Check byteLength.
+  ['readIntBE', 'readIntLE'].forEach((fn) => {
+    ['', '0', null, {}, [], () => {}, true, false, undefined].forEach((len) => {
+      assert.throws(
+        () => buffer[fn](0, len),
+        { code: 'ERR_INVALID_ARG_TYPE' });
+    });
+
+    [Infinity, -1].forEach((byteLength) => {
+      assert.throws(
+        () => buffer[fn](0, byteLength),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          message: 'The value of "byteLength" is out of range. ' +
+                   `It must be >= 1 and <= 6. Received ${byteLength}`
+        });
+    });
+
+    [NaN, 1.01].forEach((byteLength) => {
+      assert.throws(
+        () => buffer[fn](0, byteLength),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "byteLength" is out of range. ' +
+                   `It must be an integer. Received ${byteLength}`
+        });
+    });
+  });
+
+  // Test 1 to 6 bytes.
+  for (let i = 1; i <= 6; i++) {
+    ['readIntBE', 'readIntLE'].forEach((fn) => {
+      ['', '0', null, {}, [], () => {}, true, false, undefined].forEach((o) => {
+        assert.throws(
+          () => buffer[fn](o, i),
+          {
+            code: 'ERR_INVALID_ARG_TYPE',
+            name: 'TypeError'
+          });
+      });
+
+      [-1, -4294967295].forEach((offset) => {
+        assert.throws(
+          () => buffer[fn](offset, i),
+          {
+            code: 'ERR_OUT_OF_RANGE',
+            name: 'RangeError',
+            message: 'The value of "offset" is out of range. ' +
+                     `It must be >= 0 and <= ${8 - i}. Received ${offset}`
+          });
+      });
+
+      [Infinity, NaN, 1.01].forEach((offset) => {
+        assert.throws(
+          () => buffer[fn](offset, i),
+          {
+            code: 'ERR_OUT_OF_RANGE',
+            name: 'RangeError',
+            message: 'The value of "offset" is out of range. ' +
+                     `It must be an integer. Received ${offset}`
+          });
+      });
+    });
+  }
+}
diff --git a/test/js/node/test/parallel/test-buffer-readuint.js b/test/js/node/test/parallel/test-buffer-readuint.js
new file mode 100644
index 00000000000000..3c0e1f549413c7
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-readuint.js
@@ -0,0 +1,168 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+const common = require('../common');
+
+// Test OOB
+{
+  const buffer = Buffer.alloc(4);
+
+  ['UInt8', 'UInt16BE', 'UInt16LE', 'UInt32BE', 'UInt32LE'].forEach((fn) => {
+
+    // Verify that default offset works fine.
+    buffer[`read${fn}`](undefined);
+    buffer[`read${fn}`]();
+
+    ['', '0', null, {}, [], () => {}, true, false].forEach((o) => {
+      assert.throws(
+        () => buffer[`read${fn}`](o),
+        {
+          code: 'ERR_INVALID_ARG_TYPE',
+          name: 'TypeError',
+          message: `The "offset" argument must be of type number.${common.invalidArgTypeHelper(o)}`,
+        });
+    });
+
+    [Infinity, -1, -4294967295].forEach((offset) => {
+      assert.throws(
+        () => buffer[`read${fn}`](offset),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+        });
+    });
+
+    [NaN, 1.01].forEach((offset) => {
+      assert.throws(
+        () => buffer[`read${fn}`](offset),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "offset" is out of range. ' +
+                   `It must be an integer. Received ${offset}`
+        });
+    });
+  });
+}
+
+// Test 8 bit unsigned integers
+{
+  const data = Buffer.from([0xff, 0x2a, 0x2a, 0x2a]);
+  assert.strictEqual(data.readUInt8(0), 255);
+  assert.strictEqual(data.readUInt8(1), 42);
+  assert.strictEqual(data.readUInt8(2), 42);
+  assert.strictEqual(data.readUInt8(3), 42);
+}
+
+// Test 16 bit unsigned integers
+{
+  const data = Buffer.from([0x00, 0x2a, 0x42, 0x3f]);
+  assert.strictEqual(data.readUInt16BE(0), 0x2a);
+  assert.strictEqual(data.readUInt16BE(1), 0x2a42);
+  assert.strictEqual(data.readUInt16BE(2), 0x423f);
+  assert.strictEqual(data.readUInt16LE(0), 0x2a00);
+  assert.strictEqual(data.readUInt16LE(1), 0x422a);
+  assert.strictEqual(data.readUInt16LE(2), 0x3f42);
+
+  data[0] = 0xfe;
+  data[1] = 0xfe;
+  assert.strictEqual(data.readUInt16BE(0), 0xfefe);
+  assert.strictEqual(data.readUInt16LE(0), 0xfefe);
+}
+
+// Test 32 bit unsigned integers
+{
+  const data = Buffer.from([0x32, 0x65, 0x42, 0x56, 0x23, 0xff]);
+  assert.strictEqual(data.readUInt32BE(0), 0x32654256);
+  assert.strictEqual(data.readUInt32BE(1), 0x65425623);
+  assert.strictEqual(data.readUInt32BE(2), 0x425623ff);
+  assert.strictEqual(data.readUInt32LE(0), 0x56426532);
+  assert.strictEqual(data.readUInt32LE(1), 0x23564265);
+  assert.strictEqual(data.readUInt32LE(2), 0xff235642);
+}
+
+// Test UInt
+{
+  const buffer = Buffer.from([0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08]);
+
+  assert.strictEqual(buffer.readUIntLE(0, 1), 0x01);
+  assert.strictEqual(buffer.readUIntBE(0, 1), 0x01);
+  assert.strictEqual(buffer.readUIntLE(0, 3), 0x030201);
+  assert.strictEqual(buffer.readUIntBE(0, 3), 0x010203);
+  assert.strictEqual(buffer.readUIntLE(0, 5), 0x0504030201);
+  assert.strictEqual(buffer.readUIntBE(0, 5), 0x0102030405);
+  assert.strictEqual(buffer.readUIntLE(0, 6), 0x060504030201);
+  assert.strictEqual(buffer.readUIntBE(0, 6), 0x010203040506);
+  assert.strictEqual(buffer.readUIntLE(1, 6), 0x070605040302);
+  assert.strictEqual(buffer.readUIntBE(1, 6), 0x020304050607);
+  assert.strictEqual(buffer.readUIntLE(2, 6), 0x080706050403);
+  assert.strictEqual(buffer.readUIntBE(2, 6), 0x030405060708);
+
+  // Check byteLength.
+  ['readUIntBE', 'readUIntLE'].forEach((fn) => {
+    ['', '0', null, {}, [], () => {}, true, false, undefined].forEach((len) => {
+      assert.throws(
+        () => buffer[fn](0, len),
+        { code: 'ERR_INVALID_ARG_TYPE' });
+    });
+
+    [Infinity, -1].forEach((byteLength) => {
+      assert.throws(
+        () => buffer[fn](0, byteLength),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          message: 'The value of "byteLength" is out of range. ' +
+                   `It must be >= 1 and <= 6. Received ${byteLength}`
+        });
+    });
+
+    [NaN, 1.01].forEach((byteLength) => {
+      assert.throws(
+        () => buffer[fn](0, byteLength),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "byteLength" is out of range. ' +
+                   `It must be an integer. Received ${byteLength}`
+        });
+    });
+  });
+
+  // Test 1 to 6 bytes.
+  for (let i = 1; i <= 6; i++) {
+    ['readUIntBE', 'readUIntLE'].forEach((fn) => {
+      ['', '0', null, {}, [], () => {}, true, false, undefined].forEach((o) => {
+        assert.throws(
+          () => buffer[fn](o, i),
+          {
+            code: 'ERR_INVALID_ARG_TYPE',
+            name: 'TypeError',
+            message: `The "offset" argument must be of type number.${common.invalidArgTypeHelper(o)}`,
+          });
+      });
+
+      [-1, -4294967295].forEach((offset) => {
+        assert.throws(
+          () => buffer[fn](offset, i),
+          {
+            code: 'ERR_OUT_OF_RANGE',
+            name: 'RangeError',
+            message: 'The value of "offset" is out of range. ' +
+                     `It must be >= 0 and <= ${8 - i}. Received ${offset}`
+          });
+      });
+
+      [Infinity, NaN, 1.01].forEach((offset) => {
+        assert.throws(
+          () => buffer[fn](offset, i),
+          {
+            code: 'ERR_OUT_OF_RANGE',
+            name: 'RangeError',
+            message: 'The value of "offset" is out of range. ' +
+                     `It must be an integer. Received ${offset}`
+          });
+      });
+    });
+  }
+}
diff --git a/test/js/node/test/parallel/test-buffer-sharedarraybuffer.js b/test/js/node/test/parallel/test-buffer-sharedarraybuffer.js
new file mode 100644
index 00000000000000..79678f268572a2
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-sharedarraybuffer.js
@@ -0,0 +1,27 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+
+const sab = new SharedArrayBuffer(24);
+const arr1 = new Uint16Array(sab);
+const arr2 = new Uint16Array(12);
+arr2[0] = 5000;
+arr1[0] = 5000;
+arr1[1] = 4000;
+arr2[1] = 4000;
+
+const arr_buf = Buffer.from(arr1.buffer);
+const ar_buf = Buffer.from(arr2.buffer);
+
+assert.deepStrictEqual(arr_buf, ar_buf);
+
+arr1[1] = 6000;
+arr2[1] = 6000;
+
+assert.deepStrictEqual(arr_buf, ar_buf);
+
+// Checks for calling Buffer.byteLength on a SharedArrayBuffer.
+assert.strictEqual(Buffer.byteLength(sab), sab.byteLength);
+
+Buffer.from({ buffer: sab }); // Should not throw.
diff --git a/test/js/node/test/parallel/test-buffer-write.js b/test/js/node/test/parallel/test-buffer-write.js
new file mode 100644
index 00000000000000..c834b6ee8ff71a
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-write.js
@@ -0,0 +1,108 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+
+[-1, 10].forEach((offset) => {
+  assert.throws(
+    () => Buffer.alloc(9).write('foo', offset),
+    {
+      code: 'ERR_OUT_OF_RANGE',
+      name: 'RangeError',
+      message: 'The value of "offset" is out of range. ' +
+               `It must be >= 0 and <= 9. Received ${offset}`
+    }
+  );
+});
+
+const resultMap = new Map([
+  ['utf8', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['ucs2', Buffer.from([102, 0, 111, 0, 111, 0, 0, 0, 0])],
+  ['ascii', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['latin1', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['binary', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['utf16le', Buffer.from([102, 0, 111, 0, 111, 0, 0, 0, 0])],
+  ['base64', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['base64url', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+  ['hex', Buffer.from([102, 111, 111, 0, 0, 0, 0, 0, 0])],
+]);
+
+// utf8, ucs2, ascii, latin1, utf16le
+const encodings = ['utf8', 'utf-8', 'ucs2', 'ucs-2', 'ascii', 'latin1',
+                   'binary', 'utf16le', 'utf-16le'];
+
+encodings
+  .reduce((es, e) => es.concat(e, e.toUpperCase()), [])
+  .forEach((encoding) => {
+    const buf = Buffer.alloc(9);
+    const len = Buffer.byteLength('foo', encoding);
+    assert.strictEqual(buf.write('foo', 0, len, encoding), len);
+
+    if (encoding.includes('-'))
+      encoding = encoding.replace('-', '');
+
+    assert.deepStrictEqual(buf, resultMap.get(encoding.toLowerCase()));
+  });
+
+// base64
+['base64', 'BASE64', 'base64url', 'BASE64URL'].forEach((encoding) => {
+  const buf = Buffer.alloc(9);
+  const len = Buffer.byteLength('Zm9v', encoding);
+
+  assert.strictEqual(buf.write('Zm9v', 0, len, encoding), len);
+  assert.deepStrictEqual(buf, resultMap.get(encoding.toLowerCase()));
+});
+
+// hex
+['hex', 'HEX'].forEach((encoding) => {
+  const buf = Buffer.alloc(9);
+  const len = Buffer.byteLength('666f6f', encoding);
+
+  assert.strictEqual(buf.write('666f6f', 0, len, encoding), len);
+  assert.deepStrictEqual(buf, resultMap.get(encoding.toLowerCase()));
+});
+
+// Invalid encodings
+for (let i = 1; i < 10; i++) {
+  const encoding = String(i).repeat(i);
+  const error = common.expectsError({
+    code: 'ERR_UNKNOWN_ENCODING',
+    name: 'TypeError',
+    message: `Unknown encoding: ${encoding}`
+  });
+
+  assert.ok(!Buffer.isEncoding(encoding));
+  assert.throws(() => Buffer.alloc(9).write('foo', encoding), error);
+}
+
+// UCS-2 overflow CVE-2018-12115
+for (let i = 1; i < 4; i++) {
+  // Allocate two Buffers sequentially off the pool. Run more than once in case
+  // we hit the end of the pool and don't get sequential allocations
+  const x = Buffer.allocUnsafe(4).fill(0);
+  const y = Buffer.allocUnsafe(4).fill(1);
+  // Should not write anything, pos 3 doesn't have enough room for a 16-bit char
+  assert.strictEqual(x.write('ыыыыыы', 3, 'ucs2'), 0);
+  // CVE-2018-12115 experienced via buffer overrun to next block in the pool
+  assert.strictEqual(Buffer.compare(y, Buffer.alloc(4, 1)), 0);
+}
+
+// Should not write any data when there is no space for 16-bit chars
+const z = Buffer.alloc(4, 0);
+assert.strictEqual(z.write('\u0001', 3, 'ucs2'), 0);
+assert.strictEqual(Buffer.compare(z, Buffer.alloc(4, 0)), 0);
+// Make sure longer strings are written up to the buffer end.
+assert.strictEqual(z.write('abcd', 2), 2);
+assert.deepStrictEqual([...z], [0, 0, 0x61, 0x62]);
+
+// Large overrun could corrupt the process
+assert.strictEqual(Buffer.alloc(4)
+  .write('ыыыыыы'.repeat(100), 3, 'utf16le'), 0);
+
+{
+  // .write() does not affect the byte after the written-to slice of the Buffer.
+  // Refs: https://github.com/nodejs/node/issues/26422
+  const buf = Buffer.alloc(8);
+  assert.strictEqual(buf.write('ыы', 1, 'utf16le'), 4);
+  assert.deepStrictEqual([...buf], [0, 0x4b, 0x04, 0x4b, 0x04, 0, 0, 0]);
+}
diff --git a/test/js/node/test/parallel/test-buffer-writedouble.js b/test/js/node/test/parallel/test-buffer-writedouble.js
new file mode 100644
index 00000000000000..5026c8187430b3
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-writedouble.js
@@ -0,0 +1,133 @@
+'use strict';
+
+// Tests to verify doubles are correctly written
+
+require('../common');
+const assert = require('assert');
+
+const buffer = Buffer.allocUnsafe(16);
+
+buffer.writeDoubleBE(2.225073858507201e-308, 0);
+buffer.writeDoubleLE(2.225073858507201e-308, 8);
+assert.ok(buffer.equals(new Uint8Array([
+  0x00, 0x0f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x0f, 0x00,
+])));
+
+buffer.writeDoubleBE(1.0000000000000004, 0);
+buffer.writeDoubleLE(1.0000000000000004, 8);
+assert.ok(buffer.equals(new Uint8Array([
+  0x3f, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02,
+  0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf0, 0x3f,
+])));
+
+buffer.writeDoubleBE(-2, 0);
+buffer.writeDoubleLE(-2, 8);
+assert.ok(buffer.equals(new Uint8Array([
+  0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xc0,
+])));
+
+buffer.writeDoubleBE(1.7976931348623157e+308, 0);
+buffer.writeDoubleLE(1.7976931348623157e+308, 8);
+assert.ok(buffer.equals(new Uint8Array([
+  0x7f, 0xef, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xef, 0x7f,
+])));
+
+buffer.writeDoubleBE(0 * -1, 0);
+buffer.writeDoubleLE(0 * -1, 8);
+assert.ok(buffer.equals(new Uint8Array([
+  0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80,
+])));
+
+buffer.writeDoubleBE(Infinity, 0);
+buffer.writeDoubleLE(Infinity, 8);
+
+assert.ok(buffer.equals(new Uint8Array([
+  0x7F, 0xF0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xF0, 0x7F,
+])));
+
+assert.strictEqual(buffer.readDoubleBE(0), Infinity);
+assert.strictEqual(buffer.readDoubleLE(8), Infinity);
+
+buffer.writeDoubleBE(-Infinity, 0);
+buffer.writeDoubleLE(-Infinity, 8);
+
+assert.ok(buffer.equals(new Uint8Array([
+  0xFF, 0xF0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xF0, 0xFF,
+])));
+
+assert.strictEqual(buffer.readDoubleBE(0), -Infinity);
+assert.strictEqual(buffer.readDoubleLE(8), -Infinity);
+
+buffer.writeDoubleBE(NaN, 0);
+buffer.writeDoubleLE(NaN, 8);
+
+// JS only knows a single NaN but there exist two platform specific
+// implementations. Therefore, allow both quiet and signalling NaNs.
+if (buffer[1] === 0xF7) {
+  assert.ok(buffer.equals(new Uint8Array([
+    0x7F, 0xF7, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xF7, 0x7F,
+  ])));
+} else {
+  assert.ok(buffer.equals(new Uint8Array([
+    0x7F, 0xF8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xF8, 0x7F,
+  ])));
+}
+
+assert.ok(Number.isNaN(buffer.readDoubleBE(0)));
+assert.ok(Number.isNaN(buffer.readDoubleLE(8)));
+
+// OOB in writeDouble{LE,BE} should throw.
+{
+  const small = Buffer.allocUnsafe(1);
+
+  ['writeDoubleLE', 'writeDoubleBE'].forEach((fn) => {
+
+    // Verify that default offset works fine.
+    buffer[fn](23, undefined);
+    buffer[fn](23);
+
+    assert.throws(
+      () => small[fn](11.11, 0),
+      {
+        code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+        name: 'RangeError',
+        message: 'Attempt to access memory outside buffer bounds'
+      });
+
+    ['', '0', null, {}, [], () => {}, true, false].forEach((off) => {
+      assert.throws(
+        () => small[fn](23, off),
+        { code: 'ERR_INVALID_ARG_TYPE' });
+    });
+
+    [Infinity, -1, 9].forEach((offset) => {
+      assert.throws(
+        () => buffer[fn](23, offset),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "offset" is out of range. ' +
+                     `It must be >= 0 and <= 8. Received ${offset}`
+        });
+    });
+
+    [NaN, 1.01].forEach((offset) => {
+      assert.throws(
+        () => buffer[fn](42, offset),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "offset" is out of range. ' +
+                   `It must be an integer. Received ${offset}`
+        });
+    });
+  });
+}
diff --git a/test/js/node/test/parallel/test-buffer-writefloat.js b/test/js/node/test/parallel/test-buffer-writefloat.js
new file mode 100644
index 00000000000000..8676a819fc776d
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-writefloat.js
@@ -0,0 +1,117 @@
+'use strict';
+
+// Tests to verify floats are correctly written
+
+require('../common');
+const assert = require('assert');
+
+const buffer = Buffer.allocUnsafe(8);
+
+buffer.writeFloatBE(1, 0);
+buffer.writeFloatLE(1, 4);
+assert.ok(buffer.equals(
+  new Uint8Array([ 0x3f, 0x80, 0x00, 0x00, 0x00, 0x00, 0x80, 0x3f ])));
+
+buffer.writeFloatBE(1 / 3, 0);
+buffer.writeFloatLE(1 / 3, 4);
+assert.ok(buffer.equals(
+  new Uint8Array([ 0x3e, 0xaa, 0xaa, 0xab, 0xab, 0xaa, 0xaa, 0x3e ])));
+
+buffer.writeFloatBE(3.4028234663852886e+38, 0);
+buffer.writeFloatLE(3.4028234663852886e+38, 4);
+assert.ok(buffer.equals(
+  new Uint8Array([ 0x7f, 0x7f, 0xff, 0xff, 0xff, 0xff, 0x7f, 0x7f ])));
+
+buffer.writeFloatLE(1.1754943508222875e-38, 0);
+buffer.writeFloatBE(1.1754943508222875e-38, 4);
+assert.ok(buffer.equals(
+  new Uint8Array([ 0x00, 0x00, 0x80, 0x00, 0x00, 0x80, 0x00, 0x00 ])));
+
+buffer.writeFloatBE(0 * -1, 0);
+buffer.writeFloatLE(0 * -1, 4);
+assert.ok(buffer.equals(
+  new Uint8Array([ 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80 ])));
+
+buffer.writeFloatBE(Infinity, 0);
+buffer.writeFloatLE(Infinity, 4);
+assert.ok(buffer.equals(
+  new Uint8Array([ 0x7F, 0x80, 0x00, 0x00, 0x00, 0x00, 0x80, 0x7F ])));
+
+assert.strictEqual(buffer.readFloatBE(0), Infinity);
+assert.strictEqual(buffer.readFloatLE(4), Infinity);
+
+buffer.writeFloatBE(-Infinity, 0);
+buffer.writeFloatLE(-Infinity, 4);
+assert.ok(buffer.equals(
+  new Uint8Array([ 0xFF, 0x80, 0x00, 0x00, 0x00, 0x00, 0x80, 0xFF ])));
+
+assert.strictEqual(buffer.readFloatBE(0), -Infinity);
+assert.strictEqual(buffer.readFloatLE(4), -Infinity);
+
+buffer.writeFloatBE(NaN, 0);
+buffer.writeFloatLE(NaN, 4);
+
+// JS only knows a single NaN but there exist two platform specific
+// implementations. Therefore, allow both quiet and signalling NaNs.
+if (buffer[1] === 0xBF) {
+  assert.ok(
+    buffer.equals(new Uint8Array(
+      [ 0x7F, 0xBF, 0xFF, 0xFF, 0xFF, 0xFF, 0xBF, 0x7F ])));
+} else {
+  assert.ok(
+    buffer.equals(new Uint8Array(
+      [ 0x7F, 0xC0, 0x00, 0x00, 0x00, 0x00, 0xC0, 0x7F ])));
+}
+
+assert.ok(Number.isNaN(buffer.readFloatBE(0)));
+assert.ok(Number.isNaN(buffer.readFloatLE(4)));
+
+// OOB in writeFloat{LE,BE} should throw.
+{
+  const small = Buffer.allocUnsafe(1);
+
+  ['writeFloatLE', 'writeFloatBE'].forEach((fn) => {
+
+    // Verify that default offset works fine.
+    buffer[fn](23, undefined);
+    buffer[fn](23);
+
+    assert.throws(
+      () => small[fn](11.11, 0),
+      {
+        code: 'ERR_BUFFER_OUT_OF_BOUNDS',
+        name: 'RangeError',
+        message: 'Attempt to access memory outside buffer bounds'
+      });
+
+    ['', '0', null, {}, [], () => {}, true, false].forEach((off) => {
+      assert.throws(
+        () => small[fn](23, off),
+        { code: 'ERR_INVALID_ARG_TYPE' }
+      );
+    });
+
+    [Infinity, -1, 5].forEach((offset) => {
+      assert.throws(
+        () => buffer[fn](23, offset),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "offset" is out of range. ' +
+                   `It must be >= 0 and <= 4. Received ${offset}`
+        }
+      );
+    });
+
+    [NaN, 1.01].forEach((offset) => {
+      assert.throws(
+        () => buffer[fn](42, offset),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "offset" is out of range. ' +
+                   `It must be an integer. Received ${offset}`
+        });
+    });
+  });
+}
diff --git a/test/js/node/test/parallel/test-buffer-writeint.js b/test/js/node/test/parallel/test-buffer-writeint.js
new file mode 100644
index 00000000000000..5fb0d78268d51b
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-writeint.js
@@ -0,0 +1,268 @@
+'use strict';
+
+// Tests to verify signed integers are correctly written
+
+require('../common');
+const assert = require('assert');
+const errorOutOfBounds = {
+  code: 'ERR_OUT_OF_RANGE',
+  name: 'RangeError',
+  message: new RegExp('^The value of "value" is out of range\\. ' +
+                      'It must be >= -\\d+ and <= \\d+\\. Received .+$')
+};
+
+// Test 8 bit
+{
+  const buffer = Buffer.alloc(2);
+
+  buffer.writeInt8(0x23, 0);
+  buffer.writeInt8(-5, 1);
+  assert.ok(buffer.equals(new Uint8Array([ 0x23, 0xfb ])));
+
+  /* Make sure we handle min/max correctly */
+  buffer.writeInt8(0x7f, 0);
+  buffer.writeInt8(-0x80, 1);
+  assert.ok(buffer.equals(new Uint8Array([ 0x7f, 0x80 ])));
+
+  assert.throws(() => {
+    buffer.writeInt8(0x7f + 1, 0);
+  }, errorOutOfBounds);
+  assert.throws(() => {
+    buffer.writeInt8(-0x80 - 1, 0);
+  }, errorOutOfBounds);
+
+  // Verify that default offset works fine.
+  buffer.writeInt8(23, undefined);
+  buffer.writeInt8(23);
+
+  ['', '0', null, {}, [], () => {}, true, false].forEach((off) => {
+    assert.throws(
+      () => buffer.writeInt8(23, off),
+      { code: 'ERR_INVALID_ARG_TYPE' });
+  });
+
+  [NaN, Infinity, -1, 1.01].forEach((off) => {
+    assert.throws(
+      () => buffer.writeInt8(23, off),
+      { code: 'ERR_OUT_OF_RANGE' });
+  });
+}
+
+// Test 16 bit
+{
+  const buffer = Buffer.alloc(4);
+
+  buffer.writeInt16BE(0x0023, 0);
+  buffer.writeInt16LE(0x0023, 2);
+  assert.ok(buffer.equals(new Uint8Array([ 0x00, 0x23, 0x23, 0x00 ])));
+
+  buffer.writeInt16BE(-5, 0);
+  buffer.writeInt16LE(-5, 2);
+  assert.ok(buffer.equals(new Uint8Array([ 0xff, 0xfb, 0xfb, 0xff ])));
+
+  buffer.writeInt16BE(-1679, 0);
+  buffer.writeInt16LE(-1679, 2);
+  assert.ok(buffer.equals(new Uint8Array([ 0xf9, 0x71, 0x71, 0xf9 ])));
+
+  /* Make sure we handle min/max correctly */
+  buffer.writeInt16BE(0x7fff, 0);
+  buffer.writeInt16BE(-0x8000, 2);
+  assert.ok(buffer.equals(new Uint8Array([ 0x7f, 0xff, 0x80, 0x00 ])));
+
+  buffer.writeInt16LE(0x7fff, 0);
+  buffer.writeInt16LE(-0x8000, 2);
+  assert.ok(buffer.equals(new Uint8Array([ 0xff, 0x7f, 0x00, 0x80 ])));
+
+  ['writeInt16BE', 'writeInt16LE'].forEach((fn) => {
+
+    // Verify that default offset works fine.
+    buffer[fn](23, undefined);
+    buffer[fn](23);
+
+    assert.throws(() => {
+      buffer[fn](0x7fff + 1, 0);
+    }, errorOutOfBounds);
+    assert.throws(() => {
+      buffer[fn](-0x8000 - 1, 0);
+    }, errorOutOfBounds);
+
+    ['', '0', null, {}, [], () => {}, true, false].forEach((off) => {
+      assert.throws(
+        () => buffer[fn](23, off),
+        { code: 'ERR_INVALID_ARG_TYPE' });
+    });
+
+    [NaN, Infinity, -1, 1.01].forEach((off) => {
+      assert.throws(
+        () => buffer[fn](23, off),
+        { code: 'ERR_OUT_OF_RANGE' });
+    });
+  });
+}
+
+// Test 32 bit
+{
+  const buffer = Buffer.alloc(8);
+
+  buffer.writeInt32BE(0x23, 0);
+  buffer.writeInt32LE(0x23, 4);
+  assert.ok(buffer.equals(new Uint8Array([
+    0x00, 0x00, 0x00, 0x23, 0x23, 0x00, 0x00, 0x00,
+  ])));
+
+  buffer.writeInt32BE(-5, 0);
+  buffer.writeInt32LE(-5, 4);
+  assert.ok(buffer.equals(new Uint8Array([
+    0xff, 0xff, 0xff, 0xfb, 0xfb, 0xff, 0xff, 0xff,
+  ])));
+
+  buffer.writeInt32BE(-805306713, 0);
+  buffer.writeInt32LE(-805306713, 4);
+  assert.ok(buffer.equals(new Uint8Array([
+    0xcf, 0xff, 0xfe, 0xa7, 0xa7, 0xfe, 0xff, 0xcf,
+  ])));
+
+  /* Make sure we handle min/max correctly */
+  buffer.writeInt32BE(0x7fffffff, 0);
+  buffer.writeInt32BE(-0x80000000, 4);
+  assert.ok(buffer.equals(new Uint8Array([
+    0x7f, 0xff, 0xff, 0xff, 0x80, 0x00, 0x00, 0x00,
+  ])));
+
+  buffer.writeInt32LE(0x7fffffff, 0);
+  buffer.writeInt32LE(-0x80000000, 4);
+  assert.ok(buffer.equals(new Uint8Array([
+    0xff, 0xff, 0xff, 0x7f, 0x00, 0x00, 0x00, 0x80,
+  ])));
+
+  ['writeInt32BE', 'writeInt32LE'].forEach((fn) => {
+
+    // Verify that default offset works fine.
+    buffer[fn](23, undefined);
+    buffer[fn](23);
+
+    assert.throws(() => {
+      buffer[fn](0x7fffffff + 1, 0);
+    }, errorOutOfBounds);
+    assert.throws(() => {
+      buffer[fn](-0x80000000 - 1, 0);
+    }, errorOutOfBounds);
+
+    ['', '0', null, {}, [], () => {}, true, false].forEach((off) => {
+      assert.throws(
+        () => buffer[fn](23, off),
+        { code: 'ERR_INVALID_ARG_TYPE' });
+    });
+
+    [NaN, Infinity, -1, 1.01].forEach((off) => {
+      assert.throws(
+        () => buffer[fn](23, off),
+        { code: 'ERR_OUT_OF_RANGE' });
+    });
+  });
+}
+
+// Test 48 bit
+{
+  const value = 0x1234567890ab;
+  const buffer = Buffer.allocUnsafe(6);
+  buffer.writeIntBE(value, 0, 6);
+  assert.ok(buffer.equals(new Uint8Array([
+    0x12, 0x34, 0x56, 0x78, 0x90, 0xab,
+  ])));
+
+  buffer.writeIntLE(value, 0, 6);
+  assert.ok(buffer.equals(new Uint8Array([
+    0xab, 0x90, 0x78, 0x56, 0x34, 0x12,
+  ])));
+}
+
+// Test Int
+{
+  const data = Buffer.alloc(8);
+
+  // Check byteLength.
+  ['writeIntBE', 'writeIntLE'].forEach((fn) => {
+    ['', '0', null, {}, [], () => {}, true, false, undefined].forEach((bl) => {
+      assert.throws(
+        () => data[fn](23, 0, bl),
+        { code: 'ERR_INVALID_ARG_TYPE' });
+    });
+
+    [Infinity, -1].forEach((byteLength) => {
+      assert.throws(
+        () => data[fn](23, 0, byteLength),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          message: 'The value of "byteLength" is out of range. ' +
+                   `It must be >= 1 and <= 6. Received ${byteLength}`
+        }
+      );
+    });
+
+    [NaN, 1.01].forEach((byteLength) => {
+      assert.throws(
+        () => data[fn](42, 0, byteLength),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "byteLength" is out of range. ' +
+                   `It must be an integer. Received ${byteLength}`
+        });
+    });
+  });
+
+  // Test 1 to 6 bytes.
+  for (let i = 1; i <= 6; i++) {
+    ['writeIntBE', 'writeIntLE'].forEach((fn) => {
+      const min = -(2 ** (i * 8 - 1));
+      const max = 2 ** (i * 8 - 1) - 1;
+      let range = `>= ${min} and <= ${max}`;
+      if (i > 4) {
+        range = `>= -(2 ** ${i * 8 - 1}) and < 2 ** ${i * 8 - 1}`;
+      }
+      [min - 1, max + 1].forEach((val) => {
+        const received = String(val);
+        assert.throws(() => {
+          data[fn](val, 0, i);
+        }, {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "value" is out of range. ' +
+                   `It must be ${range}. Received ${received}`
+        });
+      });
+
+      ['', '0', null, {}, [], () => {}, true, false, undefined].forEach((o) => {
+        assert.throws(
+          () => data[fn](min, o, i),
+          {
+            code: 'ERR_INVALID_ARG_TYPE',
+            name: 'TypeError'
+          });
+      });
+
+      [Infinity, -1, -4294967295].forEach((offset) => {
+        assert.throws(
+          () => data[fn](min, offset, i),
+          {
+            code: 'ERR_OUT_OF_RANGE',
+            name: 'RangeError',
+            message: 'The value of "offset" is out of range. ' +
+                     `It must be >= 0 and <= ${8 - i}. Received ${offset}`
+          });
+      });
+
+      [NaN, 1.01].forEach((offset) => {
+        assert.throws(
+          () => data[fn](max, offset, i),
+          {
+            code: 'ERR_OUT_OF_RANGE',
+            name: 'RangeError',
+            message: 'The value of "offset" is out of range. ' +
+                     `It must be an integer. Received ${offset}`
+          });
+      });
+    });
+  }
+}
diff --git a/test/js/node/test/parallel/test-buffer-writeuint.js b/test/js/node/test/parallel/test-buffer-writeuint.js
new file mode 100644
index 00000000000000..6416973d3b554a
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-writeuint.js
@@ -0,0 +1,234 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+const common = require('../common');
+
+// We need to check the following things:
+//  - We are correctly resolving big endian (doesn't mean anything for 8 bit)
+//  - Correctly resolving little endian (doesn't mean anything for 8 bit)
+//  - Correctly using the offsets
+//  - Correctly interpreting values that are beyond the signed range as unsigned
+
+{ // OOB
+  const data = Buffer.alloc(8);
+  ['UInt8', 'UInt16BE', 'UInt16LE', 'UInt32BE', 'UInt32LE'].forEach((fn) => {
+
+    // Verify that default offset works fine.
+    data[`write${fn}`](23, undefined);
+    data[`write${fn}`](23);
+
+    ['', '0', null, {}, [], () => {}, true, false].forEach((o) => {
+      assert.throws(
+        () => data[`write${fn}`](23, o),
+        {
+          code: 'ERR_INVALID_ARG_TYPE',
+          message: `The "offset" argument must be of type number.${common.invalidArgTypeHelper(o)}`,
+        });
+    });
+
+    [NaN, Infinity, -1, 1.01].forEach((o) => {
+      assert.throws(
+        () => data[`write${fn}`](23, o),
+        { code: 'ERR_OUT_OF_RANGE' });
+    });
+  });
+}
+
+{ // Test 8 bit
+  const data = Buffer.alloc(4);
+
+  data.writeUInt8(23, 0);
+  data.writeUInt8(23, 1);
+  data.writeUInt8(23, 2);
+  data.writeUInt8(23, 3);
+  assert.ok(data.equals(new Uint8Array([23, 23, 23, 23])));
+
+  data.writeUInt8(23, 0);
+  data.writeUInt8(23, 1);
+  data.writeUInt8(23, 2);
+  data.writeUInt8(23, 3);
+  assert.ok(data.equals(new Uint8Array([23, 23, 23, 23])));
+
+  data.writeUInt8(255, 0);
+  assert.strictEqual(data[0], 255);
+
+  data.writeUInt8(255, 0);
+  assert.strictEqual(data[0], 255);
+}
+
+// Test 16 bit
+{
+  let value = 0x2343;
+  const data = Buffer.alloc(4);
+
+  data.writeUInt16BE(value, 0);
+  assert.ok(data.equals(new Uint8Array([0x23, 0x43, 0, 0])));
+
+  data.writeUInt16BE(value, 1);
+  assert.ok(data.equals(new Uint8Array([0x23, 0x23, 0x43, 0])));
+
+  data.writeUInt16BE(value, 2);
+  assert.ok(data.equals(new Uint8Array([0x23, 0x23, 0x23, 0x43])));
+
+  data.writeUInt16LE(value, 0);
+  assert.ok(data.equals(new Uint8Array([0x43, 0x23, 0x23, 0x43])));
+
+  data.writeUInt16LE(value, 1);
+  assert.ok(data.equals(new Uint8Array([0x43, 0x43, 0x23, 0x43])));
+
+  data.writeUInt16LE(value, 2);
+  assert.ok(data.equals(new Uint8Array([0x43, 0x43, 0x43, 0x23])));
+
+  value = 0xff80;
+  data.writeUInt16LE(value, 0);
+  assert.ok(data.equals(new Uint8Array([0x80, 0xff, 0x43, 0x23])));
+
+  data.writeUInt16BE(value, 0);
+  assert.ok(data.equals(new Uint8Array([0xff, 0x80, 0x43, 0x23])));
+
+  value = 0xfffff;
+  ['writeUInt16BE', 'writeUInt16LE'].forEach((fn) => {
+    assert.throws(
+      () => data[fn](value, 0),
+      {
+        code: 'ERR_OUT_OF_RANGE',
+        message: 'The value of "value" is out of range. ' +
+                 `It must be >= 0 and <= 65535. Received ${value}`
+      }
+    );
+  });
+}
+
+// Test 32 bit
+{
+  const data = Buffer.alloc(6);
+  const value = 0xe7f90a6d;
+
+  data.writeUInt32BE(value, 0);
+  assert.ok(data.equals(new Uint8Array([0xe7, 0xf9, 0x0a, 0x6d, 0, 0])));
+
+  data.writeUInt32BE(value, 1);
+  assert.ok(data.equals(new Uint8Array([0xe7, 0xe7, 0xf9, 0x0a, 0x6d, 0])));
+
+  data.writeUInt32BE(value, 2);
+  assert.ok(data.equals(new Uint8Array([0xe7, 0xe7, 0xe7, 0xf9, 0x0a, 0x6d])));
+
+  data.writeUInt32LE(value, 0);
+  assert.ok(data.equals(new Uint8Array([0x6d, 0x0a, 0xf9, 0xe7, 0x0a, 0x6d])));
+
+  data.writeUInt32LE(value, 1);
+  assert.ok(data.equals(new Uint8Array([0x6d, 0x6d, 0x0a, 0xf9, 0xe7, 0x6d])));
+
+  data.writeUInt32LE(value, 2);
+  assert.ok(data.equals(new Uint8Array([0x6d, 0x6d, 0x6d, 0x0a, 0xf9, 0xe7])));
+}
+
+// Test 48 bit
+{
+  const value = 0x1234567890ab;
+  const data = Buffer.allocUnsafe(6);
+  data.writeUIntBE(value, 0, 6);
+  assert.ok(data.equals(new Uint8Array([0x12, 0x34, 0x56, 0x78, 0x90, 0xab])));
+
+  data.writeUIntLE(value, 0, 6);
+  assert.ok(data.equals(new Uint8Array([0xab, 0x90, 0x78, 0x56, 0x34, 0x12])));
+}
+
+// Test UInt
+{
+  const data = Buffer.alloc(8);
+  let val = 0x100;
+
+  // Check byteLength.
+  ['writeUIntBE', 'writeUIntLE'].forEach((fn) => {
+    ['', '0', null, {}, [], () => {}, true, false, undefined].forEach((bl) => {
+      assert.throws(
+        () => data[fn](23, 0, bl),
+        {
+          code: 'ERR_INVALID_ARG_TYPE',
+        });
+    });
+
+    [Infinity, -1].forEach((byteLength) => {
+      assert.throws(
+        () => data[fn](23, 0, byteLength),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          message: 'The value of "byteLength" is out of range. ' +
+                   `It must be >= 1 and <= 6. Received ${byteLength}`
+        }
+      );
+    });
+
+    [NaN, 1.01].forEach((byteLength) => {
+      assert.throws(
+        () => data[fn](42, 0, byteLength),
+        {
+          code: 'ERR_OUT_OF_RANGE',
+          name: 'RangeError',
+          message: 'The value of "byteLength" is out of range. ' +
+                   `It must be an integer. Received ${byteLength}`
+        });
+    });
+  });
+
+  // Test 1 to 6 bytes.
+  for (let i = 1; i <= 6; i++) {
+    const range = i < 5 ? `= ${val - 1}` : ` 2 ** ${i * 8}`;
+    const received = String(val);
+    ['writeUIntBE', 'writeUIntLE'].forEach((fn) => {
+      assert.throws(() => {
+        data[fn](val, 0, i);
+      }, {
+        code: 'ERR_OUT_OF_RANGE',
+        name: 'RangeError',
+        message: 'The value of "value" is out of range. ' +
+                 `It must be >= 0 and <${range}. Received ${received}`
+      });
+
+      ['', '0', null, {}, [], () => {}, true, false].forEach((o) => {
+        assert.throws(
+          () => data[fn](23, o, i),
+          {
+            code: 'ERR_INVALID_ARG_TYPE',
+            name: 'TypeError'
+          });
+      });
+
+      [Infinity, -1, -4294967295].forEach((offset) => {
+        assert.throws(
+          () => data[fn](val - 1, offset, i),
+          {
+            code: 'ERR_OUT_OF_RANGE',
+            name: 'RangeError',
+            message: 'The value of "offset" is out of range. ' +
+                     `It must be >= 0 and <= ${8 - i}. Received ${offset}`
+          });
+      });
+
+      [NaN, 1.01].forEach((offset) => {
+        assert.throws(
+          () => data[fn](val - 1, offset, i),
+          {
+            code: 'ERR_OUT_OF_RANGE',
+            name: 'RangeError',
+            message: 'The value of "offset" is out of range. ' +
+                     `It must be an integer. Received ${offset}`
+          });
+      });
+    });
+
+    val *= 0x100;
+  }
+}
+
+for (const fn of [
+  'UInt8', 'UInt16LE', 'UInt16BE', 'UInt32LE', 'UInt32BE', 'UIntLE', 'UIntBE',
+  'BigUInt64LE', 'BigUInt64BE',
+]) {
+  const p = Buffer.prototype;
+  const lowerFn = fn.replace(/UInt/, 'Uint');
+  assert.strictEqual(p[`write${fn}`], p[`write${lowerFn}`]);
+  assert.strictEqual(p[`read${fn}`], p[`read${lowerFn}`]);
+}
diff --git a/test/js/node/test/parallel/test-buffer-zero-fill-cli.js b/test/js/node/test/parallel/test-buffer-zero-fill-cli.js
new file mode 100644
index 00000000000000..6c2b6608b197f1
--- /dev/null
+++ b/test/js/node/test/parallel/test-buffer-zero-fill-cli.js
@@ -0,0 +1,32 @@
+'use strict';
+// Flags: --zero-fill-buffers
+
+// when using --zero-fill-buffers, every Buffer and SlowBuffer
+// instance must be zero filled upon creation
+
+require('../common');
+const SlowBuffer = require('buffer').SlowBuffer;
+const assert = require('assert');
+
+function isZeroFilled(buf) {
+  for (const n of buf)
+    if (n > 0) return false;
+  return true;
+}
+
+// This can be somewhat unreliable because the
+// allocated memory might just already happen to
+// contain all zeroes. The test is run multiple
+// times to improve the reliability.
+for (let i = 0; i < 50; i++) {
+  const bufs = [
+    Buffer.alloc(20),
+    Buffer(20),
+    Buffer.allocUnsafe(20),
+    SlowBuffer(20),
+    new SlowBuffer(20),
+  ];
+  for (const buf of bufs) {
+    assert(isZeroFilled(buf));
+  }
+}
diff --git a/test/js/node/test/parallel/test-common-must-not-call.js b/test/js/node/test/parallel/test-common-must-not-call.js
index b3c94a2390ffb6..87e78b1a0ac1da 100644
--- a/test/js/node/test/parallel/test-common-must-not-call.js
+++ b/test/js/node/test/parallel/test-common-must-not-call.js
@@ -22,7 +22,7 @@ const createValidate = (line, args = []) => common.mustCall((e) => {
   const rest = msg.substring(firstColon + 1);
   assert.strictEqual(path.basename(fileName), 'test-common-must-not-call.js');
   const argsInfo = args.length > 0 ?
-    `\ncalled with arguments: ${args.map(util.inspect).join(', ')}` : '';
+    `\ncalled with arguments: ${args.map(v => Bun.inspect(v)).join(', ')}` : '';
   assert.strictEqual(rest, line + argsInfo);
 });