Allow writes to prototypes directly.

skinny85 · Apr 20, 2024 · edc53e2 · edc53e2
1 parent a930017
commit edc53e2
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Showing 3 changed files with 36 additions and 6 deletions.
diff --git a/part-14/src/main/java/com/endoflineblog/truffle/part_13/runtime/InteropDynamicObject.java b/part-14/src/main/java/com/endoflineblog/truffle/part_13/runtime/InteropDynamicObject.java
@@ -42,4 +42,22 @@ Object getMembers(@SuppressWarnings("unused") boolean includeInternal,
             @CachedLibrary("this") DynamicObjectLibrary thisObjectLibrary) {
         return new MemberNamesObject(thisObjectLibrary.getKeyArray(this));
     }
+
+    @ExportMessage
+    boolean isMemberModifiable(String member,
+            @CachedLibrary("this") DynamicObjectLibrary thisObjectLibrary) {
+        return this.isMemberReadable(member, thisObjectLibrary);
+    }
+
+    @ExportMessage
+    boolean isMemberInsertable(String member,
+            @CachedLibrary("this") DynamicObjectLibrary thisObjectLibrary) {
+        return !this.isMemberModifiable(member, thisObjectLibrary);
+    }
+
+    @ExportMessage
+    void writeMember(String member, Object value,
+            @CachedLibrary("this") DynamicObjectLibrary thisObjectLibrary) {
+        thisObjectLibrary.put(this, member, value);
+    }
 }
diff --git a/part-14/src/main/java/com/endoflineblog/truffle/part_13/runtime/JavaScriptObject.java b/part-14/src/main/java/com/endoflineblog/truffle/part_13/runtime/JavaScriptObject.java
@@ -73,10 +73,4 @@ boolean isMemberInsertable(String member,
             @CachedLibrary("this.classPrototypeObject") DynamicObjectLibrary prototypeObjectLibrary) {
         return !this.isMemberModifiable(member, thisObjectLibrary, prototypeObjectLibrary);
     }
-
-    @ExportMessage
-    void writeMember(String member, Object value,
-            @CachedLibrary("this") DynamicObjectLibrary thisObjectLibrary) {
-        thisObjectLibrary.put(this, member, value);
-    }
 }
diff --git a/part-14/src/test/java/com/endoflineblog/truffle/part_13/InheritanceTest.java b/part-14/src/test/java/com/endoflineblog/truffle/part_13/InheritanceTest.java
@@ -179,6 +179,24 @@ void hasOwnProperty_returns_false_for_primitives() {
         assertFalse(result.asBoolean());
     }
 
+    @Test
+    void prototypes_can_be_written_to() {
+        Value result = this.context.eval("ezs", "" +
+                "class Class { " +
+                "    m() { " +
+                "        return 13; " +
+                "    } " +
+                "} " +
+                "function m() { " +
+                "    return 46; " +
+                "} " +
+                "const obj = new Class(); " +
+                "Class.m = m; " +
+                "obj.m(); "
+        );
+        assertEquals(46, result.asInt());
+    }
+
     @Test
     void extending_non_existent_class_is_an_error() {
         try {