diff --git a/.sbtopts b/.sbtopts
new file mode 100644
index 00000000..594985c1
--- /dev/null
+++ b/.sbtopts
@@ -0,0 +1,4 @@
+-J-Xmx4G
+-J-XX:MaxMetaspaceSize=1G
+-J-Dfile.encoding=UTF-8
+-J-Dsbt.io.implicit.relative.glob.conversion=allow
diff --git a/project/BuildHelper.scala b/project/BuildHelper.scala
index 5eb111a4..d84af17d 100644
--- a/project/BuildHelper.scala
+++ b/project/BuildHelper.scala
@@ -80,6 +80,8 @@ object BuildHelper {
   def stdSettings(prjName: String) = Seq(
     name := s"$prjName",
     fork := true,
+    run / baseDirectory := file("."),
+    Test / baseDirectory := file("."),
     crossScalaVersions := Seq(Scala212, Scala213),
     ThisBuild / scalaVersion := Scala213,
     scalacOptions := stdOptions ++ extraOptions(scalaVersion.value),
diff --git a/zio-process/js/src/main/scala/zio/process/CommandPlatformSpecific.scala b/zio-process/js/src/main/scala/zio/process/CommandPlatformSpecific.scala
index 8b8344be..82993926 100644
--- a/zio-process/js/src/main/scala/zio/process/CommandPlatformSpecific.scala
+++ b/zio-process/js/src/main/scala/zio/process/CommandPlatformSpecific.scala
@@ -17,7 +17,7 @@ package zio.process
 
 import FilePlatformSpecific._
 import ProcessPlatformSpecific._
-import zio.{ NonEmptyChunk, ZIO }
+import zio._
 import scala.annotation.nowarn
 import scala.scalajs.js
 import js.JSConverters._
@@ -38,7 +38,7 @@ private[process] trait CommandPlatformSpecific {
       stdinStream <- c.stdin match {
                        case FromStream(stream, _) =>
                          stream.toInputStream.map(Some(_))
-                       case JavaStream(in, _)     => ZIO.succeed(Some(in))
+                       case JavaStream(in, _)     => ZIO.some(in)
                        case _                     => ZIO.none
                      }
       promise     <- ZIO.attempt {
@@ -97,7 +97,11 @@ private[process] trait CommandPlatformSpecific {
                                  process.stdin.write(new js.typedarray.Uint8Array(arr.take(read).map(_.toShort).toJSArray))
                                )
                              else if (read == -1)
-                               if (process.stdin != null) if (!process.stdin.writableEnded) { process.stdin.end(); () }
+                               if (process.stdin != null && !process.stdin.writableEnded) {
+                                 process.stdin.end()
+                                 ()
+                               }
+
                            }
 
                            write(true)
@@ -113,7 +117,10 @@ private[process] trait CommandPlatformSpecific {
                                    "end",
                                    { () =>
                                      connectStdin(s)
-                                     if (process.stdin != null) if (!process.stdin.writableEnded) process.stdin.end()
+
+                                     if (process.stdin != null && !process.stdin.writableEnded)
+                                       process.stdin.end()
+
                                      resolve(zioProcess)
                                    }
                                  )
@@ -122,7 +129,9 @@ private[process] trait CommandPlatformSpecific {
                              process.on("spawn", () => connectStdin(s))
                              in.on(
                                "end",
-                               () => if (process.stdin != null) if (!process.stdin.writableEnded) process.stdin.end()
+                               () =>
+                                 if (process.stdin != null && !process.stdin.writableEnded)
+                                   process.stdin.end()
                              )
                              val node = js.Dynamic.global.require("process")
                              process.on("spawn", () => node.nextTick(() => resolve(zioProcess)))
diff --git a/zio-process/js/src/main/scala/zio/process/Constructors.scala b/zio-process/js/src/main/scala/zio/process/Constructors.scala
index 49f6ad9e..c7ef1a05 100644
--- a/zio-process/js/src/main/scala/zio/process/Constructors.scala
+++ b/zio-process/js/src/main/scala/zio/process/Constructors.scala
@@ -20,10 +20,13 @@ import zio.stream.ZStream
 
 import java.io.OutputStream
 import zio.Trace
+
 import java.io.IOException
 import zio.ZIO
 import zio.Chunk
 import zio.Scope
+import zio.process.ProcessPlatformSpecific.JProcess
+
 import java.io.InputStream
 
 private[process] object Constructors {
@@ -52,19 +55,14 @@ private[process] object Constructors {
             val bytes = byteChunk.toArray
             out.write(bytes)
             bytesWritten + bytes.length
-          }.refineOrDie { case e: IOException =>
-            e
-          }
+          }.refineToOrDie[IOException]
         }
       }
     }
 
   def zsink(outputStream: OutputStream): ZSink[Any, IOException, Byte, Byte, Long] = fromOutputStream(outputStream)
 
-  /**
-   * Creates a stream from a `java.io.InputStream`
-   */
-  def fromInputStream(
+  def fromProcessInputStream(process: JProcess)(
     is: => InputStream,
     chunkSize: => Int = ZStream.DefaultChunkSize
   )(implicit trace: Trace): ZStream[Any, IOException, Byte] =
@@ -73,8 +71,10 @@ private[process] object Constructors {
         for {
           bufArray  <- ZIO.succeed(Array.ofDim[Byte](chunkSize))
           bytesRead <- ZIO
-                         .attemptBlockingCancelable(is.read(bufArray))(ZIO.succeed(is.close()))
-                         .refineToOrDie[java.io.IOException]
+                         .attemptBlockingCancelable(is.read(bufArray))(
+                           ZIO.succeed(is.close()).ensuring(ZIO.attemptBlocking(process.kill()).ignore)
+                         )
+                         .refineToOrDie[IOException]
                          .asSomeError
           bytes     <- if (bytesRead < 0)
                          ZIO.fail(None)
diff --git a/zio-process/js/src/main/scala/zio/process/FilePlatformSpecific.scala b/zio-process/js/src/main/scala/zio/process/FilePlatformSpecific.scala
index a1bca67f..651b7d7e 100644
--- a/zio-process/js/src/main/scala/zio/process/FilePlatformSpecific.scala
+++ b/zio-process/js/src/main/scala/zio/process/FilePlatformSpecific.scala
@@ -6,6 +6,8 @@ private[process] object FilePlatformSpecific {
   type File = String
   type Path = String
 
+  def fileOf(file: String): File = file
+
   def getAbsolute(file: File): js.Any = {
     val path   = js.Dynamic.global.require("path")
     val nodejs = js.Dynamic.global.require("process")
diff --git a/zio-process/js/src/main/scala/zio/process/ProcessInput.scala b/zio-process/js/src/main/scala/zio/process/ProcessInput.scala
index 7df1800b..19f8ecd1 100644
--- a/zio-process/js/src/main/scala/zio/process/ProcessInput.scala
+++ b/zio-process/js/src/main/scala/zio/process/ProcessInput.scala
@@ -16,7 +16,7 @@
 package zio.process
 
 import zio.stream.ZStream
-import zio.{ Chunk, Queue }
+import zio._
 import FilePlatformSpecific._
 import java.io.ByteArrayInputStream
 import java.nio.charset.{ Charset, StandardCharsets }
@@ -41,7 +41,7 @@ object ProcessInput {
     ProcessInput.JavaStream(
       ProcessPlatformSpecific.JSInputStream(
         fs.createReadStream(FilePlatformSpecific.getAbsolute(file)).asInstanceOf[JS.Readable],
-        true
+        pause = true
       ),
       flushChunksEagerly = false
     )
diff --git a/zio-process/js/src/main/scala/zio/process/ProcessPlatformSpecific.scala b/zio-process/js/src/main/scala/zio/process/ProcessPlatformSpecific.scala
index 2efba4df..8edd9a07 100644
--- a/zio-process/js/src/main/scala/zio/process/ProcessPlatformSpecific.scala
+++ b/zio-process/js/src/main/scala/zio/process/ProcessPlatformSpecific.scala
@@ -15,12 +15,11 @@
  */
 package zio.process
 
-import zio.ZIO
+import zio._
 
 import java.io.{ InputStream, OutputStream }
 import scala.scalajs.js.typedarray.Uint8Array
 import scala.scalajs.js
-import zio.Chunk
 import js.JSConverters._
 
 private[process] trait ProcessPlatformSpecific extends ProcessInterface { self: Process =>
@@ -29,7 +28,13 @@ private[process] trait ProcessPlatformSpecific extends ProcessInterface { self:
 
   private var killed = false
 
-  protected def waitForUnsafe: Int = self.process.exitCode
+  def waitFor: IO[CommandError, ExitCode] =
+    ProcessPlatformSpecific.wait(stdoutInternal).map(_ => ExitCode(self.process.exitCode)).refineOrDie {
+      case CommandThrowable.IOError(e) => e
+    }
+
+  protected def waitForUnsafe: Int =
+    self.process.exitCode
 
   protected def isAliveUnsafe: Boolean = !killed
   protected def destroyUnsafe(): Unit = {
@@ -139,6 +144,7 @@ private[process] object ProcessPlatformSpecific {
       }
 
     }
+
     override def readAllBytes(): Array[Byte] = {
       val arr = buffer.toArray
       buffer = Chunk.empty
diff --git a/zio-process/js/src/test/bash/both-streams-test.sh b/zio-process/js/src/test/bash/both-streams-test.sh
deleted file mode 100644
index 8d264927..00000000
--- a/zio-process/js/src/test/bash/both-streams-test.sh
+++ /dev/null
@@ -1,9 +0,0 @@
-#!/bin/bash
-
-echoerr() { echo "$@" 1>&2; }
-
-echo "stdout1"
-echoerr "stderr1"
-
-echo "stdout2"
-echoerr "stderr2"
\ No newline at end of file
diff --git a/zio-process/js/src/test/bash/echo-repeat.sh b/zio-process/js/src/test/bash/echo-repeat.sh
deleted file mode 100644
index 19d9a657..00000000
--- a/zio-process/js/src/test/bash/echo-repeat.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/bash
-
-for i in {1..60}; do echo "iteration: $i"; sleep 1; done
\ No newline at end of file
diff --git a/zio-process/js/src/test/bash/kill-test/sample-child.sh b/zio-process/js/src/test/bash/kill-test/sample-child.sh
deleted file mode 100644
index 4670b77b..00000000
--- a/zio-process/js/src/test/bash/kill-test/sample-child.sh
+++ /dev/null
@@ -1,5 +0,0 @@
-#!/bin/bash
-echo $$
-sleep 30
-echo -n "end: "
-echo $$
diff --git a/zio-process/js/src/test/bash/kill-test/sample-parent.sh b/zio-process/js/src/test/bash/kill-test/sample-parent.sh
deleted file mode 100644
index 6b21bc13..00000000
--- a/zio-process/js/src/test/bash/kill-test/sample-parent.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-echo $$
-./sample-child.sh &
-./sample-child.sh &
-sleep 30
-echo -n "end: "
-echo $$
\ No newline at end of file
diff --git a/zio-process/js/src/test/bash/no-permissions.sh b/zio-process/js/src/test/bash/no-permissions.sh
deleted file mode 100644
index b2d6f2c3..00000000
--- a/zio-process/js/src/test/bash/no-permissions.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/bash
-
-echo "this should not run because it doesn't have execute permissions"
diff --git a/zio-process/js/src/test/bash/stdin-echo.sh b/zio-process/js/src/test/bash/stdin-echo.sh
deleted file mode 100644
index 0de47dae..00000000
--- a/zio-process/js/src/test/bash/stdin-echo.sh
+++ /dev/null
@@ -1,6 +0,0 @@
-#!/bin/bash
-
-while read line
-do
-  echo "$line"
-done
\ No newline at end of file
diff --git a/zio-process/js/src/test/scala/zio/process/SpecProperties.scala b/zio-process/js/src/test/scala/zio/process/SpecProperties.scala
deleted file mode 100644
index a3359df5..00000000
--- a/zio-process/js/src/test/scala/zio/process/SpecProperties.scala
+++ /dev/null
@@ -1,9 +0,0 @@
-package zio.process
-
-trait SpecProperties {
-  val dir = "zio-process/shared/"
-
-  import FilePlatformSpecific._
-  def mkFile(file: String): File = file
-
-}
diff --git a/zio-process/jvm/src/main/scala/zio/process/Constructors.scala b/zio-process/jvm/src/main/scala/zio/process/Constructors.scala
index a8fc9fa5..1840161a 100644
--- a/zio-process/jvm/src/main/scala/zio/process/Constructors.scala
+++ b/zio-process/jvm/src/main/scala/zio/process/Constructors.scala
@@ -15,24 +15,42 @@
  */
 package zio.process
 
+import zio.process.ProcessPlatformSpecific.JProcess
 import zio.stream.ZSink
 import zio.stream.ZStream
 
 import java.io.OutputStream
 import java.io.InputStream
-import zio.Trace
+import zio._
+
 import java.io.IOException
 
 private[process] object Constructors {
 
   def zsink(outputStream: OutputStream) = ZSink.fromOutputStream(outputStream)
 
-  /**
-   * Creates a stream from a `java.io.InputStream`
-   */
-  def fromInputStream(
+  def fromProcessInputStream(process: JProcess)(
     is: => InputStream,
     chunkSize: => Int = ZStream.DefaultChunkSize
-  )(implicit trace: Trace): ZStream[Any, IOException, Byte] = ZStream.fromInputStream(is, chunkSize)
+  )(implicit trace: Trace): ZStream[Any, IOException, Byte] =
+    ZStream.succeed((is, chunkSize)).flatMap { case (is, chunkSize) =>
+      ZStream.repeatZIOChunkOption {
+        for {
+          bufArray  <- ZIO.succeed(Array.ofDim[Byte](chunkSize))
+          bytesRead <- ZIO
+                         .attemptBlockingCancelable(is.read(bufArray))(ZIO.attemptBlocking(process.destroy()).ignore)
+                         .refineToOrDie[IOException]
+                         .asSomeError
+          bytes     <- if (bytesRead < 0)
+                         ZIO.fail(None)
+                       else if (bytesRead == 0)
+                         ZIO.succeed(Chunk.empty)
+                       else if (bytesRead < chunkSize)
+                         ZIO.succeed(Chunk.fromArray(bufArray).take(bytesRead))
+                       else
+                         ZIO.succeed(Chunk.fromArray(bufArray))
+        } yield bytes
+      }
+    }
 
 }
diff --git a/zio-process/jvm/src/main/scala/zio/process/FilePlatformSpecific.scala b/zio-process/jvm/src/main/scala/zio/process/FilePlatformSpecific.scala
index 40269003..e6c1968f 100644
--- a/zio-process/jvm/src/main/scala/zio/process/FilePlatformSpecific.scala
+++ b/zio-process/jvm/src/main/scala/zio/process/FilePlatformSpecific.scala
@@ -1,7 +1,9 @@
 package zio.process
 
-object FilePlatformSpecific {
+private[process] object FilePlatformSpecific {
   type File = java.io.File
 
-  def exists(file: File) = file.exists()
+  def fileOf(file: String): File = new File(file)
+
+  def exists(file: File): Boolean = file.exists()
 }
diff --git a/zio-process/jvm/src/main/scala/zio/process/ProcessInput.scala b/zio-process/jvm/src/main/scala/zio/process/ProcessInput.scala
index 9ac4cdd0..5f6ecc6a 100644
--- a/zio-process/jvm/src/main/scala/zio/process/ProcessInput.scala
+++ b/zio-process/jvm/src/main/scala/zio/process/ProcessInput.scala
@@ -16,7 +16,7 @@
 package zio.process
 
 import zio.stream.ZStream
-import zio.{ Chunk, Queue }
+import zio._
 
 import java.io.ByteArrayInputStream
 import java.nio.charset.{ Charset, StandardCharsets }
diff --git a/zio-process/jvm/src/main/scala/zio/process/ProcessPlatformSpecific.scala b/zio-process/jvm/src/main/scala/zio/process/ProcessPlatformSpecific.scala
index fab230dd..290c29b8 100644
--- a/zio-process/jvm/src/main/scala/zio/process/ProcessPlatformSpecific.scala
+++ b/zio-process/jvm/src/main/scala/zio/process/ProcessPlatformSpecific.scala
@@ -18,17 +18,27 @@ package zio.process
 import java.io.InputStream
 import java.io.OutputStream
 import scala.jdk.CollectionConverters._
-import zio.ZIO
+import zio._
+
 import scala.annotation.nowarn
 
 private[process] trait ProcessPlatformSpecific { self: Process =>
 
   import ProcessPlatformSpecific._
 
-  protected def waitForUnsafe: Int = self.process.waitFor()
+  protected def waitFor: IO[CommandError, ExitCode] =
+    ZIO
+      .fromCompletableFuture(self.process.onExit())
+      .map(x => ExitCode(x.exitValue()))
+      .onInterrupt(ZIO.attemptBlocking(self.destroyUnsafe()).ignore)
+      .refineOrDie { case CommandThrowable.IOError(e) => e }
+
+  protected def waitForUnsafe: Int                  = self.process.waitFor()
+
+  protected def isAliveUnsafe: Boolean = self.process.isAlive()
+
+  protected def destroyUnsafe(): Unit = self.process.destroy()
 
-  protected def isAliveUnsafe: Boolean          = self.process.isAlive()
-  protected def destroyUnsafe(): Unit           = self.process.destroy()
   protected def destroyForciblyUnsafe: JProcess = self.process.destroyForcibly()
 
   protected def pidUnsafe: Long = self.process.pid
@@ -49,23 +59,26 @@ private[process] trait ProcessPlatformSpecific { self: Process =>
    * Note: This method requires JDK 9+
    */
   def killTree: ZIO[Any, CommandError, Unit] =
-    self.execute { process =>
-      val d = process.descendants().toList().asScala
-      d.foreach { p =>
-        destroyHandle(p)
-        ()
-      }
-
-      destroyUnsafe()
-      waitForUnsafe
-
-      d.foreach { p =>
-        if (isAliveHandle(p)) {
-          onExitHandle(p).get // `ProcessHandle` doesn't have waitFor
-          ()
-        }
-      }
-    }
+    for {
+      descendants <- ZIO.succeed(process.descendants().toList.asScala)
+      _           <- self.execute { _ =>
+                       descendants.foreach { p =>
+                         destroyHandle(p)
+                         ()
+                       }
+
+                       destroyUnsafe()
+                     }
+      _           <- waitFor
+      _           <- self.execute { _ =>
+                       descendants.foreach { p =>
+                         if (isAliveHandle(p)) {
+                           onExitHandle(p).get // `ProcessHandle` doesn't have waitFor
+                           ()
+                         }
+                       }
+                     }
+    } yield ()
 
   /**
    * Kills the entire process tree and will wait until completed. Equivalent to SIGKILL on Unix platforms.
@@ -73,23 +86,26 @@ private[process] trait ProcessPlatformSpecific { self: Process =>
    * Note: This method requires JDK 9+
    */
   def killTreeForcibly: ZIO[Any, CommandError, Unit] =
-    self.execute { process =>
-      val d = process.descendants().toList().asScala
-      d.foreach { p =>
-        destroyForciblyHandle(p)
-        ()
-      }
-
-      destroyForciblyUnsafe
-      waitForUnsafe
-
-      d.foreach { p =>
-        if (isAliveHandle(p)) {
-          onExitHandle(p).get // `ProcessHandle` doesn't have waitFor
-          ()
-        }
-      }
-    }
+    for {
+      descendants <- ZIO.succeed(process.descendants().toList.asScala)
+      _           <- self.execute { _ =>
+                       descendants.foreach { p =>
+                         destroyForciblyHandle(p)
+                         ()
+                       }
+
+                       destroyForciblyUnsafe
+                     }
+      _           <- waitFor
+      _           <- self.execute { _ =>
+                       descendants.foreach { p =>
+                         if (isAliveHandle(p)) {
+                           onExitHandle(p).get // `ProcessHandle` doesn't have waitFor
+                           ()
+                         }
+                       }
+                     }
+    } yield ()
 }
 
 private[process] object ProcessPlatformSpecific {
diff --git a/zio-process/jvm/src/test/bash/both-streams-test.sh b/zio-process/jvm/src/test/bash/both-streams-test.sh
deleted file mode 100755
index 8d264927..00000000
--- a/zio-process/jvm/src/test/bash/both-streams-test.sh
+++ /dev/null
@@ -1,9 +0,0 @@
-#!/bin/bash
-
-echoerr() { echo "$@" 1>&2; }
-
-echo "stdout1"
-echoerr "stderr1"
-
-echo "stdout2"
-echoerr "stderr2"
\ No newline at end of file
diff --git a/zio-process/jvm/src/test/bash/echo-repeat.sh b/zio-process/jvm/src/test/bash/echo-repeat.sh
deleted file mode 100755
index 19d9a657..00000000
--- a/zio-process/jvm/src/test/bash/echo-repeat.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/bash
-
-for i in {1..60}; do echo "iteration: $i"; sleep 1; done
\ No newline at end of file
diff --git a/zio-process/jvm/src/test/bash/kill-test/sample-child.sh b/zio-process/jvm/src/test/bash/kill-test/sample-child.sh
deleted file mode 100755
index 4670b77b..00000000
--- a/zio-process/jvm/src/test/bash/kill-test/sample-child.sh
+++ /dev/null
@@ -1,5 +0,0 @@
-#!/bin/bash
-echo $$
-sleep 30
-echo -n "end: "
-echo $$
diff --git a/zio-process/jvm/src/test/bash/kill-test/sample-parent.sh b/zio-process/jvm/src/test/bash/kill-test/sample-parent.sh
deleted file mode 100755
index 6b21bc13..00000000
--- a/zio-process/jvm/src/test/bash/kill-test/sample-parent.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-echo $$
-./sample-child.sh &
-./sample-child.sh &
-sleep 30
-echo -n "end: "
-echo $$
\ No newline at end of file
diff --git a/zio-process/jvm/src/test/bash/no-permissions.sh b/zio-process/jvm/src/test/bash/no-permissions.sh
deleted file mode 100644
index b2d6f2c3..00000000
--- a/zio-process/jvm/src/test/bash/no-permissions.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/bin/bash
-
-echo "this should not run because it doesn't have execute permissions"
diff --git a/zio-process/jvm/src/test/bash/stdin-echo.sh b/zio-process/jvm/src/test/bash/stdin-echo.sh
deleted file mode 100755
index 0de47dae..00000000
--- a/zio-process/jvm/src/test/bash/stdin-echo.sh
+++ /dev/null
@@ -1,6 +0,0 @@
-#!/bin/bash
-
-while read line
-do
-  echo "$line"
-done
\ No newline at end of file
diff --git a/zio-process/jvm/src/test/scala/zio/process/CommandPlatformSpecificSpec.scala b/zio-process/jvm/src/test/scala/zio/process/CommandPlatformSpecificSpec.scala
index e71ca6c8..fcb25f21 100644
--- a/zio-process/jvm/src/test/scala/zio/process/CommandPlatformSpecificSpec.scala
+++ b/zio-process/jvm/src/test/scala/zio/process/CommandPlatformSpecificSpec.scala
@@ -13,7 +13,8 @@ object CommandPlatformSpecificSpec extends ZIOProcessBaseSpec {
   def spec = suite("CommandSpec")(
     test("killTree also kills child processes") {
       for {
-        process  <- Command("./sample-parent.sh").workingDirectory(new File("src/test/bash/kill-test")).run
+        process  <-
+          Command("./sample-parent.sh").workingDirectory(fileOf("zio-process/shared/src/test/bash/kill-test")).run
         pids     <- process.stdout.stream
                       .via(ZPipeline.utf8Decode)
                       .via(ZPipeline.splitLines)
@@ -28,7 +29,8 @@ object CommandPlatformSpecificSpec extends ZIOProcessBaseSpec {
     } @@ TestAspect.nonFlaky(25),
     test("killTreeForcibly also kills child processes") {
       for {
-        process  <- Command("./sample-parent.sh").workingDirectory(new File("src/test/bash/kill-test")).run
+        process  <-
+          Command("./sample-parent.sh").workingDirectory(fileOf("zio-process/shared/src/test/bash/kill-test")).run
         pids     <- process.stdout.stream
                       .via(ZPipeline.utf8Decode)
                       .via(ZPipeline.splitLines)
@@ -43,7 +45,8 @@ object CommandPlatformSpecificSpec extends ZIOProcessBaseSpec {
     } @@ TestAspect.nonFlaky(25),
     test("kill only kills parent process") {
       for {
-        process  <- Command("./sample-parent.sh").workingDirectory(new File("src/test/bash/kill-test")).run
+        process  <-
+          Command("./sample-parent.sh").workingDirectory(fileOf("zio-process/shared/src/test/bash/kill-test")).run
         pids     <- process.stdout.stream
                       .via(ZPipeline.utf8Decode)
                       .via(ZPipeline.splitLines)
diff --git a/zio-process/jvm/src/test/scala/zio/process/SpecProperties.scala b/zio-process/jvm/src/test/scala/zio/process/SpecProperties.scala
deleted file mode 100644
index 60b9748a..00000000
--- a/zio-process/jvm/src/test/scala/zio/process/SpecProperties.scala
+++ /dev/null
@@ -1,8 +0,0 @@
-package zio.process
-
-trait SpecProperties {
-  val dir = ""
-
-  import FilePlatformSpecific._
-  def mkFile(file: String): File = new File(file)
-}
diff --git a/zio-process/native/src/main/scala/zio/process/CommandPlatformSpecific.scala b/zio-process/native/src/main/scala/zio/process/CommandPlatformSpecific.scala
index 8df1134e..129a8963 100644
--- a/zio-process/native/src/main/scala/zio/process/CommandPlatformSpecific.scala
+++ b/zio-process/native/src/main/scala/zio/process/CommandPlatformSpecific.scala
@@ -16,8 +16,7 @@
 package zio.process
 
 import scala.annotation.nowarn
-import zio.NonEmptyChunk
-import zio.{ Chunk, ZIO }
+import zio._
 import FilePlatformSpecific._
 import java.lang.ProcessBuilder.Redirect
 import scala.jdk.CollectionConverters._
diff --git a/zio-process/native/src/main/scala/zio/process/Constructors.scala b/zio-process/native/src/main/scala/zio/process/Constructors.scala
index dc3626e6..01e09fe2 100644
--- a/zio-process/native/src/main/scala/zio/process/Constructors.scala
+++ b/zio-process/native/src/main/scala/zio/process/Constructors.scala
@@ -20,10 +20,13 @@ import zio.stream.ZStream
 
 import java.io.OutputStream
 import zio.Trace
+
 import java.io.IOException
 import zio.ZIO
 import zio.Chunk
 import zio.Scope
+import zio.process.ProcessPlatformSpecific.JProcess
+
 import java.io.InputStream
 
 private[process] object Constructors {
@@ -52,21 +55,35 @@ private[process] object Constructors {
             val bytes = byteChunk.toArray
             out.write(bytes)
             bytesWritten + bytes.length
-          }.refineOrDie { case e: IOException =>
-            e
-          }
+          }.refineToOrDie[IOException]
         }
       }
     }
 
   def zsink(outputStream: OutputStream): ZSink[Any, IOException, Byte, Byte, Long] = fromOutputStream(outputStream)
 
-  /**
-   * Creates a stream from a `java.io.InputStream`
-   */
-  def fromInputStream(
+  def fromProcessInputStream(process: JProcess)(
     is: => InputStream,
     chunkSize: => Int = ZStream.DefaultChunkSize
-  )(implicit trace: Trace): ZStream[Any, IOException, Byte] = ZStream.fromInputStream(is, chunkSize)
+  )(implicit trace: Trace): ZStream[Any, IOException, Byte] =
+    ZStream.succeed((is, chunkSize)).flatMap { case (is, chunkSize) =>
+      ZStream.repeatZIOChunkOption {
+        for {
+          bufArray  <- ZIO.succeed(Array.ofDim[Byte](chunkSize))
+          bytesRead <- ZIO
+                         .attemptBlockingCancelable(is.read(bufArray))(ZIO.attemptBlocking(process.destroy()).ignore)
+                         .refineToOrDie[IOException]
+                         .asSomeError
+          bytes     <- if (bytesRead < 0)
+                         ZIO.fail(None)
+                       else if (bytesRead == 0)
+                         ZIO.succeed(Chunk.empty)
+                       else if (bytesRead < chunkSize)
+                         ZIO.succeed(Chunk.fromArray(bufArray).take(bytesRead))
+                       else
+                         ZIO.succeed(Chunk.fromArray(bufArray))
+        } yield bytes
+      }
+    }
 
 }
diff --git a/zio-process/native/src/main/scala/zio/process/FilePlatformSpecific.scala b/zio-process/native/src/main/scala/zio/process/FilePlatformSpecific.scala
index 0497cedb..e6c1968f 100644
--- a/zio-process/native/src/main/scala/zio/process/FilePlatformSpecific.scala
+++ b/zio-process/native/src/main/scala/zio/process/FilePlatformSpecific.scala
@@ -1,8 +1,9 @@
 package zio.process
 
-object FilePlatformSpecific {
+private[process] object FilePlatformSpecific {
   type File = java.io.File
 
-  def exists(file: File) = file.exists()
+  def fileOf(file: String): File = new File(file)
 
+  def exists(file: File): Boolean = file.exists()
 }
diff --git a/zio-process/native/src/main/scala/zio/process/ProcessInput.scala b/zio-process/native/src/main/scala/zio/process/ProcessInput.scala
index e04f69e0..52ac42cf 100644
--- a/zio-process/native/src/main/scala/zio/process/ProcessInput.scala
+++ b/zio-process/native/src/main/scala/zio/process/ProcessInput.scala
@@ -16,7 +16,7 @@
 package zio.process
 
 import zio.stream.ZStream
-import zio.{ Chunk, Queue }
+import zio._
 
 import java.io.ByteArrayInputStream
 import java.nio.charset.{ Charset, StandardCharsets }
diff --git a/zio-process/native/src/main/scala/zio/process/ProcessPlatformSpecific.scala b/zio-process/native/src/main/scala/zio/process/ProcessPlatformSpecific.scala
index 04edb62c..93eaeaa9 100644
--- a/zio-process/native/src/main/scala/zio/process/ProcessPlatformSpecific.scala
+++ b/zio-process/native/src/main/scala/zio/process/ProcessPlatformSpecific.scala
@@ -17,7 +17,7 @@ package zio.process
 
 import java.io.InputStream
 import java.io.OutputStream
-import zio.ZIO
+import zio._
 import java.io.PushbackInputStream
 import scala.annotation.nowarn
 
@@ -25,6 +25,16 @@ private[process] trait ProcessPlatformSpecific { self: Process =>
 
   import ProcessPlatformSpecific._
 
+  protected def waitFor: IO[CommandError, ExitCode] =
+    ZIO
+      .attemptBlockingCancelable(waitForUnsafe)(
+        ZIO.attemptBlocking(self.destroyUnsafe()).ignore
+      )
+      .map(x => ExitCode(x))
+      .refineOrDie { case CommandThrowable.IOError(e) =>
+        e
+      }
+
   protected def waitForUnsafe: Int = self.process.waitFor()
 
   protected def isAliveUnsafe: Boolean          = self.process.isAlive()
diff --git a/zio-process/native/src/test/scala/zio/process/SpecProperties.scala b/zio-process/native/src/test/scala/zio/process/SpecProperties.scala
deleted file mode 100644
index 90674eec..00000000
--- a/zio-process/native/src/test/scala/zio/process/SpecProperties.scala
+++ /dev/null
@@ -1,8 +0,0 @@
-package zio.process
-
-trait SpecProperties {
-  val dir = "zio-process/shared/"
-
-  import FilePlatformSpecific._
-  def mkFile(file: String): File = new File(file)
-}
diff --git a/zio-process/shared/src/main/scala/zio/process/Command.scala b/zio-process/shared/src/main/scala/zio/process/Command.scala
index b915cdd9..a514ec74 100644
--- a/zio-process/shared/src/main/scala/zio/process/Command.scala
+++ b/zio-process/shared/src/main/scala/zio/process/Command.scala
@@ -110,7 +110,6 @@ sealed trait Command extends CommandPlatformSpecific {
                      }
           process <- build(c, piping).mapError(CommandThrowable.classify)
           _       <- connectStdin(process, c.stdin)
-
         } yield process
 
       case c: Command.Piped =>
diff --git a/zio-process/shared/src/main/scala/zio/process/Process.scala b/zio-process/shared/src/main/scala/zio/process/Process.scala
index 8a385f74..c73372fa 100644
--- a/zio-process/shared/src/main/scala/zio/process/Process.scala
+++ b/zio-process/shared/src/main/scala/zio/process/Process.scala
@@ -15,8 +15,7 @@
  */
 package zio.process
 
-import zio.ZIO.{ attemptBlockingCancelable, attemptBlockingInterrupt }
-import zio.{ ExitCode, UIO, ZIO }
+import zio._
 
 import java.io.InputStream
 import ProcessPlatformSpecific._
@@ -26,12 +25,12 @@ final case class Process(private[process] val process: JProcess) extends Process
   /**
    * Access the standard output stream.
    */
-  val stdout: ProcessStream = ProcessStream(getInputStream, get)
+  val stdout: ProcessStream = ProcessStream(process, getInputStream, get)
 
   /**
    * Access the standard error stream.
    */
-  val stderr: ProcessStream = ProcessStream(getErrorStream, get)
+  val stderr: ProcessStream = ProcessStream(process, getErrorStream, get)
 
   /**
    * Access the standard output as an Java `InputStream`.
@@ -41,16 +40,14 @@ final case class Process(private[process] val process: JProcess) extends Process
   /**
    * Access the underlying Java Process wrapped in a blocking ZIO.
    */
-  def execute[T](f: JProcess => T): ZIO[Any, CommandError, T] =
-    attemptBlockingInterrupt(f(process)).refineOrDie { case CommandThrowable.IOError(e) => e }
+  def execute[T](f: JProcess => T): IO[CommandError, T] =
+    ZIO.attemptBlockingInterrupt(f(process)).refineOrDie { case CommandThrowable.IOError(e) => e }
 
   /**
    * Return the exit code of this process.
    */
-  def exitCode: ZIO[Any, CommandError, ExitCode]              =
-    attemptBlockingCancelable(ExitCode(waitForUnsafe))(ZIO.succeed(destroyUnsafe())).refineOrDie {
-      case CommandThrowable.IOError(e) => e
-    }
+  def exitCode: IO[CommandError, ExitCode]              =
+    waitFor
 
   /**
    * Tests whether the process is still alive (not terminated or completed).
@@ -62,36 +59,32 @@ final case class Process(private[process] val process: JProcess) extends Process
    *
    * This method requires JDK +9.
    */
-  def pid: ZIO[Any, CommandError, Long] = attemptBlockingInterrupt(pidUnsafe).refineOrDie {
+  def pid: IO[CommandError, Long] = ZIO.attemptBlockingInterrupt(pidUnsafe).refineOrDie {
     case CommandThrowable.IOError(e) => e
   }
 
   /**
    * Kills the process and will wait until completed. Equivalent to SIGTERM on Unix platforms.
    */
-  def kill: ZIO[Any, CommandError, Unit]                   =
-    attemptBlockingInterrupt {
-      destroyUnsafe()
-      waitForUnsafe
-      ()
-    }.refineOrDie { case CommandThrowable.IOError(e) => e }
+  def kill: IO[CommandError, Unit]                   =
+    (for {
+      _ <- ZIO.attemptBlockingInterrupt(destroyUnsafe())
+      _ <- waitFor
+    } yield ()).refineOrDie { case CommandThrowable.IOError(e) => e }
 
   /**
    * Kills the process and will wait until completed. Equivalent to SIGKILL on Unix platforms.
    */
-  def killForcibly: ZIO[Any, CommandError, Unit]           =
-    attemptBlockingInterrupt {
-      destroyForciblyUnsafe
-      waitForUnsafe
-      ()
-    }.refineOrDie { case CommandThrowable.IOError(e) => e }
+  def killForcibly: IO[CommandError, Unit]           =
+    (for {
+      _ <- ZIO.attemptBlockingInterrupt(destroyForciblyUnsafe)
+      _ <- waitFor
+    } yield ()).refineOrDie { case CommandThrowable.IOError(e) => e }
 
   /**
    * Return the exit code of this process if it is zero. If non-zero, it will fail with `CommandError.NonZeroErrorCode`.
    */
-  def successfulExitCode: ZIO[Any, CommandError, ExitCode] =
-    attemptBlockingCancelable(ExitCode(waitForUnsafe))(ZIO.succeed(destroyUnsafe())).refineOrDie {
-      case CommandThrowable.IOError(e) => e: CommandError
-    }.filterOrElseWith(_ == ExitCode.success)(exitCode => ZIO.fail(CommandError.NonZeroErrorCode(exitCode)))
+  def successfulExitCode: IO[CommandError, ExitCode] =
+    waitFor.filterOrElseWith(_ == ExitCode.success)(exitCode => ZIO.fail(CommandError.NonZeroErrorCode(exitCode)))
 
 }
diff --git a/zio-process/shared/src/main/scala/zio/process/ProcessStream.scala b/zio-process/shared/src/main/scala/zio/process/ProcessStream.scala
index 0edc7095..f62798df 100644
--- a/zio-process/shared/src/main/scala/zio/process/ProcessStream.scala
+++ b/zio-process/shared/src/main/scala/zio/process/ProcessStream.scala
@@ -16,14 +16,16 @@
 package zio.process
 
 import zio.ZIO.attemptBlockingCancelable
+import zio.process.ProcessPlatformSpecific.JProcess
 import zio.stream.{ ZPipeline, ZStream }
-import zio.{ Chunk, ZIO }
+import zio._
 
 import java.io._
 import java.nio.charset.{ Charset, StandardCharsets }
 import scala.collection.mutable.ArrayBuffer
 
 final case class ProcessStream(
+  private[process] val process: JProcess,
   private[process] val inputStream: InputStream,
   private[process] val outputStream: Option[OutputStream] = None
 ) {
@@ -79,7 +81,7 @@ final case class ProcessStream(
    */
   def stream: ZStream[Any, CommandError, Byte] =
     Constructors
-      .fromInputStream(inputStream)
+      .fromProcessInputStream(process)(inputStream)
       .ensuring(ZIO.succeed(inputStream.close()))
       .mapError(CommandError.IOError.apply)
 
diff --git a/zio-process/shared/src/test/bash/echo-repeat-short.sh b/zio-process/shared/src/test/bash/echo-repeat-short.sh
new file mode 100755
index 00000000..cf848441
--- /dev/null
+++ b/zio-process/shared/src/test/bash/echo-repeat-short.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+for i in {1..3}; do echo "iteration: $i"; sleep 1; done
\ No newline at end of file
diff --git a/zio-process/shared/src/test/bash/kill-test/sample-child.sh b/zio-process/shared/src/test/bash/kill-test/sample-child.sh
old mode 100644
new mode 100755
diff --git a/zio-process/shared/src/test/bash/kill-test/sample-parent.sh b/zio-process/shared/src/test/bash/kill-test/sample-parent.sh
old mode 100644
new mode 100755
diff --git a/zio-process/shared/src/test/bash/stdin-echo.sh b/zio-process/shared/src/test/bash/stdin-echo.sh
old mode 100644
new mode 100755
diff --git a/zio-process/shared/src/test/scala/zio/process/CommandSpec.scala b/zio-process/shared/src/test/scala/zio/process/CommandSpec.scala
index 779067ce..20dce46d 100644
--- a/zio-process/shared/src/test/scala/zio/process/CommandSpec.scala
+++ b/zio-process/shared/src/test/scala/zio/process/CommandSpec.scala
@@ -3,12 +3,13 @@ package zio.process
 import zio.stream.ZPipeline
 import zio.test.Assertion._
 import zio.test._
-import zio.{ durationInt, Chunk, ExitCode, Queue, System, ZIO }
+import zio._
+import zio.process.FilePlatformSpecific.fileOf
 
 import java.nio.charset.StandardCharsets
 
 // TODO: Add aspects for different OSes? scala.util.Properties.isWin, etc. Also try to make this as OS agnostic as possible in the first place
-object CommandSpec extends ZIOProcessBaseSpec with SpecProperties {
+object CommandSpec extends ZIOProcessBaseSpec {
 
   def spec = suite("CommandSpec")(
     test("convert stdout to string") {
@@ -45,14 +46,15 @@ object CommandSpec extends ZIOProcessBaseSpec with SpecProperties {
 
       assertZIO(zio)(equalTo("a b c"))
     } @@ TestAspect.jvmOnly,
-    test("accept string stdin") { //
+    test("accept string stdin") {
       val zio = Command("cat").stdin(ProcessInput.fromUTF8String("piped in")).string
 
       assertZIO(zio)(equalTo("piped in"))
     },
     test("accept file stdin") {
       for {
-        lines <- Command("cat").stdin(ProcessInput.fromFile(mkFile(s"${dir}src/test/bash/echo-repeat.sh"))).lines
+        lines <-
+          Command("cat").stdin(ProcessInput.fromFile(fileOf(s"zio-process/shared/src/test/bash/echo-repeat.sh"))).lines
       } yield assertTrue(lines.head == "#!/bin/bash")
     },
     test("support different encodings") {
@@ -64,12 +66,12 @@ object CommandSpec extends ZIOProcessBaseSpec with SpecProperties {
       assertZIO(zio)(equalTo("piped in"))
     },
     test("set workingDirectory") {
-      val zio = Command("ls").workingDirectory(mkFile(s"${dir}src/test/bash")).lines
+      val zio = Command("ls").workingDirectory(fileOf(s"zio-process/shared/src/test/bash")).lines
 
       assertZIO(zio)(contains("no-permissions.sh"))
     },
     test("be able to fallback to a different program using typed error channel") {
-      val zio = Command("echo", "-n", "wrong").workingDirectory(mkFile("no-folder")).string.catchSome {
+      val zio = Command("echo", "-n", "wrong").workingDirectory(fileOf("no-folder")).string.catchSome {
         case CommandError.WorkingDirectoryMissing(_) =>
           Command("echo", "-n", "test").string
       }
@@ -85,25 +87,23 @@ object CommandSpec extends ZIOProcessBaseSpec with SpecProperties {
 
       assertZIO(zio.exit)(isInterrupted)
     },
-    test("interrupt a process due to timeout") {
-      val zio = for {
-        fiber       <- Command("sleep", "20").exitCode.timeout(5.seconds).fork
-        adjustFiber <- TestClock.adjust(5.seconds).fork
-        _           <- ZIO.sleep(5.seconds)
-        _           <- adjustFiber.join
-        result      <- fiber.join
-      } yield result
-
-      assertZIO(zio)(isNone)
-    } @@ TestAspect.ignore, // TODO: Until https://github.com/zio/zio/issues/3840 is fixed or there is a workaround
     test("capture stdout and stderr separately") {
       val zio = for {
-        process <- Command(s"${dir}src/test/bash/both-streams-test.sh").run
+        process <- Command(s"zio-process/shared/src/test/bash/both-streams-test.sh").run
         stdout  <- process.stdout.string
         stderr  <- process.stderr.string
       } yield (stdout, stderr)
 
       assertZIO(zio)(equalTo(("stdout1\nstdout2\n", "stderr1\nstderr2\n")))
+    } @@ TestAspect.withLiveClock,
+    test("streaming entire result from stdout should wait for completion") {
+      val zio = for {
+        process <- Command(s"zio-process/shared/src/test/bash/echo-repeat-short.sh").run
+        _       <- ZIO.sleep(5.seconds) // TODO: This should not be needed. If you remove the sleep it fails.
+        stdout  <- process.stdout.string
+      } yield stdout
+
+      assertZIO(zio)(equalTo("iteration: 1\niteration: 2\niteration: 3\n"))
     },
     test("return non-zero exit code in success channel") {
       val zio = Command("ls", "--non-existent-flag").exitCode
@@ -116,20 +116,20 @@ object CommandSpec extends ZIOProcessBaseSpec with SpecProperties {
       assertZIO(zio.exit)(fails(isSubtype[CommandError.NonZeroErrorCode](anything)))
     },
     test("permission denied is a typed error") {
-      val zio = Command(s"${dir}src/test/bash/no-permissions.sh").string
+      val zio = Command(s"zio-process/shared/src/test/bash/no-permissions.sh").string
 
       assertZIO(zio.exit)(fails(isSubtype[CommandError.PermissionDenied](anything)))
     } @@ TestAspect.exceptNative,
     test("redirectErrorStream should merge stderr into stdout") {
       for {
-        process <- Command(s"${dir}src/test/bash/both-streams-test.sh").redirectErrorStream(true).run
+        process <- Command(s"zio-process/shared/src/test/bash/both-streams-test.sh").redirectErrorStream(true).run
         stdout  <- process.stdout.string
         stderr  <- process.stderr.string
       } yield assertTrue(stdout == "stdout1\nstderr1\nstdout2\nstderr2\n", stderr.isEmpty)
     } @@ TestAspect.exceptJS,
     test("be able to kill a process that's running") {
       for {
-        process           <- Command(s"${dir}src/test/bash/echo-repeat.sh").run
+        process           <- Command(s"zio-process/shared/src/test/bash/echo-repeat.sh").run
         isAliveBeforeKill <- process.isAlive
         _                 <- process.kill
         isAliveAfterKill  <- process.isAlive
@@ -137,7 +137,7 @@ object CommandSpec extends ZIOProcessBaseSpec with SpecProperties {
     },
     test("typed error for non-existent working directory") {
       for {
-        exit <- Command("ls").workingDirectory(mkFile("/some/bad/path")).lines.exit
+        exit <- Command("ls").workingDirectory(fileOf("/some/bad/path")).lines.exit
       } yield assert(exit)(fails(isSubtype[CommandError.WorkingDirectoryMissing](anything)))
     },
     test("end of stream also closes underlying process") {
@@ -154,7 +154,7 @@ object CommandSpec extends ZIOProcessBaseSpec with SpecProperties {
       for {
         commandQueue <- Queue.unbounded[Chunk[Byte]]
         process      <- Command("./stdin-echo.sh")
-                          .workingDirectory(mkFile(s"${dir}src/test/bash"))
+                          .workingDirectory(fileOf(s"zio-process/shared/src/test/bash"))
                           .stdin(ProcessInput.fromQueue(commandQueue))
                           .run
         _            <- commandQueue.offer(Chunk.fromArray("line1\nline2\n".getBytes(StandardCharsets.UTF_8)))
@@ -177,13 +177,40 @@ object CommandSpec extends ZIOProcessBaseSpec with SpecProperties {
         _            <- commandQueue.offer(Chunk.fromArray(s"process.exit(0)${sep}".getBytes(StandardCharsets.UTF_8)))
         _            <- fiber.join
       } yield assertCompletes
-    } @@ TestAspect.withLiveClock @@ TestAspect.exceptJS,
+    } @@ TestAspect.exceptJS,
     test("get pid of a running process") {
       for {
         process <- Command("ls").run
         pid     <- process.pid
       } yield assertTrue(pid > 0L)
-    }
-  )
+    },
+    suite("interruption")(
+      test("interrupt a process due to timeout (exitCode)") {
+        for {
+          result <- Command("sleep", "60").exitCode.timeout(3.seconds)
+        } yield assertTrue(result.isEmpty)
+      },
+      test("interrupt a process due to timeout (stream)") {
+        val stream = Command("sleep", "60").stream
+
+        for {
+          result <- stream.runDrain.timeout(3.seconds)
+        } yield assertTrue(result.isEmpty)
+      },
+      test("interrupt a process due to timeout (linesStream)") {
+        val stream = Command("sleep", "60").linesStream
+
+        for {
+          result <- stream.runDrain.timeout(3.seconds)
+        } yield assertTrue(result.isEmpty)
+      },
+      test("interrupt a process due to timeout (stdout stream)") {
+        for {
+          process <- Command("sleep", "60").run
+          result  <- process.stdout.stream.runDrain.timeout(3.seconds)
+        } yield assertTrue(result.isEmpty)
+      }
+    ) @@ TestAspect.exceptNative @@ TestAspect.timeout(30.seconds)
+  ) @@ TestAspect.withLiveClock
 
 }
diff --git a/zio-process/shared/src/test/scala/zio/process/ZIOProcessBaseSpec.scala b/zio-process/shared/src/test/scala/zio/process/ZIOProcessBaseSpec.scala
index d68f69e3..1ef029e7 100644
--- a/zio-process/shared/src/test/scala/zio/process/ZIOProcessBaseSpec.scala
+++ b/zio-process/shared/src/test/scala/zio/process/ZIOProcessBaseSpec.scala
@@ -1,7 +1,7 @@
 package zio.process
 
 import zio.test._
-import zio.{ durationInt, Chunk }
+import zio._
 
 trait ZIOProcessBaseSpec extends ZIOSpecDefault {
   override def aspects = Chunk(TestAspect.timeout(30.seconds))