diff --git a/ktor-client/ktor-client-tests/build.gradle.kts b/ktor-client/ktor-client-tests/build.gradle.kts
index 575f41a802..7d882df44f 100644
--- a/ktor-client/ktor-client-tests/build.gradle.kts
+++ b/ktor-client/ktor-client-tests/build.gradle.kts
@@ -41,7 +41,7 @@ kotlin.sourceSets {
         dependencies {
             api(project(":ktor-client:ktor-client-core"))
             api(project(":ktor-client:ktor-client-mock"))
-            api(project(":ktor-client:ktor-client-tests:ktor-client-tests-dispatcher"))
+            api(project(":ktor-test-dispatcher"))
             api(project(":ktor-client:ktor-client-features:ktor-client-json:ktor-client-serialization"))
         }
     }
diff --git a/ktor-client/ktor-client-tests/common/src/io/ktor/client/tests/utils/CommonClientTestUtils.kt b/ktor-client/ktor-client-tests/common/src/io/ktor/client/tests/utils/CommonClientTestUtils.kt
index a57ed70723..449ca2c061 100644
--- a/ktor-client/ktor-client-tests/common/src/io/ktor/client/tests/utils/CommonClientTestUtils.kt
+++ b/ktor-client/ktor-client-tests/common/src/io/ktor/client/tests/utils/CommonClientTestUtils.kt
@@ -6,7 +6,7 @@ package io.ktor.client.tests.utils
 
 import io.ktor.client.*
 import io.ktor.client.engine.*
-import io.ktor.client.tests.utils.dispatcher.*
+import io.ktor.test.dispatcher.*
 import io.ktor.util.*
 import kotlinx.coroutines.*
 import io.ktor.utils.io.core.*
diff --git a/ktor-io/build.gradle b/ktor-io/build.gradle
index 90d450c09c..5606938568 100644
--- a/ktor-io/build.gradle
+++ b/ktor-io/build.gradle
@@ -11,4 +11,7 @@ kotlin {
             }
         }
     }
+    sourceSets.commonTest.dependencies {
+        api project(":ktor-test-dispatcher")
+    }
 }
diff --git a/ktor-io/common/src/io/ktor/utils/io/ByteChannelSequential.kt b/ktor-io/common/src/io/ktor/utils/io/ByteChannelSequential.kt
index 6ca97dac8a..27ae802504 100644
--- a/ktor-io/common/src/io/ktor/utils/io/ByteChannelSequential.kt
+++ b/ktor-io/common/src/io/ktor/utils/io/ByteChannelSequential.kt
@@ -675,7 +675,9 @@ abstract class ByteChannelSequentialBase(
 
     protected suspend fun awaitFreeSpace() {
         afterWrite()
-        return notFull.await { flush() }
+        notFull.await {
+            flush()
+        }
     }
 
     final override suspend fun peekTo(
diff --git a/ktor-io/common/src/io/ktor/utils/io/Coroutines.kt b/ktor-io/common/src/io/ktor/utils/io/Coroutines.kt
index 1ebe7636f8..9cbf632325 100644
--- a/ktor-io/common/src/io/ktor/utils/io/Coroutines.kt
+++ b/ktor-io/common/src/io/ktor/utils/io/Coroutines.kt
@@ -113,7 +113,8 @@ private fun <S : CoroutineScope> CoroutineScope.launchChannel(
     context: CoroutineContext,
     channel: ByteChannel,
     attachJob: Boolean,
-    block: suspend S.() -> Unit): ChannelJob {
+    block: suspend S.() -> Unit
+): ChannelJob {
 
     val job = launch(context) {
         if (attachJob) {
@@ -130,10 +131,14 @@ private fun <S : CoroutineScope> CoroutineScope.launchChannel(
     return ChannelJob(job, channel)
 }
 
-private class ChannelScope(delegate: CoroutineScope,
-                           override val channel: ByteChannel) : ReaderScope, WriterScope, CoroutineScope by delegate
+private class ChannelScope(
+    delegate: CoroutineScope,
+    override val channel: ByteChannel
+) : ReaderScope, WriterScope, CoroutineScope by delegate
 
 private class ChannelJob(
-    delegate: Job,
+    private val delegate: Job,
     override val channel: ByteChannel
-) : ReaderJob, WriterJob, Job by delegate
+) : ReaderJob, WriterJob, Job by delegate {
+    override fun toString(): String = "ChannelJob[$delegate]"
+}
diff --git a/ktor-io/common/test/io/ktor/utils/io/tests/ByteChannelBuildersTest.kt b/ktor-io/common/test/io/ktor/utils/io/tests/ByteChannelBuildersTest.kt
new file mode 100644
index 0000000000..d9d29dcfae
--- /dev/null
+++ b/ktor-io/common/test/io/ktor/utils/io/tests/ByteChannelBuildersTest.kt
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2014-2019 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.utils.io.tests
+
+import io.ktor.utils.io.*
+import kotlinx.coroutines.*
+import kotlin.test.*
+import io.ktor.test.dispatcher.*
+
+class ByteChannelBuildersTest {
+    @Test
+    fun testWriterCancelledByChannel() = testSuspend {
+        val context = Job()
+        val scope = CoroutineScope(context)
+
+        val task = scope.writer {
+            val data = ByteArray(8 * 1024)
+            while (true) {
+                channel.writeFully(data)
+            }
+        }
+
+        context.complete()
+        task.channel.cancel()
+        task.join()
+        assertTrue(task.isCancelled)
+        assertTrue(context.isCompleted)
+    }
+}
diff --git a/ktor-io/js/src/io/ktor/utils/io/ByteChannelJS.kt b/ktor-io/js/src/io/ktor/utils/io/ByteChannelJS.kt
index c069b4d955..8f7f4e958e 100644
--- a/ktor-io/js/src/io/ktor/utils/io/ByteChannelJS.kt
+++ b/ktor-io/js/src/io/ktor/utils/io/ByteChannelJS.kt
@@ -125,4 +125,6 @@ internal class ByteChannelJS(initial: IoBuffer, autoFlush: Boolean) : ByteChanne
             remaining -= rc
         }
     }
+
+    override fun toString(): String = "ByteChannel[$attachedJob, ${hashCode()}]"
 }
diff --git a/ktor-io/js/src/io/ktor/utils/io/ByteReadChannel.kt b/ktor-io/js/src/io/ktor/utils/io/ByteReadChannel.kt
index 288768eadf..04a5f5185a 100644
--- a/ktor-io/js/src/io/ktor/utils/io/ByteReadChannel.kt
+++ b/ktor-io/js/src/io/ktor/utils/io/ByteReadChannel.kt
@@ -1,6 +1,6 @@
 package io.ktor.utils.io
 
-import io.ktor.utils.io.bits.Memory
+import io.ktor.utils.io.bits.*
 import io.ktor.utils.io.core.*
 import org.khronos.webgl.*
 
@@ -57,6 +57,7 @@ actual interface ByteReadChannel {
      * Suspends if not enough bytes available.
      */
     actual suspend fun readFully(dst: ByteArray, offset: Int, length: Int)
+
     actual suspend fun readFully(dst: IoBuffer, n: Int)
 
     suspend fun readFully(dst: ArrayBuffer, offset: Int, length: Int)
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/build.gradle.kts b/ktor-test-dispatcher/build.gradle.kts
similarity index 100%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/build.gradle.kts
rename to ktor-test-dispatcher/build.gradle.kts
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/common/src/TestCommon.kt b/ktor-test-dispatcher/common/src/TestCommon.kt
similarity index 89%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/common/src/TestCommon.kt
rename to ktor-test-dispatcher/common/src/TestCommon.kt
index 49cad8d902..e995de9b27 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/common/src/TestCommon.kt
+++ b/ktor-test-dispatcher/common/src/TestCommon.kt
@@ -2,7 +2,7 @@
  * Copyright 2014-2019 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
  */
 
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/iosArm32/src/TestIosArm32.kt b/ktor-test-dispatcher/iosArm32/src/TestIosArm32.kt
similarity index 92%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/iosArm32/src/TestIosArm32.kt
rename to ktor-test-dispatcher/iosArm32/src/TestIosArm32.kt
index fbcdc0368b..fc8cc3c025 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/iosArm32/src/TestIosArm32.kt
+++ b/ktor-test-dispatcher/iosArm32/src/TestIosArm32.kt
@@ -1,6 +1,6 @@
 @file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
 
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/iosArm64/src/TestIosArm64.kt b/ktor-test-dispatcher/iosArm64/src/TestIosArm64.kt
similarity index 92%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/iosArm64/src/TestIosArm64.kt
rename to ktor-test-dispatcher/iosArm64/src/TestIosArm64.kt
index fbcdc0368b..fc8cc3c025 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/iosArm64/src/TestIosArm64.kt
+++ b/ktor-test-dispatcher/iosArm64/src/TestIosArm64.kt
@@ -1,6 +1,6 @@
 @file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
 
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/iosX64/src/TestIosX64.kt b/ktor-test-dispatcher/iosX64/src/TestIosX64.kt
similarity index 92%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/iosX64/src/TestIosX64.kt
rename to ktor-test-dispatcher/iosX64/src/TestIosX64.kt
index fbcdc0368b..fc8cc3c025 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/iosX64/src/TestIosX64.kt
+++ b/ktor-test-dispatcher/iosX64/src/TestIosX64.kt
@@ -1,6 +1,6 @@
 @file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
 
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/js/src/TestJs.kt b/ktor-test-dispatcher/js/src/TestJs.kt
similarity index 89%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/js/src/TestJs.kt
rename to ktor-test-dispatcher/js/src/TestJs.kt
index 45817cf3c4..51cc8ef9c2 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/js/src/TestJs.kt
+++ b/ktor-test-dispatcher/js/src/TestJs.kt
@@ -2,7 +2,7 @@
  * Copyright 2014-2019 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
  */
 
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/jvm/src/TestJvm.kt b/ktor-test-dispatcher/jvm/src/TestJvm.kt
similarity index 88%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/jvm/src/TestJvm.kt
rename to ktor-test-dispatcher/jvm/src/TestJvm.kt
index 36cd497fe7..430e4600c6 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/jvm/src/TestJvm.kt
+++ b/ktor-test-dispatcher/jvm/src/TestJvm.kt
@@ -2,7 +2,7 @@
  * Copyright 2014-2019 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
  */
 
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/linuxX64/src/TestLinuxX64.kt b/ktor-test-dispatcher/linuxX64/src/TestLinuxX64.kt
similarity index 84%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/linuxX64/src/TestLinuxX64.kt
rename to ktor-test-dispatcher/linuxX64/src/TestLinuxX64.kt
index 535c8d9a85..c5566379f6 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/linuxX64/src/TestLinuxX64.kt
+++ b/ktor-test-dispatcher/linuxX64/src/TestLinuxX64.kt
@@ -1,4 +1,4 @@
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/macosX64/src/TestMacosX64.kt b/ktor-test-dispatcher/macosX64/src/TestMacosX64.kt
similarity index 92%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/macosX64/src/TestMacosX64.kt
rename to ktor-test-dispatcher/macosX64/src/TestMacosX64.kt
index fbcdc0368b..fc8cc3c025 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/macosX64/src/TestMacosX64.kt
+++ b/ktor-test-dispatcher/macosX64/src/TestMacosX64.kt
@@ -1,6 +1,6 @@
 @file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
 
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/mingwX64/src/TestMingwX64.kt b/ktor-test-dispatcher/mingwX64/src/TestMingwX64.kt
similarity index 84%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/mingwX64/src/TestMingwX64.kt
rename to ktor-test-dispatcher/mingwX64/src/TestMingwX64.kt
index 535c8d9a85..c5566379f6 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/mingwX64/src/TestMingwX64.kt
+++ b/ktor-test-dispatcher/mingwX64/src/TestMingwX64.kt
@@ -1,4 +1,4 @@
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/posix/src/.gitkeep b/ktor-test-dispatcher/posix/src/.gitkeep
similarity index 100%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/posix/src/.gitkeep
rename to ktor-test-dispatcher/posix/src/.gitkeep
diff --git a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/posixIde/src/TestIde.kt b/ktor-test-dispatcher/posixIde/src/TestIde.kt
similarity index 88%
rename from ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/posixIde/src/TestIde.kt
rename to ktor-test-dispatcher/posixIde/src/TestIde.kt
index a820d9b3d3..22a2ac3677 100644
--- a/ktor-client/ktor-client-tests/ktor-client-tests-dispatcher/posixIde/src/TestIde.kt
+++ b/ktor-test-dispatcher/posixIde/src/TestIde.kt
@@ -2,7 +2,7 @@
  * Copyright 2014-2019 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
  */
 
-package io.ktor.client.tests.utils.dispatcher
+package io.ktor.test.dispatcher
 
 import kotlinx.coroutines.*
 import kotlin.coroutines.*
diff --git a/settings.gradle b/settings.gradle
index df6aa190d4..7b6a02ec86 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -32,7 +32,6 @@ include ':ktor-server'
 include ':ktor-client'
 include ':ktor-client:ktor-client-core'
 include ':ktor-client:ktor-client-tests'
-include ':ktor-client:ktor-client-tests:ktor-client-tests-dispatcher'
 include ':ktor-client:ktor-client-apache'
 include ':ktor-client:ktor-client-android'
 include ':ktor-client:ktor-client-cio'
@@ -80,3 +79,4 @@ include ':ktor-network'
 include ':ktor-network:ktor-network-tls'
 include ':ktor-network:ktor-network-tls:ktor-network-tls-certificates'
 include ':ktor-bom'
+include ':ktor-test-dispatcher'