diff --git a/xpcom/tests/gtest/Helpers.cpp b/xpcom/tests/gtest/Helpers.cpp
index faa019b6686..8a98a5aa096 100644
--- a/xpcom/tests/gtest/Helpers.cpp
+++ b/xpcom/tests/gtest/Helpers.cpp
@@ -94,4 +94,22 @@ ConsumeAndValidateStream(nsIInputStream* aStream,
   ASSERT_TRUE(aExpectedData.Equals(outputData));
 }
 
+NS_IMPL_ISUPPORTS(OutputStreamCallback, nsIOutputStreamCallback);
+
+OutputStreamCallback::OutputStreamCallback()
+  : mCalled(false)
+{
+}
+
+OutputStreamCallback::~OutputStreamCallback()
+{
+}
+
+NS_IMETHODIMP
+OutputStreamCallback::OnOutputStreamReady(nsIAsyncOutputStream* aStream)
+{
+  mCalled = true;
+  return NS_OK;
+}
+
 } // namespace testing
diff --git a/xpcom/tests/gtest/Helpers.h b/xpcom/tests/gtest/Helpers.h
index 0e501ae63e9..1a52370007d 100644
--- a/xpcom/tests/gtest/Helpers.h
+++ b/xpcom/tests/gtest/Helpers.h
@@ -7,6 +7,7 @@
 #ifndef __Helpers_h
 #define __Helpers_h
 
+#include "nsIAsyncOutputStream.h"
 #include "nsString.h"
 #include <stdint.h>
 
@@ -34,6 +35,22 @@ void
 ConsumeAndValidateStream(nsIInputStream* aStream,
                          const nsACString& aExpectedData);
 
+class OutputStreamCallback MOZ_FINAL : public nsIOutputStreamCallback
+{
+public:
+  OutputStreamCallback();
+
+  bool Called() const { return mCalled; }
+
+private:
+  ~OutputStreamCallback();
+
+  bool mCalled;
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOUTPUTSTREAMCALLBACK
+};
+
 } // namespace testing
 
 #endif // __Helpers_h
diff --git a/xpcom/tests/gtest/TestPipes.cpp b/xpcom/tests/gtest/TestPipes.cpp
index 7120a0b5c24..de0942c9055 100644
--- a/xpcom/tests/gtest/TestPipes.cpp
+++ b/xpcom/tests/gtest/TestPipes.cpp
@@ -660,3 +660,127 @@ TEST(Pipes, Clone_DuringWrite_ReadDuringWrite_CloseDuringWrite)
                 2,         // num clones to add after each write
                 3);        // num streams to read after each write
 }
+
+TEST(Pipes, Write_AsyncWait)
+{
+  nsCOMPtr<nsIAsyncInputStream> reader;
+  nsCOMPtr<nsIAsyncOutputStream> writer;
+
+  const uint32_t segmentSize = 1024;
+  const uint32_t numSegments = 1;
+
+  nsresult rv = NS_NewPipe2(getter_AddRefs(reader), getter_AddRefs(writer),
+                            true, true,  // non-blocking - reader, writer
+                            segmentSize, numSegments);
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  nsTArray<char> inputData;
+  testing::CreateData(segmentSize, inputData);
+
+  uint32_t numWritten = 0;
+  rv = writer->Write(inputData.Elements(), inputData.Length(), &numWritten);
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  rv = writer->Write(inputData.Elements(), inputData.Length(), &numWritten);
+  ASSERT_EQ(NS_BASE_STREAM_WOULD_BLOCK, rv);
+
+  nsRefPtr<testing::OutputStreamCallback> cb =
+    new testing::OutputStreamCallback();
+
+  rv = writer->AsyncWait(cb, 0, 0, nullptr);
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  ASSERT_FALSE(cb->Called());
+
+  testing::ConsumeAndValidateStream(reader, inputData);
+
+  ASSERT_TRUE(cb->Called());
+}
+
+TEST(Pipes, Write_AsyncWait_Clone)
+{
+  nsCOMPtr<nsIAsyncInputStream> reader;
+  nsCOMPtr<nsIAsyncOutputStream> writer;
+
+  const uint32_t segmentSize = 1024;
+  const uint32_t numSegments = 1;
+
+  nsresult rv = NS_NewPipe2(getter_AddRefs(reader), getter_AddRefs(writer),
+                            true, true,  // non-blocking - reader, writer
+                            segmentSize, numSegments);
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  nsCOMPtr<nsIInputStream> clone;
+  rv = NS_CloneInputStream(reader, getter_AddRefs(clone));
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  nsTArray<char> inputData;
+  testing::CreateData(segmentSize, inputData);
+
+  uint32_t numWritten = 0;
+  rv = writer->Write(inputData.Elements(), inputData.Length(), &numWritten);
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  rv = writer->Write(inputData.Elements(), inputData.Length(), &numWritten);
+  ASSERT_EQ(NS_BASE_STREAM_WOULD_BLOCK, rv);
+
+  nsRefPtr<testing::OutputStreamCallback> cb =
+    new testing::OutputStreamCallback();
+
+  rv = writer->AsyncWait(cb, 0, 0, nullptr);
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  ASSERT_FALSE(cb->Called());
+
+  testing::ConsumeAndValidateStream(reader, inputData);
+
+  ASSERT_FALSE(cb->Called());
+
+  testing::ConsumeAndValidateStream(clone, inputData);
+
+  ASSERT_TRUE(cb->Called());
+}
+
+TEST(Pipes, Write_AsyncWait_Clone_CloseOriginal)
+{
+  nsCOMPtr<nsIAsyncInputStream> reader;
+  nsCOMPtr<nsIAsyncOutputStream> writer;
+
+  const uint32_t segmentSize = 1024;
+  const uint32_t numSegments = 1;
+
+  nsresult rv = NS_NewPipe2(getter_AddRefs(reader), getter_AddRefs(writer),
+                            true, true,  // non-blocking - reader, writer
+                            segmentSize, numSegments);
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  nsCOMPtr<nsIInputStream> clone;
+  rv = NS_CloneInputStream(reader, getter_AddRefs(clone));
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  nsTArray<char> inputData;
+  testing::CreateData(segmentSize, inputData);
+
+  uint32_t numWritten = 0;
+  rv = writer->Write(inputData.Elements(), inputData.Length(), &numWritten);
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  rv = writer->Write(inputData.Elements(), inputData.Length(), &numWritten);
+  ASSERT_EQ(NS_BASE_STREAM_WOULD_BLOCK, rv);
+
+  nsRefPtr<testing::OutputStreamCallback> cb =
+    new testing::OutputStreamCallback();
+
+  rv = writer->AsyncWait(cb, 0, 0, nullptr);
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  ASSERT_FALSE(cb->Called());
+
+  testing::ConsumeAndValidateStream(clone, inputData);
+
+  ASSERT_FALSE(cb->Called());
+
+  reader->Close();
+
+  ASSERT_TRUE(cb->Called());
+}