Add unit tests for audio channel send frame transformer delegate.

Bug: webrtc:11380
Change-Id: I58a3983d3f16be8ed6a95ea2b9ce759bc3b3a7b7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/174003
Commit-Queue: Marina Ciocea <marinaciocea@webrtc.org>
Reviewed-by: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31159}

audio/BUILD.gn

@@ -128,6 +128,7 @@ if (rtc_include_tests) {
       "audio_send_stream_unittest.cc",
       "audio_state_unittest.cc",
       "channel_receive_frame_transformer_delegate_unittest.cc",
+      "channel_send_frame_transformer_delegate_unittest.cc",
       "mock_voe_channel_proxy.h",
       "remix_resample_unittest.cc",
       "test/audio_stats_test.cc",

audio/channel_send_frame_transformer_delegate_unittest.cc

@@ -0,0 +1,128 @@
+/*
+ *  Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "audio/channel_send_frame_transformer_delegate.h"
+
+#include <memory>
+#include <utility>
+
+#include "rtc_base/ref_counted_object.h"
+#include "rtc_base/task_queue_for_test.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
+#include "test/mock_frame_transformer.h"
+#include "test/mock_transformable_frame.h"
+
+namespace webrtc {
+namespace {
+
+using ::testing::NiceMock;
+using ::testing::SaveArg;
+
+class MockChannelSend {
+ public:
+  MockChannelSend() = default;
+  ~MockChannelSend() = default;
+
+  MOCK_METHOD(int32_t,
+              SendFrame,
+              (AudioFrameType frameType,
+               uint8_t payloadType,
+               uint32_t rtp_timestamp,
+               rtc::ArrayView<const uint8_t> payload,
+               int64_t absolute_capture_timestamp_ms));
+
+  ChannelSendFrameTransformerDelegate::SendFrameCallback callback() {
+    return [this](AudioFrameType frameType, uint8_t payloadType,
+                  uint32_t rtp_timestamp, rtc::ArrayView<const uint8_t> payload,
+                  int64_t absolute_capture_timestamp_ms) {
+      return SendFrame(frameType, payloadType, rtp_timestamp, payload,
+                       absolute_capture_timestamp_ms);
+    };
+  }
+};
+
+// Test that the delegate registers itself with the frame transformer on Init().
+TEST(ChannelSendFrameTransformerDelegateTest,
+     RegisterTransformedFrameCallbackOnInit) {
+  rtc::scoped_refptr<MockFrameTransformer> mock_frame_transformer =
+      new rtc::RefCountedObject<MockFrameTransformer>();
+  rtc::scoped_refptr<ChannelSendFrameTransformerDelegate> delegate =
+      new rtc::RefCountedObject<ChannelSendFrameTransformerDelegate>(
+          ChannelSendFrameTransformerDelegate::SendFrameCallback(),
+          mock_frame_transformer, nullptr);
+  EXPECT_CALL(*mock_frame_transformer, RegisterTransformedFrameCallback);
+  delegate->Init();
+}
+
+// Test that the delegate unregisters itself from the frame transformer on
+// Reset().
+TEST(ChannelSendFrameTransformerDelegateTest,
+     UnregisterTransformedFrameCallbackOnReset) {
+  rtc::scoped_refptr<MockFrameTransformer> mock_frame_transformer =
+      new rtc::RefCountedObject<MockFrameTransformer>();
+  rtc::scoped_refptr<ChannelSendFrameTransformerDelegate> delegate =
+      new rtc::RefCountedObject<ChannelSendFrameTransformerDelegate>(
+          ChannelSendFrameTransformerDelegate::SendFrameCallback(),
+          mock_frame_transformer, nullptr);
+  EXPECT_CALL(*mock_frame_transformer, UnregisterTransformedFrameCallback);
+  delegate->Reset();
+}
+
+// Test that when the delegate receives a transformed frame from the frame
+// transformer, it passes it to the channel using the SendFrameCallback.
+TEST(ChannelSendFrameTransformerDelegateTest,
+     TransformRunsChannelSendCallback) {
+  TaskQueueForTest channel_queue("channel_queue");
+  rtc::scoped_refptr<MockFrameTransformer> mock_frame_transformer =
+      new rtc::RefCountedObject<NiceMock<MockFrameTransformer>>();
+  MockChannelSend mock_channel;
+  rtc::scoped_refptr<ChannelSendFrameTransformerDelegate> delegate =
+      new rtc::RefCountedObject<ChannelSendFrameTransformerDelegate>(
+          mock_channel.callback(), mock_frame_transformer, &channel_queue);
+  rtc::scoped_refptr<TransformedFrameCallback> callback;
+  EXPECT_CALL(*mock_frame_transformer, RegisterTransformedFrameCallback)
+      .WillOnce(SaveArg<0>(&callback));
+  delegate->Init();
+  ASSERT_TRUE(callback);
+
+  const uint8_t data[] = {1, 2, 3, 4};
+  EXPECT_CALL(mock_channel, SendFrame);
+  ON_CALL(*mock_frame_transformer, Transform)
+      .WillByDefault(
+          [&callback](std::unique_ptr<TransformableFrameInterface> frame) {
+            callback->OnTransformedFrame(std::move(frame));
+          });
+  delegate->Transform(AudioFrameType::kEmptyFrame, 0, 0, 0, data, sizeof(data),
+                      0, 0);
+  channel_queue.WaitForPreviouslyPostedTasks();
+}
+
+// Test that if the delegate receives a transformed frame after it has been
+// reset, it does not run the SendFrameCallback, as the channel is destroyed
+// after resetting the delegate.
+TEST(ChannelSendFrameTransformerDelegateTest,
+     OnTransformedDoesNotRunChannelSendCallbackAfterReset) {
+  TaskQueueForTest channel_queue("channel_queue");
+  rtc::scoped_refptr<MockFrameTransformer> mock_frame_transformer =
+      new rtc::RefCountedObject<testing::NiceMock<MockFrameTransformer>>();
+  MockChannelSend mock_channel;
+  rtc::scoped_refptr<ChannelSendFrameTransformerDelegate> delegate =
+      new rtc::RefCountedObject<ChannelSendFrameTransformerDelegate>(
+          mock_channel.callback(), mock_frame_transformer, &channel_queue);
+
+  delegate->Reset();
+  EXPECT_CALL(mock_channel, SendFrame).Times(0);
+  delegate->OnTransformedFrame(std::make_unique<MockTransformableFrame>());
+  channel_queue.WaitForPreviouslyPostedTasks();
+}
+
+}  // namespace
+}  // namespace webrtc