Major part of CrasAudioClientUnittest

chromeos/dbus/cras_audio_client_unittest.cc

Index: chromeos/dbus/cras_audio_client_unittest.cc
diff --git a/chromeos/dbus/cras_audio_client_unittest.cc b/chromeos/dbus/cras_audio_client_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a436a864fdb8fc26a728d776aa5ae1ce1444c6be
--- /dev/null
+++ b/chromeos/dbus/cras_audio_client_unittest.cc
@@ -0,0 +1,702 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.

[jennyz, 2016/04/14 00:12:31]

2012 -> 2016
remove (c): This is deprecated style.

http://www.chromium.org/developers/coding-style#TOC-File-headers

[Qiang(Joe) Xu, 2016/04/14 01:25:48]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chromeos/dbus/cras_audio_client.h"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "dbus/message.h"
+#include "dbus/mock_bus.h"
+#include "dbus/mock_object_proxy.h"
+#include "dbus/object_path.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/cros_system_api/dbus/service_constants.h"
+
+using ::testing::_;
+using ::testing::Invoke;
+using ::testing::Return;
+
+namespace chromeos {
+
+namespace {
+
+// Audio nodes for GetNodes unit test.
+const uint64_t kInternalSpeakerId = 10001;
+const uint64_t kInternalMicId = 20001;
+
+const AudioNode kInternalSpeaker(false,
+                                 kInternalSpeakerId,
+                                 kInternalSpeakerId,
+                                 "Fake Speaker",
+                                 "INTERNAL_SPEAKER",
+                                 "Speaker",
+                                 false,
+                                 0);
+
+const AudioNode kInternalMic(true,
+                             kInternalMicId,
+                             kInternalMicId,
+                             "Fake Mic",
+                             "INTERNAL_MIC",
+                             "Internal Mic",
+                             false,
+                             0);
+// A mock ErrorCallback.
+class MockErrorCallback {
+ public:
+  MockErrorCallback() {}
+  ~MockErrorCallback() {}
+  MOCK_METHOD2(Run, void(const std::string& error_name,
+                         const std::string& error_message));
+  CrasAudioClient::ErrorCallback GetCallback() {
+    return base::Bind(&MockErrorCallback::Run, base::Unretained(this));
+  }
+};
+
+// A mock CrasAudioClient Observer.
+class MockObserver : public CrasAudioClient::Observer {
+ public:
+  MockObserver() {}
+  ~MockObserver() override {}
+  MOCK_METHOD1(OutputMuteChanged, void(bool mute_on));
+  MOCK_METHOD1(InputMuteChanged, void(bool mute_on));
+  MOCK_METHOD0(NodesChanged, void());
+  MOCK_METHOD1(ActiveOutputNodeChanged, void(uint64_t node_id));
+  MOCK_METHOD1(ActiveInputNodeChanged, void(uint64_t node_id));
+};
+
+// Expect the reader to be empty.
+void ExpectNoArgument(dbus::MessageReader* reader) {
+  EXPECT_FALSE(reader->HasMoreData());
+}
+
+// Expect the reader to have an int32_t and an array of doubles.
+void ExpectInt32AndArrayOfDoublesArguments(
+    int32_t expected_value,
+    const std::vector<double>& expected_doubles,
+    dbus::MessageReader* reader) {
+  int32_t value;
+  ASSERT_TRUE(reader->PopInt32(&value));
+  EXPECT_EQ(expected_value, value);
+  const double* doubles = nullptr;
+  size_t size = 0;
+  ASSERT_TRUE(reader->PopArrayOfDoubles(&doubles, &size));
+  EXPECT_EQ(expected_doubles.size(), size);
+  for (size_t i = 0; i < size; ++i) {
+    EXPECT_EQ(expected_doubles[i], doubles[i]);
+  }
+  EXPECT_FALSE(reader->HasMoreData());
+}
+
+// Expect the VolumeState result.
+void ExpectVolumeStateResult(const VolumeState* expected_volume_state,
+                             const VolumeState& volume_state,
+                             bool call_status) {
+  EXPECT_EQ(true, call_status);
+  EXPECT_EQ(expected_volume_state->output_volume, volume_state.output_volume);
+  EXPECT_EQ(expected_volume_state->output_system_mute,
+            volume_state.output_system_mute);
+  EXPECT_EQ(expected_volume_state->input_gain, volume_state.input_gain);
+  EXPECT_EQ(expected_volume_state->input_mute, volume_state.input_mute);
+  EXPECT_EQ(expected_volume_state->output_user_mute,
+            volume_state.output_user_mute);
+}
+
+// Expect the AudioNodeList result.
+void ExpectAudioNodeListResult(const AudioNodeList* expected_node_list,
+                               const AudioNodeList& node_list,
+                               bool call_status) {
+  EXPECT_EQ(true, call_status);
+  EXPECT_EQ(expected_node_list->size(), node_list.size());
+  for (size_t i = 0; i < node_list.size(); ++i) {
+    EXPECT_EQ((*expected_node_list)[i].is_input, node_list[i].is_input);
+    EXPECT_EQ((*expected_node_list)[i].id, node_list[i].id);
+    EXPECT_EQ((*expected_node_list)[i].stable_device_id,
+              node_list[i].stable_device_id);
+    EXPECT_EQ((*expected_node_list)[i].device_name, node_list[i].device_name);
+    EXPECT_EQ((*expected_node_list)[i].type, node_list[i].type);
+    EXPECT_EQ((*expected_node_list)[i].name, node_list[i].name);
+    EXPECT_EQ((*expected_node_list)[i].mic_positions,
+              node_list[i].mic_positions);
+    EXPECT_EQ((*expected_node_list)[i].active, node_list[i].active);
+    EXPECT_EQ((*expected_node_list)[i].plugged_time, node_list[i].plugged_time);
+  }
+}
+
+}  // namespace
+
+class CrasAudioClientTest : public testing::Test {
+ public:
+  CrasAudioClientTest() : interface_name_(cras::kCrasControlInterface),
+                          response_(nullptr) {}
+
+  void SetUp() override {
+    // Create a mock bus.
+    dbus::Bus::Options options;
+    options.bus_type = dbus::Bus::SYSTEM;
+    mock_bus_ = new dbus::MockBus(options);
+
+    // Create a mock cras proxy.
+    mock_cras_proxy_ = new dbus::MockObjectProxy(
+        mock_bus_.get(),
+        cras::kCrasServiceName,
+        dbus::ObjectPath(cras::kCrasServicePath));
+
+    // Set an expectation so mock_cras_proxy's CallMethod() will use
+    // OnCallMethod() to return responses.
+    EXPECT_CALL(*mock_cras_proxy_.get(), CallMethod(_, _, _))
+        .WillRepeatedly(Invoke(this, &CrasAudioClientTest::OnCallMethod));
+
+    // Set an expectation so mock_cras_proxy's CallMethodWithErrorCallback()
+    // will use OnCallMethodWithErrorCallback() to return responses.
+    EXPECT_CALL(*mock_cras_proxy_.get(),
+                CallMethodWithErrorCallback(_, _, _, _))
+        .WillRepeatedly(
+            Invoke(this, &CrasAudioClientTest::OnCallMethodWithErrorCallback));
+
+    // Set an expectation so mock_cras_proxy's monitoring OutputMuteChanged
+    // ConnectToSignal will use OnConnectToOutputMuteChanged() to run the
+    // callback.
+    EXPECT_CALL(
+        *mock_cras_proxy_.get(),
+        ConnectToSignal(interface_name_, cras::kOutputMuteChanged, _, _))
+        .WillRepeatedly(
+            Invoke(this, &CrasAudioClientTest::OnConnectToOutputMuteChanged));
+
+    // Set an expectation so mock_cras_proxy's monitoring InputMuteChanged
+    // ConnectToSignal will use OnConnectToInputMuteChanged() to run the
+    // callback.
+    EXPECT_CALL(
+        *mock_cras_proxy_.get(),
+        ConnectToSignal(interface_name_, cras::kInputMuteChanged, _, _))
+        .WillRepeatedly(
+            Invoke(this, &CrasAudioClientTest::OnConnectToInputMuteChanged));
+
+    // Set an expectation so mock_cras_proxy's monitoring NodesChanged
+    // ConnectToSignal will use OnConnectToNodesChanged() to run the callback.
+    EXPECT_CALL(
+        *mock_cras_proxy_.get(),
+        ConnectToSignal(interface_name_, cras::kNodesChanged, _, _))
+        .WillRepeatedly(
+            Invoke(this, &CrasAudioClientTest::OnConnectToNodesChanged));
+
+    // Set an expectation so mock_cras_proxy's monitoring
+    // ActiveOutputNodeChanged ConnectToSignal will use
+    // OnConnectToActiveOutputNodeChanged() to run the callback.
+    EXPECT_CALL(
+        *mock_cras_proxy_.get(),
+        ConnectToSignal(interface_name_, cras::kActiveOutputNodeChanged, _, _))
+        .WillRepeatedly(
+            Invoke(this,
+                   &CrasAudioClientTest::OnConnectToActiveOutputNodeChanged));
+
+    // Set an expectation so mock_cras_proxy's monitoring
+    // ActiveInputNodeChanged ConnectToSignal will use
+    // OnConnectToActiveInputNodeChanged() to run the callback.
+    EXPECT_CALL(
+        *mock_cras_proxy_.get(),
+        ConnectToSignal(interface_name_, cras::kActiveInputNodeChanged, _, _))
+        .WillRepeatedly(
+            Invoke(this,
+                   &CrasAudioClientTest::OnConnectToActiveInputNodeChanged));
+
+    // Set an expectation so mock_bus's GetObjectProxy() for the given
+    // service name and the object path will return mock_cras_proxy_.
+    EXPECT_CALL(*mock_bus_.get(),
+                GetObjectProxy(cras::kCrasServiceName,
+                               dbus::ObjectPath(cras::kCrasServicePath)))
+        .WillOnce(Return(mock_cras_proxy_.get()));
+
+    // ShutdownAndBlock() will be called in TearDown().
+    EXPECT_CALL(*mock_bus_.get(), ShutdownAndBlock()).WillOnce(Return());
+
+    // Create a client with the mock bus.
+    client_.reset(CrasAudioClient::Create());
+    client_->Init(mock_bus_.get());
+    // Run the message loop to run the signal connection result callback.
+    message_loop_.RunUntilIdle();
+  }
+
+  void TearDown() override { mock_bus_->ShutdownAndBlock(); }
+
+ protected:
+  // A callback to intercept and check the method call arguments.
+  typedef base::Callback<void(
+      dbus::MessageReader* reader)> ArgumentCheckCallback;
+
+  // Sets expectations for called method name and arguments, and sets response.
+  void PrepareForMethodCall(const std::string& method_name,
+                            const ArgumentCheckCallback& argument_checker,
+                            dbus::Response* response) {
+    expected_method_name_ = method_name;
+    argument_checker_ = argument_checker;
+    response_ = response;
+  }
+
+  // Send output mute changed signal to the tested client.
+  void SendOutputMuteChangedSignal(dbus::Signal* signal) {
+    ASSERT_FALSE(output_mute_changed_handler_.is_null());
+    output_mute_changed_handler_.Run(signal);
+  }
+
+  // Send input mute changed signal to the tested client.
+  void SendInputMuteChangedSignal(dbus::Signal* signal) {
+    ASSERT_FALSE(input_mute_changed_handler_.is_null());
+    input_mute_changed_handler_.Run(signal);
+  }
+
+  // Send nodes changed signal to the tested client.
+  void SendNodesChangedSignal(dbus::Signal* signal) {
+    ASSERT_FALSE(nodes_changed_handler_.is_null());
+    nodes_changed_handler_.Run(signal);
+  }
+
+  // Send active output node changed signal to the tested client.
+  void SendActiveOutputNodeChangedSignal(dbus::Signal* signal) {
+    ASSERT_FALSE(active_output_node_changed_handler_.is_null());
+    active_output_node_changed_handler_.Run(signal);
+  }
+
+  // Send active input node changed signal to the tested client.
+  void SendActiveInputNodeChangedSignal(dbus::Signal* signal) {
+    ASSERT_FALSE(active_input_node_changed_handler_.is_null());
+    active_input_node_changed_handler_.Run(signal);
+  }
+
+  // The interface name.
+  const std::string interface_name_;
+  // The client to be tested.
+  std::unique_ptr<CrasAudioClient> client_;
+  // A message loop to emulate asynchronous behavior.
+  base::MessageLoop message_loop_;
+  // The mock bus.
+  scoped_refptr<dbus::MockBus> mock_bus_;
+  // The mock object proxy.
+  scoped_refptr<dbus::MockObjectProxy> mock_cras_proxy_;
+  // The OutputMuteChanged signal handler given by the tested client.
+  dbus::ObjectProxy::SignalCallback output_mute_changed_handler_;
+  // The InputMuteChanged signal handler given by the tested client.
+  dbus::ObjectProxy::SignalCallback input_mute_changed_handler_;
+  // The NodesChanged signal handler given by the tested client.
+  dbus::ObjectProxy::SignalCallback nodes_changed_handler_;
+  // The ActiveOutputNodeChanged signal handler given by the tested client.
+  dbus::ObjectProxy::SignalCallback active_output_node_changed_handler_;
+  // The ActiveInputNodeChanged signal handler given by the tested client.
+  dbus::ObjectProxy::SignalCallback active_input_node_changed_handler_;
+  // The name of the method which is expected to be called.
+  std::string expected_method_name_;
+  // The response which the mock cras proxy returns.
+  dbus::Response* response_;
+  // A callback to intercept and check the method call arguments.
+  ArgumentCheckCallback argument_checker_;
+
+ private:
+  // Checks the requested interface name and signal name.
+  // Used to implement the mock cras proxy.
+  void OnConnectToOutputMuteChanged(
+      const std::string& interface_name,
+      const std::string& signal_name,
+      const dbus::ObjectProxy::SignalCallback& signal_callback,
+      const dbus::ObjectProxy::OnConnectedCallback& on_connected_callback) {
+    output_mute_changed_handler_ = signal_callback;
+    const bool success = true;
+    message_loop_.task_runner()->PostTask(FROM_HERE,
+                                          base::Bind(on_connected_callback,
+                                                     interface_name,
+                                                     signal_name,
+                                                     success));
+  }
+
+  // Checks the requested interface name and signal name.
+  // Used to implement the mock cras proxy.
+  void OnConnectToInputMuteChanged(
+      const std::string& interface_name,
+      const std::string& signal_name,
+      const dbus::ObjectProxy::SignalCallback& signal_callback,
+      const dbus::ObjectProxy::OnConnectedCallback& on_connected_callback) {
+    input_mute_changed_handler_ = signal_callback;
+    const bool success = true;
+    message_loop_.task_runner()->PostTask(FROM_HERE,
+                                          base::Bind(on_connected_callback,
+                                                     interface_name,
+                                                     signal_name,
+                                                     success));
+  }
+
+  // Checks the requested interface name and signal name.
+  // Used to implement the mock cras proxy.
+  void OnConnectToNodesChanged(
+      const std::string& interface_name,
+      const std::string& signal_name,
+      const dbus::ObjectProxy::SignalCallback& signal_callback,
+      const dbus::ObjectProxy::OnConnectedCallback& on_connected_callback) {
+    nodes_changed_handler_ = signal_callback;
+    const bool success = true;
+    message_loop_.task_runner()->PostTask(FROM_HERE,
+                                          base::Bind(on_connected_callback,
+                                                     interface_name,
+                                                     signal_name,
+                                                     success));
+  }
+
+  // Checks the requested interface name and signal name.
+  // Used to implement the mock cras proxy.
+  void OnConnectToActiveOutputNodeChanged(
+      const std::string& interface_name,
+      const std::string& signal_name,
+      const dbus::ObjectProxy::SignalCallback& signal_callback,
+      const dbus::ObjectProxy::OnConnectedCallback& on_connected_callback) {
+    active_output_node_changed_handler_ = signal_callback;
+    const bool success = true;
+    message_loop_.task_runner()->PostTask(FROM_HERE,
+                                          base::Bind(on_connected_callback,
+                                                     interface_name,
+                                                     signal_name,
+                                                     success));
+  }
+
+  // Checks the requested interface name and signal name.
+  // Used to implement the mock cras proxy.
+  void OnConnectToActiveInputNodeChanged(
+      const std::string& interface_name,
+      const std::string& signal_name,
+      const dbus::ObjectProxy::SignalCallback& signal_callback,
+      const dbus::ObjectProxy::OnConnectedCallback& on_connected_callback) {
+    active_input_node_changed_handler_ = signal_callback;
+    const bool success = true;
+    message_loop_.task_runner()->PostTask(FROM_HERE,
+                                          base::Bind(on_connected_callback,
+                                                     interface_name,
+                                                     signal_name,
+                                                     success));
+  }
+
+  // Checks the content of the method call and returns the response.
+  // Used to implement the mock cras proxy.
+  void OnCallMethod(dbus::MethodCall* method_call,
+                    int timeout_ms,
+                    const dbus::ObjectProxy::ResponseCallback& response) {
+    EXPECT_EQ(interface_name_, method_call->GetInterface());
+    EXPECT_EQ(expected_method_name_, method_call->GetMember());
+    dbus::MessageReader reader(method_call);
+    argument_checker_.Run(&reader);
+    message_loop_.task_runner()->PostTask(
+        FROM_HERE, base::Bind(response, response_));
+  }
+
+  // Checks the content of the method call and returns the response.
+  // Used to implement the mock cras proxy.
+  void OnCallMethodWithErrorCallback(
+      dbus::MethodCall* method_call,
+      int timeout_ms,
+      const dbus::ObjectProxy::ResponseCallback& response_callback,
+      const dbus::ObjectProxy::ErrorCallback& error_callback) {
+    OnCallMethod(method_call, timeout_ms, response_callback);
+  }
+};
+
+TEST_F(CrasAudioClientTest, OutputMuteChanged) {
+  const bool kSystemMuteOn = false;
+  const bool kUserMuteOn = true;
+  // Create a signal.
+  dbus::Signal signal(cras::kCrasControlInterface,
+                      cras::kOutputMuteChanged);
+  dbus::MessageWriter writer(&signal);
+  writer.AppendBool(kSystemMuteOn);
+  writer.AppendBool(kUserMuteOn);
+
+  // Set expectations.
+  MockObserver observer;
+  EXPECT_CALL(observer, OutputMuteChanged(kUserMuteOn)).Times(1);
+
+  // Add the observer.
+  client_->AddObserver(&observer);
+
+  // Run the signal callback.
+  SendOutputMuteChangedSignal(&signal);
+
+  // Remove the observer.
+  client_->RemoveObserver(&observer);
+
+  EXPECT_CALL(observer, OutputMuteChanged(_)).Times(0);
+
+  // Run the signal callback again and make sure the observer isn't called.
+  SendOutputMuteChangedSignal(&signal);
+
+  message_loop_.RunUntilIdle();
+}
+
+TEST_F(CrasAudioClientTest, InputMuteChanged) {
+  const bool kInputMuteOn = true;
+  // Create a signal.
+  dbus::Signal signal(cras::kCrasControlInterface,
+                      cras::kInputMuteChanged);
+  dbus::MessageWriter writer(&signal);
+  writer.AppendBool(kInputMuteOn);
+
+  // Set expectations.
+  MockObserver observer;
+  EXPECT_CALL(observer, InputMuteChanged(kInputMuteOn)).Times(1);
+
+  // Add the observer.
+  client_->AddObserver(&observer);
+
+  // Run the signal callback.
+  SendInputMuteChangedSignal(&signal);
+
+  // Remove the observer.
+  client_->RemoveObserver(&observer);
+
+  EXPECT_CALL(observer, InputMuteChanged(_)).Times(0);
+
+  // Run the signal callback again and make sure the observer isn't called.
+  SendInputMuteChangedSignal(&signal);
+
+  message_loop_.RunUntilIdle();
+}
+
+TEST_F(CrasAudioClientTest, NodesChanged) {
+  // Create a signal.
+  dbus::Signal signal(cras::kCrasControlInterface,
+                      cras::kNodesChanged);
+  // Set expectations.
+  MockObserver observer;
+  EXPECT_CALL(observer, NodesChanged()).Times(1);
+
+  // Add the observer.
+  client_->AddObserver(&observer);
+
+  // Run the signal callback.
+  SendNodesChangedSignal(&signal);
+
+  // Remove the observer.
+  client_->RemoveObserver(&observer);
+
+  EXPECT_CALL(observer, NodesChanged()).Times(0);
+
+  // Run the signal callback again and make sure the observer isn't called.
+  SendNodesChangedSignal(&signal);
+
+  message_loop_.RunUntilIdle();
+}
+
+TEST_F(CrasAudioClientTest, ActiveOutputNodeChanged) {
+  const uint64_t kNodeId = 10002;
+  // Create a signal.
+  dbus::Signal signal(cras::kCrasControlInterface,
+                      cras::kActiveOutputNodeChanged);
+  dbus::MessageWriter writer(&signal);
+  writer.AppendUint64(kNodeId);
+
+  // Set expectations.
+  MockObserver observer;
+  EXPECT_CALL(observer, ActiveOutputNodeChanged(kNodeId)).Times(1);
+
+  // Add the observer.
+  client_->AddObserver(&observer);
+
+  // Run the signal callback.
+  SendActiveOutputNodeChangedSignal(&signal);
+
+  // Remove the observer.
+  client_->RemoveObserver(&observer);
+  EXPECT_CALL(observer, ActiveOutputNodeChanged(_)).Times(0);
+
+  // Run the signal callback again and make sure the observer isn't called.
+  SendActiveOutputNodeChangedSignal(&signal);
+
+  message_loop_.RunUntilIdle();
+}
+
+TEST_F(CrasAudioClientTest, ActiveInputNodeChanged) {
+  const uint64_t kNodeId = 20002;
+  // Create a signal.
+  dbus::Signal signal(cras::kCrasControlInterface,
+                      cras::kActiveInputNodeChanged);
+  dbus::MessageWriter writer(&signal);
+  writer.AppendUint64(kNodeId);
+
+  // Set expectations.
+  MockObserver observer;
+  EXPECT_CALL(observer, ActiveInputNodeChanged(kNodeId)).Times(1);
+
+  // Add the observer.
+  client_->AddObserver(&observer);
+
+  // Run the signal callback.
+  SendActiveInputNodeChangedSignal(&signal);
+
+  // Remove the observer.
+  client_->RemoveObserver(&observer);
+  EXPECT_CALL(observer, ActiveInputNodeChanged(_)).Times(0);
+
+  // Run the signal callback again and make sure the observer isn't called.
+  SendActiveInputNodeChangedSignal(&signal);
+
+  message_loop_.RunUntilIdle();
+}
+
+TEST_F(CrasAudioClientTest, GetVolumeState) {

[jennyz, 2016/04/14 00:12:31]

GetVolumeState isn't not really useful, we don't need to test it. Actually, we
should remove it from the API, since no one is using it, we never tested it,
cras team may not maintain it either. But that can't be done in a separate cl.

[Qiang(Joe) Xu, 2016/04/14 01:25:49]

done by removing related contents. I do see GetVolumeState is not called by
cras_audio_handler.

+  // Create response.
+  std::unique_ptr<dbus::Response> response(dbus::Response::CreateEmpty());
+  dbus::MessageWriter writer(response.get());
+  const int32_t kOutputVolume = 8;
+  writer.AppendInt32(kOutputVolume);
+  const bool kOutputSystemMute = false;
+  writer.AppendBool(kOutputSystemMute);
+  const int32_t kInputGain = 1;
+  writer.AppendInt32(kInputGain);
+  const bool kInputMute = false;
+  writer.AppendBool(kInputMute);
+  const bool kOutputUserMute = true;
+  writer.AppendBool(kOutputUserMute);
+
+  // Create the expected value.
+  VolumeState expected_volume_state;
+  expected_volume_state.output_volume = kOutputVolume;
+  expected_volume_state.output_system_mute = kOutputSystemMute;
+  expected_volume_state.input_gain = kInputGain;
+  expected_volume_state.input_mute = kInputMute;
+  expected_volume_state.output_user_mute = kOutputUserMute;
+
+  // Set expectations.
+  PrepareForMethodCall(cras::kGetVolumeState,
+                       base::Bind(&ExpectNoArgument),
+                       response.get());
+  // Call method.
+  client_->GetVolumeState(base::Bind(&ExpectVolumeStateResult,
+                                     &expected_volume_state));
+  // Run the message loop.
+  message_loop_.RunUntilIdle();
+}
+
+TEST_F(CrasAudioClientTest, GetNodes) {
+  // Create response.
+  std::unique_ptr<dbus::Response> response(dbus::Response::CreateEmpty());
+  dbus::MessageWriter writer(response.get());
+  dbus::MessageWriter sub_writer(nullptr);
+  dbus::MessageWriter entry_writer(nullptr);
+  // response for kInternalSpeaker

[jennyz, 2016/04/14 00:12:31]

Can the code for adding a audio node be wrapped into a function, so that we
don't have to repeat the complete section of the code each time for adding
another node?

[Qiang(Joe) Xu, 2016/04/14 01:25:49]

done by creating a func WriteNodesToResponse

+  writer.OpenArray("{sv}", &sub_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kIsInputProperty);
+  entry_writer.AppendVariantOfBool(kInternalSpeaker.is_input);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kIdProperty);
+  entry_writer.AppendVariantOfUint64(kInternalSpeaker.id);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kDeviceNameProperty);
+  entry_writer.AppendVariantOfString(kInternalSpeaker.device_name);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kTypeProperty);
+  entry_writer.AppendVariantOfString(kInternalSpeaker.type);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kNameProperty);
+  entry_writer.AppendVariantOfString(kInternalSpeaker.name);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kActiveProperty);
+  entry_writer.AppendVariantOfBool(kInternalSpeaker.active);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kPluggedTimeProperty);
+  entry_writer.AppendVariantOfUint64(kInternalSpeaker.plugged_time);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kMicPositionsProperty);
+  entry_writer.AppendVariantOfString(kInternalSpeaker.mic_positions);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kStableDeviceIdProperty);
+  entry_writer.AppendVariantOfUint64(kInternalSpeaker.stable_device_id);
+  sub_writer.CloseContainer(&entry_writer);
+  writer.CloseContainer(&sub_writer);
+  // response for kInternalMic
+  writer.OpenArray("{sv}", &sub_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kIsInputProperty);
+  entry_writer.AppendVariantOfBool(kInternalMic.is_input);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kIdProperty);
+  entry_writer.AppendVariantOfUint64(kInternalMic.id);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kDeviceNameProperty);
+  entry_writer.AppendVariantOfString(kInternalMic.device_name);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kTypeProperty);
+  entry_writer.AppendVariantOfString(kInternalMic.type);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kNameProperty);
+  entry_writer.AppendVariantOfString(kInternalMic.name);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kActiveProperty);
+  entry_writer.AppendVariantOfBool(kInternalMic.active);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kPluggedTimeProperty);
+  entry_writer.AppendVariantOfUint64(kInternalMic.plugged_time);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kMicPositionsProperty);
+  entry_writer.AppendVariantOfString(kInternalMic.mic_positions);
+  sub_writer.CloseContainer(&entry_writer);
+  sub_writer.OpenDictEntry(&entry_writer);
+  entry_writer.AppendString(cras::kStableDeviceIdProperty);
+  entry_writer.AppendVariantOfUint64(kInternalMic.stable_device_id);
+  sub_writer.CloseContainer(&entry_writer);
+  writer.CloseContainer(&sub_writer);
+
+  // Create the expected value.
+  AudioNodeList expected_node_list;
+  expected_node_list.push_back(kInternalSpeaker);
+  expected_node_list.push_back(kInternalMic);
+
+  // Set expectations.
+  PrepareForMethodCall(cras::kGetNodes,
+                       base::Bind(&ExpectNoArgument),
+                       response.get());
+  // Call method.
+  MockErrorCallback error_callback;
+  client_->GetNodes(base::Bind(&ExpectAudioNodeListResult,
+                               &expected_node_list),
+                    error_callback.GetCallback());
+  EXPECT_CALL(error_callback, Run(_, _)).Times(0);
+  // Run the message loop.
+  message_loop_.RunUntilIdle();
+}
+
+TEST_F(CrasAudioClientTest, SetGlobalOutputChannelRemix) {
+  const int32_t kChannels = 2;
+  const std::vector<double> kMixer = {0, 0.1, 0.5, 1};
+  // Create response.
+  std::unique_ptr<dbus::Response> response(dbus::Response::CreateEmpty());
+
+  // Set expectations.
+  PrepareForMethodCall(cras::kSetGlobalOutputChannelRemix,
+                       base::Bind(&ExpectInt32AndArrayOfDoublesArguments,
+                                  kChannels,
+                                  kMixer),
+                       response.get());
+
+  // Call method.
+  client_->SetGlobalOutputChannelRemix(kChannels, kMixer);
+  // Run the message loop.
+  message_loop_.RunUntilIdle();
+}
+
+}  // namespace chromeos