[WebMIDI] Introduce UsbMidi{Input, Output}Stream.

media/midi/usb_midi_input_stream_unittest.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/midi/usb_midi_input_stream.h"
+
+#include <vector>
+
+#include "media/midi/usb_midi_device.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+
+namespace {
+
+using ::testing::InSequence;
+using ::testing::StrictMock;
+
+typedef ::testing::MockFunction<void(int)> Checkpoint;  // NOLINT
+
+template<typename T, size_t N>
+std::vector<T> ToVector(const T((&array)[N])) {
+  return std::vector<T>(array, array + N);
+}
+
+class TestUsbMidiDevice : public UsbMidiDevice {
+ public:
+  TestUsbMidiDevice() {}
+  virtual ~TestUsbMidiDevice() {}
+  virtual std::vector<uint8> GetDescriptor() OVERRIDE {
+    return std::vector<uint8>();
+  }
+  virtual void Send(int endpoint_number,
+                    const std::vector<uint8>& data) OVERRIDE {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TestUsbMidiDevice);
+};
+
+class MockDelegate : public UsbMidiInputStream::Delegate {
+ public:
+  MockDelegate() {}
+  virtual ~MockDelegate() {}
+  virtual void OnReceivedData(size_t jack_index,
+                              const uint8* data,
+                              size_t size,
+                              double timestamp) OVERRIDE {
+    // In order to use gmock parameter matching,
+    // we define and use OnReceiveData with std::vector<uint8>.
+    OnReceivedData(jack_index,
+                   std::vector<uint8>(data, data + size),
+                   timestamp);
+  }
+
+  MOCK_METHOD3(OnReceivedData, void(size_t,
+                                    const std::vector<uint8>&,
+                                    double));
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MockDelegate);
+};
+
+class UsbMidiInputStreamTest : public ::testing::Test {
+ protected:
+  UsbMidiInputStreamTest()
+      : device1_(new TestUsbMidiDevice),
+        device2_(new TestUsbMidiDevice),
+        delegate_(new StrictMock<MockDelegate>) {
+    std::vector<UsbMidiJack> jacks;
+
+    jacks.push_back(UsbMidiJack(device1_.get(),
+                                84,  // jack_id
+                                4,  // cable_number
+                                135));  // endpoint_address
+    jacks.push_back(UsbMidiJack(device2_.get(),
+                                85,
+                                5,
+                                137));
+    jacks.push_back(UsbMidiJack(device2_.get(),
+                                84,
+                                4,
+                                135));
+    jacks.push_back(UsbMidiJack(device1_.get(),
+                                85,
+                                5,
+                                135));
+
+    stream_.reset(new UsbMidiInputStream(jacks, delegate_.get()));
+  }
+
+  scoped_ptr<TestUsbMidiDevice> device1_;

[scherkus (not reviewing), 2014/01/16 21:55:52]

it doesn't look like any of these need to be scoped_ptr<>

[yhirano, 2014/01/20 09:12:19]

Do you mean they should be objects rather than pointers?

[scherkus (not reviewing), 2014/01/21 21:25:25]

yep!

+  scoped_ptr<TestUsbMidiDevice> device2_;
+  scoped_ptr<MockDelegate> delegate_;
+  scoped_ptr<UsbMidiInputStream> stream_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(UsbMidiInputStreamTest);
+};
+
+TEST_F(UsbMidiInputStreamTest, UnknownMessage) {
+  uint8 data[] = {
+    0x40, 0xff, 0xff, 0xff,
+    0x41, 0xff, 0xff, 0xff,
+  };
+  stream_->OnReceivedData(device1_.get(), 7, data, arraysize(data), 0);
+}
+
+TEST_F(UsbMidiInputStreamTest, SystemCommonMessage) {
+  uint8 data[] = {
+    0x45, 0xf8, 0x00, 0x00,
+    0x42, 0xf3, 0x22, 0x00,
+    0x43, 0xf2, 0x33, 0x44,
+  };
+  uint8 expected1[] = { 0xf8, };
+  uint8 expected2[] = { 0xf3, 0x22, };
+  uint8 expected3[] = { 0xf2, 0x33, 0x44, };
+
+  {
+    InSequence s;
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected1), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected2), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected3), 0));

[scherkus (not reviewing), 2014/01/16 21:55:52]

These days I heavily discourage writing tests using gmock w/ InSequence. While
it seems convenient ... it makes the tests extremely fragile and extremely
difficult to debug when they fail.

For this style of test where you want to validate some output data given a set
of input, I find having human-readable test expectations more maintainable.

Example:

class TestDelegate : public UsbMidiInputStream::Delegate {
  std::string received_data() { return received_data_; }

  // Convert received data into a human readable string.
  void OnReceivedData(size_t jack_index, const uint8* data,
                      size_t size, double timestamp) OVERRIDE {
    received_data_ += base::StringPrintf("%zu { ", jack_index);
    for (size_t i = 0; i < size; ++i) {
      received_data_ += base::StringPrintf("0x%02x ", data[i]);
    }
    received_data_ += base::StringPrintf("} %f\n", timestamp);
  }

 private:
  std::string received_data_;
};

TEST_F(UsbMidiInputStreamTest, SystemCommonMessage) {
  uint8 data[] = {
    0x45, 0xf8, 0x00, 0x00,
    0x42, 0xf3, 0x22, 0x00,
    0x43, 0xf2, 0x33, 0x44,
  };

  stream_->OnReceivedData(device1_.get(), 7, data, arraysize(data), 0);

  EXPECT_EQ(
      "0 { 0xf8 } 0.000000\n"
      "0 { 0xf3 0x22 } 0.000000\n"
      "0 { 0xf2 0x33 0x44 } 0.000000\n",
      delegate_.received_data());
}


You capture the same amount of detail in your test with each line of text
corresponding to a call to OnReceivedData(), except now when the test fails it's
immediately obvious what changed (e.g., # of times OnReceivedData() was called,
which parameters changed, how the data is different).

[yhirano, 2014/01/20 09:12:19]

Done.

+  }
+
+  stream_->OnReceivedData(device1_.get(), 7, data, arraysize(data), 0);
+}
+
+TEST_F(UsbMidiInputStreamTest, SystemExclusiveMessage) {
+  uint8 data[] = {
+    0x44, 0xf0, 0x11, 0x22,
+    0x45, 0xf7, 0x00, 0x00,
+    0x46, 0xf0, 0xf7, 0x00,
+    0x47, 0xf0, 0x33, 0xf7,
+  };
+  uint8 expected1[] = { 0xf0, 0x11, 0x22, };
+  uint8 expected2[] = { 0xf7, };
+  uint8 expected3[] = { 0xf0, 0xf7, };
+  uint8 expected4[] = { 0xf0, 0x33, 0xf7, };
+
+  {
+    InSequence s;
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected1), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected2), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected3), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected4), 0));
+  }
+
+  stream_->OnReceivedData(device1_.get(), 7, data, arraysize(data), 0);
+}
+
+TEST_F(UsbMidiInputStreamTest, ChannelMessage) {
+  uint8 data[] = {
+    0x48, 0x80, 0x11, 0x22,
+    0x49, 0x90, 0x33, 0x44,
+    0x4a, 0xa0, 0x55, 0x66,
+    0x4b, 0xb0, 0x77, 0x88,
+    0x4c, 0xc0, 0x99, 0x00,
+    0x4d, 0xd0, 0xaa, 0x00,
+    0x4e, 0xe0, 0xbb, 0xcc,
+  };
+  uint8 expected1[] = { 0x80, 0x11, 0x22, };
+  uint8 expected2[] = { 0x90, 0x33, 0x44, };
+  uint8 expected3[] = { 0xa0, 0x55, 0x66, };
+  uint8 expected4[] = { 0xb0, 0x77, 0x88, };
+  uint8 expected5[] = { 0xc0, 0x99, };
+  uint8 expected6[] = { 0xd0, 0xaa, };
+  uint8 expected7[] = { 0xe0, 0xbb, 0xcc, };
+
+  {
+    InSequence s;
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected1), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected2), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected3), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected4), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected5), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected6), 0));
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected7), 0));
+  }
+
+  stream_->OnReceivedData(device1_.get(), 7, data, arraysize(data), 0);
+}
+
+TEST_F(UsbMidiInputStreamTest, SingleByteMessage) {
+  uint8 data[] = {
+    0x4f, 0xf8, 0x00, 0x00,
+  };
+
+  uint8 expected[] = { 0xf8, };
+
+  {
+    InSequence s;
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected), 0));
+  }
+
+  stream_->OnReceivedData(device1_.get(), 7, data, arraysize(data), 0);
+}
+
+TEST_F(UsbMidiInputStreamTest, DispatchForMultipleCables) {
+  uint8 data[] = {
+    0x4f, 0xf8, 0x00, 0x00,
+    0x5f, 0xfa, 0x00, 0x00,
+    0x6f, 0xfb, 0x00, 0x00,
+  };
+  uint8 expected1[] = { 0xf8, };
+  uint8 expected2[] = { 0xfa, };
+
+  {
+    InSequence s;
+    EXPECT_CALL(*delegate_, OnReceivedData(0, ToVector(expected1), 99));
+    EXPECT_CALL(*delegate_, OnReceivedData(3, ToVector(expected2), 99));
+  }
+
+  stream_->OnReceivedData(device1_.get(), 7, data, arraysize(data), 99);
+}
+
+TEST_F(UsbMidiInputStreamTest, DispatchForDevice2) {
+  uint8 data[] = { 0x4f, 0xf8, 0x00, 0x00 };
+  uint8 expected[] = { 0xf8, };
+
+  {
+    InSequence s;
+    EXPECT_CALL(*delegate_, OnReceivedData(2, ToVector(expected), 99));
+  }
+
+  stream_->OnReceivedData(device2_.get(), 7, data, arraysize(data), 99);
+}
+
+}  // namespace
+
+}  // namespace media