Add unit test class for RTCCameraVideoCapturer.

webrtc/sdk/objc/Framework/UnitTests/RTCCameraVideoCapturerTests.mm

+/*
+ *  Copyright 2017 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.
+ */
+
+#import <OCMock/OCMock.h>
+#import <UIKit/UIKit.h>
+
+#include "webrtc/base/gunit.h"
+
+#import <WebRTC/RTCCameraVideoCapturer.h>
+#import <WebRTC/RTCDispatcher.h>
+#import <WebRTC/RTCVideoFrame.h>
+
+// Helper method.
+CMSampleBufferRef createMockSampleBufferRef() {

[magjed_webrtc, 2017/04/26 14:12:09]

This is nice! We will probably need something similar for a fake capture. Is the
name 'createMock' here appropriate? It's a real CMSampleBufferRef. Maybe the
name createTestSampleBufferRef is better?

[daniela-webrtc, 2017/04/27 09:40:20]

Done.

+  // This image is already in the testing bundle.
+  UIImage *image = [UIImage imageNamed:@"Default.png"];
+  CGSize size = image.size;
+  CGImageRef imageRef = [image CGImage];
+
+  CVPixelBufferRef pixelBuffer = nullptr;
+  CVPixelBufferCreate(kCFAllocatorDefault, size.width, size.height, kCVPixelFormatType_32ARGB, nil,
+                      &pixelBuffer);
+
+  CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
+  CGContextRef context = CGBitmapContextCreate(nil, size.width, size.height, 8, 8 * size.width,
+                                               rgbColorSpace, kCGImageAlphaPremultipliedFirst);
+
+  CGContextDrawImage(
+      context, CGRectMake(0, 0, CGImageGetWidth(imageRef), CGImageGetHeight(imageRef)), imageRef);
+
+  CGColorSpaceRelease(rgbColorSpace);
+  CGContextRelease(context);
+
+  // We don't really care about the timing.
+  CMSampleTimingInfo timing = {kCMTimeInvalid, kCMTimeInvalid, kCMTimeInvalid};
+  CMVideoFormatDescriptionRef description = nullptr;
+  CMVideoFormatDescriptionCreateForImageBuffer(NULL, pixelBuffer, &description);
+
+  CMSampleBufferRef sampleBuffer = nullptr;
+  CMSampleBufferCreateForImageBuffer(kCFAllocatorDefault, pixelBuffer, YES, NULL, NULL, description,
+                                     &timing, &sampleBuffer);
+  CFRelease(pixelBuffer);
+
+  return sampleBuffer;
+}
+
+@interface RTCCameraVideoCapturer (Tests)<AVCaptureVideoDataOutputSampleBufferDelegate>
+@end
+
+@interface RTCCameraVideoCapturerTests : NSObject
+@property(nonatomic, strong) id delegateMock;
+@property(nonatomic, strong) id deviceMock;
+@property(nonatomic, strong) RTCCameraVideoCapturer *capturer;
+@end
+
+@implementation RTCCameraVideoCapturerTests
+@synthesize delegateMock = _delegateMock;
+@synthesize capturer = _capturer;
+@synthesize deviceMock = _deviceMock;
+
+- (void)setup {
+  self.delegateMock = OCMProtocolMock(@protocol(RTCVideoCapturerDelegate));
+  self.capturer = [[RTCCameraVideoCapturer alloc] initWithDelegate:self.delegateMock];
+  self.deviceMock = [self createDeviceMock];
+}
+
+- (void)tearDown {
+  [self.delegateMock stopMocking];
+  [self.deviceMock stopMocking];
+  self.delegateMock = nil;
+  self.deviceMock = nil;
+  self.capturer = nil;
+}
+
+#pragma mark - utils
+
+- (id)createDeviceMock {
+  return OCMClassMock([AVCaptureDevice class]);
+}
+
+#pragma mark - test cases
+
+- (void)testSetupSession {
+  AVCaptureSession *session = self.capturer.captureSession;
+  EXPECT_TRUE(session != nil);
+  EXPECT_EQ(session.sessionPreset, AVCaptureSessionPresetInputPriority);
+  EXPECT_EQ(session.usesApplicationAudioSession, NO);
+  EXPECT_EQ(session.outputs.count, 1u);
+}
+
+- (void)testSetupSessionOutput {
+  AVCaptureVideoDataOutput *videoOutput = self.capturer.captureSession.outputs[0];
+  EXPECT_TRUE(videoOutput.videoSettings != nil);
+  EXPECT_EQ(videoOutput.alwaysDiscardsLateVideoFrames, NO);
+  EXPECT_EQ(videoOutput.sampleBufferDelegate, self.capturer);
+}
+
+- (void)testSupportedFormatsForDevice {
+  // given
+  id validFormat1 = OCMClassMock([AVCaptureDeviceFormat class]);
+  CMVideoFormatDescriptionRef format;
+  CMVideoFormatDescriptionCreate(nil, kCVPixelFormatType_420YpCbCr8PlanarFullRange, 123, 456, nil,
+                                 &format);
+  OCMStub([validFormat1 formatDescription]).andReturn(format);
+
+  id validFormat2 = OCMClassMock([AVCaptureDeviceFormat class]);
+  CMVideoFormatDescriptionCreate(nil, kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange, 123, 456,
+                                 nil, &format);
+  OCMStub([validFormat2 formatDescription]).andReturn(format);
+
+  id invalidFormat = OCMClassMock([AVCaptureDeviceFormat class]);
+  CMVideoFormatDescriptionCreate(nil, kCVPixelFormatType_422YpCbCr8_yuvs, 123, 456, nil, &format);
+  OCMStub([invalidFormat formatDescription]).andReturn(format);
+
+  NSArray *formats = @[ validFormat1, validFormat2, invalidFormat ];
+  OCMStub([self.deviceMock formats]).andReturn(formats);
+
+  // when
+  NSArray *supportedFormats = [RTCCameraVideoCapturer supportedFormatsForDevice:self.deviceMock];
+
+  // then
+  EXPECT_EQ(supportedFormats.count, 2u);
+  EXPECT_TRUE([supportedFormats containsObject:validFormat1]);
+  EXPECT_TRUE([supportedFormats containsObject:validFormat2]);
+  // cleanup
+  [validFormat1 stopMocking];
+  [validFormat2 stopMocking];
+  [invalidFormat stopMocking];
+  validFormat1 = nil;
+  validFormat2 = nil;
+  invalidFormat = nil;
+}
+
+- (void)testCaptureDevices {
+  OCMStub([self.deviceMock devicesWithMediaType:AVMediaTypeVideo]).andReturn(@[ [NSObject new] ]);

[magjed_webrtc, 2017/04/26 14:12:08]

Remove duplicate line

[daniela-webrtc, 2017/04/27 09:40:20]

This line is not duplicate. The first one mocks AVMediaTypeVideo the second
AVMediaTypeAudio devices.

[magjed_webrtc, 2017/04/27 14:48:12]

Acknowledged.

+  OCMStub([self.deviceMock devicesWithMediaType:AVMediaTypeAudio]).andReturn(@[ [NSObject new] ]);
+
+  NSArray *captureDevices = [RTCCameraVideoCapturer captureDevices];
+
+  EXPECT_EQ(captureDevices.count, 1u);
+}
+
+- (void)testDelegateCallbackNotCalledWhenInvalidBuffer {
+  // given
+  CMSampleBufferRef sampleBuffer = nullptr;
+  [[self.delegateMock reject] capturer:[OCMArg any] didCaptureVideoFrame:[OCMArg any]];
+
+  // when
+
+  [self.capturer captureOutput:self.capturer.captureSession.outputs[0]
+         didOutputSampleBuffer:sampleBuffer
+                fromConnection:nil];
+
+  // then
+  [self.delegateMock verify];
+}
+
+- (void)testDelegateCallbackWithValideBufferAndOrientationUpdate {

[magjed_webrtc, 2017/04/26 14:12:08]

spelling nit: Valide

[daniela-webrtc, 2017/04/27 09:40:20]

Done.

+  // given
+  UIDevice *currentDeviceMock = OCMClassMock([UIDevice class]);
+  // UpsideDown -> RTCVideoRotation_270.
+  OCMStub(currentDeviceMock.orientation).andReturn(UIDeviceOrientationPortraitUpsideDown);
+  id classMock = OCMClassMock([UIDevice class]);
+  OCMStub([classMock currentDevice]).andReturn(currentDeviceMock);
+
+  CMSampleBufferRef sampleBuffer = createMockSampleBufferRef();
+
+  // then
+  [[self.delegateMock expect] capturer:self.capturer
+                  didCaptureVideoFrame:[OCMArg checkWithBlock:^BOOL(RTCVideoFrame *expectedFrame) {
+                    EXPECT_EQ(expectedFrame.rotation, RTCVideoRotation_270);
+                    return YES;
+                  }]];
+
+  // when
+  NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
+  [center postNotificationName:UIDeviceOrientationDidChangeNotification object:nil];
+
+  // We need to wait for the dispatch to finish.
+  WAIT(0, 1000);

[magjed_webrtc, 2017/04/26 14:12:09]

I think it's preferable in this case to expose
'(void)updateOrientation:(UIDeviceOrientation)orientation;' and call that
directly instead like you used to do.

[daniela-webrtc, 2017/04/27 09:40:20]

I'd prefer to keep this test as is because it tests the notification observing
and the orientation change. It's slightly more complicated but it provides
better coverage. 

[magjed_webrtc, 2017/04/27 14:48:12]

Ok, it's the WAIT in particular I don't like. Is it possible to wait only until
the dispatch has finished instead?

+
+  [self.capturer captureOutput:self.capturer.captureSession.outputs[0]
+         didOutputSampleBuffer:sampleBuffer
+                fromConnection:nil];
+
+  [self.delegateMock verify];
+
+  [(id)currentDeviceMock stopMocking];
+  currentDeviceMock = nil;
+  [classMock stopMocking];
+  classMock = nil;
+  CFRelease(sampleBuffer);
+}
+@end
+
+TEST(RTCCameraVideoCapturerTests, SetupSession) {
+  RTCCameraVideoCapturerTests *test = [[RTCCameraVideoCapturerTests alloc] init];
+  [test setup];
+  [test testSetupSession];
+  [test tearDown];
+}
+
+TEST(RTCCameraVideoCapturerTests, SetupSessionOutput) {
+  RTCCameraVideoCapturerTests *test = [[RTCCameraVideoCapturerTests alloc] init];
+  [test setup];
+  [test testSetupSessionOutput];
+  [test tearDown];
+}
+
+TEST(RTCCameraVideoCapturerTests, SupportedFormatsForDevice) {
+  RTCCameraVideoCapturerTests *test = [[RTCCameraVideoCapturerTests alloc] init];
+  [test setup];
+  [test testSupportedFormatsForDevice];
+  [test tearDown];
+}
+
+TEST(RTCCameraVideoCapturerTests, CaptureDevices) {
+  RTCCameraVideoCapturerTests *test = [[RTCCameraVideoCapturerTests alloc] init];
+  [test setup];
+  [test testCaptureDevices];
+  [test tearDown];
+}
+
+TEST(RTCCameraVideoCapturerTests, DelegateCallbackNotCalledWhenInvalidBuffer) {
+  RTCCameraVideoCapturerTests *test = [[RTCCameraVideoCapturerTests alloc] init];
+  [test setup];
+  [test testDelegateCallbackNotCalledWhenInvalidBuffer];
+  [test tearDown];
+}
+
+TEST(RTCCameraVideoCapturerTests, DelegateCallbackWithValideBufferAndOrientationUpdate) {
+  RTCCameraVideoCapturerTests *test = [[RTCCameraVideoCapturerTests alloc] init];
+  [test setup];
+  [test testDelegateCallbackWithValideBufferAndOrientationUpdate];
+  [test tearDown];
+}