Add unit tests for avfoundation format mapper functions and fix wrong implementation.

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

+/*
+ *  Copyright 2016 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 <Foundation/Foundation.h>
+#import <OCMock/OCMock.h>
+#include "avfoundationformatmapper.h"
+#include "webrtc/base/gunit.h"
+
+// Width and height don't play any role so lets use predefined values throughout
+// the tests.
+static const int kFormatWidth = 789;
+static const int kFormatHeight = 987;
+
+// Hardcoded framrate to be used throughout the tests.
+static const int kFramerate = 30;
+
+// Same width and height is used so it's ok to expect same cricket::VideoFormat
+static cricket::VideoFormat SupportedCricketVideoFormat() {

[magjed_webrtc, 2016/11/29 13:34:01]

It should be possible to just have a constant for this:
const cricket::VideoFormat kSupportedCricketVideoFormat(
    kFormatWidth, kFormatHeight,
    cricket::VideoFormat::FpsToInterval(kFramerate),
    cricket::FOURCC_NV12);

[daniela-webrtc, 2016/11/29 16:13:57]

Done.

+  return cricket::VideoFormat(kFormatWidth, kFormatHeight,
+                              cricket::VideoFormat::FpsToInterval(kFramerate),
+                              cricket::FOURCC_NV12);
+}
+
+// Mock class for AVCaptureDeviceFormat.
+// Custom implementation needed because OCMock cannot handle the
+// CMVideoDescriptionRef mocking.
+@interface AVCaptureDeviceFormatMock : NSObject {
+  CMVideoFormatDescriptionRef _format;
+  OCMockObject *_rangeMock;
+}
+
+- (instancetype)initWithMediaSubtype:(FourCharCode)subtype
+                              minFps:(float)minFps
+                              maxFps:(float)maxFps;
++ (instancetype)validFormat;
++ (instancetype)invalidFpsFormat;
++ (instancetype)invalidMediaSubtypeFormat;
+
+@end
+
+@implementation AVCaptureDeviceFormatMock
+
+- (instancetype)initWithMediaSubtype:(FourCharCode)subtype
+                              minFps:(float)minFps
+                              maxFps:(float)maxFps {
+  if (self = [super init]) {
+    CMVideoFormatDescriptionCreate(nil, subtype, kFormatWidth, kFormatHeight,
+                                   nil, &_format);
+    // We can use OCMock for the range.
+    _rangeMock = [OCMockObject mockForClass:[AVFrameRateRange class]];
+    [[[_rangeMock stub] andReturnValue:@(minFps)] minFrameRate];
+    [[[_rangeMock stub] andReturnValue:@(maxFps)] maxFrameRate];
+  }
+
+  return self;
+}
+
++ (instancetype)validFormat {
+  AVCaptureDeviceFormatMock *instance = [[AVCaptureDeviceFormatMock alloc]
+      initWithMediaSubtype:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange
+                    minFps:0.0
+                    maxFps:30.0];
+  return instance;
+}
+
++ (instancetype)invalidFpsFormat {
+  AVCaptureDeviceFormatMock *instance = [[AVCaptureDeviceFormatMock alloc]
+      initWithMediaSubtype:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange
+                    minFps:0.0
+                    maxFps:22.0];
+  return instance;
+}
+
++ (instancetype)invalidMediaSubtypeFormat {
+  AVCaptureDeviceFormatMock *instance = [[AVCaptureDeviceFormatMock alloc]
+      initWithMediaSubtype:kCVPixelFormatType_420YpCbCr8Planar
+                    minFps:0.0
+                    maxFps:60.0];
+  return instance;
+}
+
+- (void)dealloc {
+  if (_rangeMock != nil) {
+    [_rangeMock dealloc];
+    _rangeMock = nil;
+  }
+  if (_format != nil) {
+    CFRelease(_format);
+    _format = nil;
+  }
+  [super dealloc];
+}
+
+// Redefinition of AVCaptureDevice methods we want to mock.
+- (CMVideoFormatDescriptionRef)formatDescription {
+  return _format;
+}
+
+- (NSArray *)videoSupportedFrameRateRanges {
+  return @[ _rangeMock ];
+}
+
+@end
+
+class AVFormatMapperTest : public ::testing::Test {
+ protected:
+  void testSuportedCricketFormatsWithInvalidFramerateFormats() {
+    // given
+    id mockDevice = [OCMockObject mockForClass:[AVCaptureDevice class]];
+
+    // Valid media subtype, invalid framerate
+    AVCaptureDeviceFormatMock* mockOne =
+        [AVCaptureDeviceFormatMock invalidFpsFormat];
+    // Valid media subtype, valid framerate
+    AVCaptureDeviceFormatMock* mockTwo =
+        [AVCaptureDeviceFormatMock validFormat];
+
+    [[[mockDevice stub] andReturn:@[ mockOne, mockTwo ]] formats];
+
+    cricket::VideoFormat expected = SupportedCricketVideoFormat();
+
+    // when
+    std::set<cricket::VideoFormat> result =
+        webrtc::GetSupportedVideoFormatsForDevice(mockDevice);
+
+    // then
+    EXPECT_EQ(1, result.size());
+    EXPECT_EQ(1u, result.count(expected));
+  }
+
+  void testSuportedCricketFormatsWithInvalidMediaSubtypeFormats() {
+    // given
+    id mockDevice = [OCMockObject mockForClass:[AVCaptureDevice class]];
+
+    // Invalid media subtype, valid framerate
+    AVCaptureDeviceFormatMock* mockOne =
+        [AVCaptureDeviceFormatMock invalidMediaSubtypeFormat];
+    // Valid media subtype, valid framerate
+    AVCaptureDeviceFormatMock* mockTwo =
+        [AVCaptureDeviceFormatMock validFormat];
+
+    [[[mockDevice stub] andReturn:@[ mockOne, mockTwo ]] formats];
+
+    cricket::VideoFormat expected = SupportedCricketVideoFormat();
+
+    // when
+    std::set<cricket::VideoFormat> result =
+        webrtc::GetSupportedVideoFormatsForDevice(mockDevice);
+
+    // then
+    EXPECT_EQ(1, result.size());
+    EXPECT_EQ(1u, result.count(expected));
+  }
+
+  void testSuportedCricketFormats() {
+    // given
+    id mockDevice = [OCMockObject mockForClass:[AVCaptureDevice class]];
+
+    // valid media subtype, valid framerate
+    AVCaptureDeviceFormatMock* mockOne =
+        [AVCaptureDeviceFormatMock validFormat];
+    [[[mockDevice stub] andReturn:@[ mockOne ]] formats];
+
+    cricket::VideoFormat expectedFormat = SupportedCricketVideoFormat();
+
+    // when
+    std::set<cricket::VideoFormat> result =
+        webrtc::GetSupportedVideoFormatsForDevice(mockDevice);
+
+    // then
+    EXPECT_EQ(1, result.size());
+
+    // make sure the set has the expected format
+    EXPECT_EQ(1u, result.count(expectedFormat));
+  }
+
+  void testAVFormatForCricketFormat() {

[magjed_webrtc, 2016/11/29 13:34:01]

nit: I would like to rename this test to something like
testMediaSubtypePreference.

[daniela-webrtc, 2016/11/29 16:13:57]

Done.

+    // given
+    id mockDevice = [OCMockObject mockForClass:[AVCaptureDevice class]];
+
+    // valid media subtype, valid framerate
+    AVCaptureDeviceFormatMock* mockOne = [[AVCaptureDeviceFormatMock alloc]
+        initWithMediaSubtype:kCVPixelFormatType_420YpCbCr8BiPlanarFullRange
+                      minFps:0.0
+                      maxFps:30.0];
+
+    // valid media subtype, valid framerate.
+    // This media subtype should be the preffered one.
+    AVCaptureDeviceFormatMock* mockTwo = [[AVCaptureDeviceFormatMock alloc]
+        initWithMediaSubtype:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange
+                      minFps:0.0
+                      maxFps:30.0];
+
+    [[[mockDevice stub] andReturnValue:@(YES)]
+        lockForConfiguration:[OCMArg setTo:nil]];
+    [[mockDevice stub] unlockForConfiguration];
+
+    [[[mockDevice stub] andReturn:@[ mockOne, mockTwo ]] formats];
+
+    cricket::VideoFormat inputFormat = SupportedCricketVideoFormat();
+
+    // to verify
+    [[mockDevice expect] setActiveFormat:(AVCaptureDeviceFormat*)mockTwo];
+    [[mockDevice expect]
+        setActiveVideoMinFrameDuration:CMTimeMake(1, kFramerate)];
+
+    // when
+    bool resultFormat =
+        webrtc::SetFormatForCaptureDevice(mockDevice, nil, inputFormat);
+
+    // then
+    EXPECT_TRUE(resultFormat);
+    [mockDevice verify];
+  }
+
+  void testSetFormatWhenDeviceCannotLock() {
+    // given
+    id mockDevice = [OCMockObject mockForClass:[AVCaptureDevice class]];
+    [[[mockDevice stub] andReturnValue:@(NO)]
+        lockForConfiguration:[OCMArg setTo:nil]];
+
+    [[[mockDevice stub] andReturn:@[]] formats];
+
+    // when
+    bool resultFormat = webrtc::SetFormatForCaptureDevice(
+        mockDevice, nil, cricket::VideoFormat());
+
+    // then
+    EXPECT_FALSE(resultFormat);
+  }
+
+  void testSetFormatWhenFormatIsIncompatible() {
+    // given
+    id mockDevice = [OCMockObject mockForClass:[AVCaptureDevice class]];
+    [[[mockDevice stub] andReturn:@[]] formats];
+    [[[mockDevice stub] andReturnValue:@(YES)]
+        lockForConfiguration:[OCMArg setTo:nil]];
+
+    NSException* exception =
+        [NSException exceptionWithName:@"Test exception"
+                                reason:@"Raised from unit tests"
+                              userInfo:nil];
+    [[[mockDevice stub] andThrow:exception] setActiveFormat:[OCMArg any]];
+    [[mockDevice expect] unlockForConfiguration];
+
+    // when
+    bool resultFormat = webrtc::SetFormatForCaptureDevice(
+        mockDevice, nil, cricket::VideoFormat());
+
+    // then
+    EXPECT_FALSE(resultFormat);
+    [mockDevice verify];
+  }
+};
+
+TEST_F(AVFormatMapperTest, SuportedCricketFormatsWithInvalidFramerateFormats) {
+  testSuportedCricketFormatsWithInvalidFramerateFormats();
+}
+
+TEST_F(AVFormatMapperTest, SuportedCricketFormatsWithInvalidFormats) {
+  testSuportedCricketFormatsWithInvalidMediaSubtypeFormats();
+}
+
+TEST_F(AVFormatMapperTest, SuportedCricketFormats) {
+  testSuportedCricketFormats();
+}
+
+TEST_F(AVFormatMapperTest, AVFormatForCricketFormat) {
+  testAVFormatForCricketFormat();
+}
+
+TEST_F(AVFormatMapperTest, SetFormatWhenDeviceCannotLock) {
+  testSetFormatWhenDeviceCannotLock();
+}
+
+TEST_F(AVFormatMapperTest, SetFormatWhenFormatIsIncompatible) {
+  testSetFormatWhenFormatIsIncompatible();
+}