Question

上下文： 我正在尝试使用GMock模拟OpenCV-C ++类。

问题：

我无法对要使用cv :: Mat并返回cv :: Mat的函数使用EXPECT_CALL方法。编译器说gmock-matcher 无法从cv :: MatExpr转换为bool作为回报。

。

以下是编译期间的详细错误消息。

In file included from /home/arun/Documents /LaneDetection/test/../vendor/googletest/googlemock/include/gmock/gmock-spec-builders.h:75:0, from /home/arun/Documents/LaneDetection/test/../vendor/googletest/googlemock/include/gmock/gmock-generated-function-mockers.h:43, from /home/arun/Documents/LaneDetection/test/../vendor/googletest/googlemock/include/gmock/gmock.h:61, from /home/arun/Documents/LaneDetection/test/test.cpp:32: /home/arun/Documents/LaneDetection/test/../vendor /googletest/googlemock/include/gmock/gmock-matchers.h: In instantiation of ‘bool testing::internal::AnyEq::operator()(const A&, const B&) const [with A = cv::Mat; B = cv::Mat]’: /home/arun/Documents/LaneDetection/test/../vendor/googletest/googlemock/include/gmock/gmock-matchers.h:908:18: required from ‘bool testing::internal::ComparisonBase<D, Rhs, Op>::Impl<Lhs>::MatchAndExplain(Lhs, testing::MatchResultListener*) const [with Lhs = cv::Mat; D = testing::internal::EqMatcher<cv::Mat>; Rhs = cv::Mat; Op = testing::internal::AnyEq]’ /home/arun/Documents/LaneDetection/test/test.cpp:77:39: required from here /home/arun/Documents/LaneDetection/test/../vendor/googletest/googlemock/include/gmock/gmock-matchers.h:204:63: error: cannot convert ‘cv::MatExpr’ to ‘bool’ in return bool operator()(const A& a, const B& b) const { return a == b; } ^ test/CMakeFiles/cpp-test.dir/build.make:86: recipe for target 'test/CMakeFiles/cpp-test.dir/test.cpp.o' failed make[2]: *** [test/CMakeFiles/cpp-test.dir/test.cpp.o] Error 1 CMakeFiles/Makefile2:178: recipe for target 'test/CMakeFiles/cpp-test.dir/all' failed make[1]: *** [test/CMakeFiles/cpp-test.dir/all] Error 2 Makefile:127: recipe for target 'all' failed make: *** [all] Error 2

以下是我的模拟类：

Thresholder.hpp

class Thresholder { public: Thresholder() {} virtual ~Thresholder() {} virtual cv::Mat convertToLab(cv::Mat smoothImg); private: cv::Mat inputImg; // < Container used for storing input image cv::Mat labImage; // < Container for LAB converted input image };

Thresholder.cpp

cv::Mat Thresholder::convertToLab(cv::Mat smoothImg) { inputImg = smoothImg; cv::cvtColor(inputImg, labImage, cv::COLOR_BGR2Lab); return labImage; }

test.cpp

class MockThresholder : public Thresholder { public: MOCK_METHOD1(convertToLab, cv::Mat(cv::Mat smoothImg)); }; /* *@brief : Creating test cases for mock class */ TEST(MockTest, ThreshTest) { MockThresholder ThreshMock; cv::Mat dummyXY = cv::Mat::ones(100, 100, CV_8UC3); EXPECT_CALL(ThreshMock, convertToLab(dummyXY)) .Times(1) .WillOnce(::testing::Return(dummyXY));}

问题：

似乎没有在线资源可以演示如何通过gmock有效地使用OpenCV和C ++。是否可以分享一些有关如何测试在GMock中返回cv :: Mat的C ++类方法的演示？

Answer 1

这里的问题不是返回类型，而是预期的调用。具体来说，EXPECT_CALL(ThreshMock, convertToLab(dummyXY))使GMock检查被叫参数是否确实等于dummyXY。默认情况下，它使用==比较运算符。

但是OpenCV声明它们的比较为cv::MatExpr operator==(cv::Mat, cv::Mat)。它返回布尔值矩阵，而不是bool。

因此，您必须告诉GMock如何将您的预期通话与a custom matcher相匹配。您可以使用MATCHER_...宏来创建匹配器：

MATCHER_P(cvMatMatches, expected, "Match arg cvMat to be equal to expected") {
  if (arg.size() != expected.size()) {
    return false;
  }
  auto differingElems = (arg != expected);
  return cv::countNonZero(differingElems) == 0;
}

您的测试代码变为：

TEST(MockTest, ThreshTest) {
  MockThresholder ThreshMock;
  cv::Mat dummyXY = cv::Mat::ones(100, 100, CV_8U);
  EXPECT_CALL(ThreshMock, convertToLab(cvMatMatches(dummyXY)))
      .Times(1)
      .WillOnce(::testing::Return(dummyXY));

  ThreshMock.convertToLab(dummyXY);
}

GMock：错误：无法将“ cv :: MatExpr”转换为“ bool”作为回报

1 个答案: