c++ - Google Mock 测试类的真实行为

Question

我是 google test 和 google mock 的新手，所以我还是有点困惑。我只是尝试用整数加法、乘法和除法实现一个简单的计算器，并为它创建一个遵循真实行为的模拟。我该如何解决或哪里做错了？

另外你能给我解释一下我如何确定它是在模拟原始类而不是直接调用原始类吗？先谢谢你。

这是 CBasicMath.hpp:

#ifndef BASIC_MATH_HPP__
#define BASIC_MATH_HPP__

class CBasicMath
{
public:
    CBasicMath(){}
    virtual ~CBasicMath() {}
    virtual int Addition(int x, int y);
    virtual int Multiply(int x, int y);
    virtual int Divide(int x, int y);
};

#endif //BASIC_MATH_HPP__

这是 CBasicMath.cpp:

#include "CBasicMath.hpp"

int CBasicMath::Addition(int x, int y)
{
   return (x + y);
}

int CBasicMath::Multiply(int x, int y)
{
   return (x * y);
}

int CBasicMath::Divide(int x, int y)
{
   return (x / y);
}

这里是 mock_basic_test.cpp:

#include "gmock/gmock.h"
#include "CBasicMath.cpp"

using ::testing::_;
using ::testing::AtLeast;
using ::testing::Invoke;

class MockBasicTest : public CBasicMath {
public:
    MockBasicTest() {
    // By default, all calls are delegated to the real object.
    ON_CALL(*this, Addition(_))
        .WillByDefault(Invoke(&real_, &CBasicMath::Addition));
    ON_CALL(*this, Multiply(_))
        .WillByDefault(Invoke(&real_, &CBasicMath::Multiply));
    ON_CALL(*this, Divide(_))
        .WillByDefault(Invoke(&real_, &CBasicMath::Divide));
  }
    MOCK_METHOD2(Addition, int(int x, int y));
    MOCK_METHOD2(Multiply, int(int x, int y));
    MOCK_METHOD2(Divide, int(int x, int y));
private:
    CBasicMath real_;
};

这是 TestBasicMath:

#include "mock_basic_test.h"
#include "gtest/gtest.h"
#include "gmock/gmock.h"

class BasicMathTest : public ::testing::Test {
protected:
    BasicMathTest() {}

    virtual ~BasicMathTest() {}

    virtual void SetUp() {
        mTestObj = new CBasicMath();
    }

    virtual void TearDown() {
        delete mTestObj;
    }
    CBasicMath *mTestObj;
};

TEST_F(BasicMathTest, testAddition) {
    MockBasicTest basictest;
    EXPECT_CALL(basictest, Addition(2,3))
        .Times(1);
    EXPECT_EQ(5,basictest.Addition(2,3));
}

TEST_F(BasicMathTest, testMultiply) {
    EXPECT_EQ(6,mTestObj->Multiply(2,3));
}

TEST_F(BasicMathTest, testDivide) {
    EXPECT_EQ(6,mTestObj->Divide(6,1));
}

int main(int argc, char **argv) {
    ::testing::InitGoogleTest(&argc, argv);
    return RUN_ALL_TESTS();
}

对于所有三个函数，它都会给我如下错误:

In file included from /home/gmock-1.7.0/include/gmock/gmock-generated-function-mockers.h:43:0,
                 from /home/gmock-1.7.0/include/gmock/gmock.h:61,
                 from mock_basic_test.h:1,
                 from TestBasicMath_GoogleTest.cpp:1:
mock_basic_test.h: In constructor ‘MockBasicTest::MockBasicTest()’:
mock_basic_test.h:12:30: error: no matching function for call to ‘MockBasicTest::gmock_Addition(const testing::internal::AnythingMatcher&)’
     ON_CALL(*this, Addition(_))
                             ^
mock_basic_test.h:12:30: note: candidate is:
In file included from /home/gmock-1.7.0/include/gmock/gmock.h:61:0,
                 from mock_basic_test.h:1,
                 from TestBasicMath_GoogleTest.cpp:1:
mock_basic_test.h:19:2: note: testing::internal::MockSpec<int(int, int)>&MockBasicTest::gmock_Addition(const testing::Matcher<int>&, const testing::Matcher<int>&)
  MOCK_METHOD2(Addition, int(int x, int y));
  ^
mock_basic_test.h:19:2: note:   candidate expects 2 arguments, 1 provided

再次感谢您的帮助。

Answer 1

在你的模拟类构造函数代码中

ON_CALL(*this, Addition(_))
    .WillByDefault(Invoke(&real_, &CBasicMath::Addition));

匹配器(_)的数量需要与为函数签名定义的参数数量相同:

ON_CALL(*this, Addition(_,_))
                    //   ^^  Add an additional matcher
    .WillByDefault(Invoke(&real_, &CBasicMath::Addition));

// ...

MOCK_METHOD2(Addition, int(int x, int y));
                        // ^^^^^  ^^^^^ here you have 2 parameters need matching