在同一类的另一个方法中调用 C++ GoogleMock 模拟方法

Question

我在这里看这个问题: Can googlemock mock method calls from within other method calls of the same class?

并尝试实现答案，但它对我不起作用。

我已经修改了链接问题的实现以删除模拟 ReturnInputPlus1() ，这是接受的答案所建议的:

using ::testing::Invoke;
using ::testing::_;
using ::testing::Return;

class MyClass
{
  public:
    MyClass() : x(1) {}
    virtual ~MyClass() {}

    int ReturnInput(int x) { return x; }
    int ReturnInputPlus1(int x) { return ReturnInput(x) + 1; }
  private:
    int x;
};

class MockMyClass : public MyClass
{
public:
    MockMyClass()
    {
        ON_CALL(*this, ReturnInput(_)).WillByDefault(Invoke(&real, &MyClass::ReturnInput));
    }
    virtual ~MockMyClass() {}

    MOCK_METHOD1(ReturnInput, int(int y));

private:
    MyClass real;
};

TEST(MyClassTest, mockUseClassMethod)
{
    MockMyClass mock;

    EXPECT_CALL(mock, ReturnInput(_))
        .WillOnce(Return(2));

    EXPECT_EQ(3, mock.ReturnInputPlus1(1));
}

这仍然返回相同的失败

/projects/tests/cpp/google-test/test.cpp:46: Failure
      Expected: 3
To be equal to: mock.ReturnInputPlus1(1)
      Which is: 2
/projects/tests/cpp/google-test/test.cpp:41: Failure
Actual function call count doesn't match EXPECT_CALL(mock, ReturnInput(_))...
         Expected: to be called once
           Actual: never called - unsatisfied and active

Answer 1

如果不在 MyClass 中创建方法，我看不到一种方法可以实现对模拟行为的内部调用的重定向 virtual .

下面是一个工作示例:

• 删除了real 成员，mock 仍然继承了 MyClass
• 我想“技巧”是知道可以像这样调用父类行为:mock.MyClass::ReturnInputPlus1(1) ( qualified name lookup ) 并理解 dynamic dispatch将导致使用 M​​ockMyClass::ReturnInput。
• 我不太确定 MyClass::x 想要实现什么，因为它会被函数参数遮蔽。

---

class MyClass
{
public:
    MyClass()
        : m_x(1)
    {
    }
    virtual ~MyClass() {}

    virtual int ReturnInput(int x) { return x; }
    virtual int ReturnInputPlus1(int x) { return ReturnInput(x) + 1; }

private:
    int m_x;
};

class MockMyClass : public MyClass
{
public:
    MockMyClass()
        : MyClass()
    {
        ON_CALL(*this, ReturnInput(_)).WillByDefault(Invoke(this, &MyClass::ReturnInput));
    }
    virtual ~MockMyClass() {}

    MOCK_METHOD1(ReturnInput, int(int y));
    MOCK_METHOD1(ReturnInputPlus1, int(int y));
};

TEST(MyClassTest, mockUseClassMethod)
{
    MockMyClass mock;

    EXPECT_CALL(mock, ReturnInput(_)).WillOnce(Return(2));

    EXPECT_EQ(3, mock.MyClass::ReturnInputPlus1(1));
}