Can a mock class inherit from another mock class in googlemock?

Can a mock class inherit from another mock class in googlemock? If yes, then please help me in understanding why isn't this working.

class IA
{
public:
   virtual in开发者_如何学Pythont test1(int a) = 0;
};

class IB : public IA
{
public:
   virtual float test2(float b) = 0;
};

class MockA : public IA
{
public:
   MOCK_METHOD1(test1, int (int a));
};

class MockB : public MockA, public IB
{
public:
   MOCK_METHOD1(test2, float (float b));
};

I get a cannot instantiate abstract class compiler error for MockB but not for MockA

If you plan on using multiple inheritance, you should be using virtual inheritance.

Next example compiles and link fine :

class IA
{
    public:
        virtual int test1(int a) = 0;
};

class IB : virtual public IA
{
    public:
        virtual float test2(float b) = 0;
};

class MockA :virtual public IA
{
    public:
        int test1(int a)
        {
            return a+1;
        }
};

class MockB : public MockA, public IB
{
    public:
        float test2(float b)
        {
            return b+0.1;
        }
};

int main()
{
    MockB b;
    (void)b;
}

It is just a small modification of your example

Class MockB inherits from IB which has two purely abstract functions: test1 and test2. And you need to override both of them. Inheriting from MockA which overrides test1 is insufficient (at lest in C++ - in Java it would work). So the fix is to add

virtual int test1(int a)
{
    return MockA::test1(a);
}

to MockB definition.