Question

This is a revised/better written version of the question I asked earlier today — that question is deleted now.

I have a project where I’m getting started with Google Mock. I have created a class, and that class calls functions whithin the Windows API. I’ve also created a wrapper class with virtual functions wrapping the Windows API, as described in the Google Mock CheatSheet. I’m confused however at how I should pass the wrapper into my class that uses that object. Obviously that object needs to be polymorphic, so I can’t pass it by value, forcing me to pass a pointer. That in and of itself is not a problem, but I’m confused as to who should own the pointer to the class wrapping the API.

So… how should I pass the wrapper class into the real class to facilitate mocking?

Here’s an example of what I mean:

struct A {
    virtual void SomeMethod(int x, int y)
    {
        ::SomeMethod(x, y);
    };
};

class Client
{
    A * method_;
public:
    Client(A * method = new A) : method_(method) {};
    void DoSomething()
    {
        method_->SomeMethod(42, 34);
    }
};

struct Mock : public A
{
    MOCK_METHOD2(SomeMethod, void(int, int));
};

TEST(MyTest, MyTestWithMock)
{
    Mock * mock = new Mock();
    EXPECT_CALL(*mock, SomeMethod(42, 34)).Times(1);
    Client client(mock); //Should *client* be responsable for deleting mock?
    client.DoSomething();
};

EXAMPLE 2:

struct A {
    virtual void SomeMethod(int x, int y)
    {
        ::SomeMethod(x, y);
    };
};

class Client
{
    A * method_;
public:
    Client(A * method) : method_(method) {};
    static Client Create()
    {
        static A;
        return Client(&A);
    }
    void DoSomething()
    {
        method_->SomeMethod(42, 34);
    }
};

struct Mock : public A
{
    MOCK_METHOD2(SomeMethod, void(int, int));
};

TEST(MyTest, MyTestWithMock)
{
    Mock  mock;
    EXPECT_CALL(mock, SomeMethod(42, 34)).Times(1);
    Client client(&mock);
    client.DoSomething();
};

Answer 1

There’s always the option of using shared_ptr; that would certainly solve the ownership problem.