How do I use Google Mock for unit testing in C++?

How do I use Google Mock for unit testing in C++?

Google Mock is a framework that allows you to create mock objects for testing. First, you need to include the necessary headers and link against the Google Mock library.

Can you give me a simple example of creating a mock class?

Sure! Here's a basic example:

#include <gmock/gmock.h>

class MyInterface {
public:
    virtual int DoSomething(int x) = 0;
};

class MockMyInterface : public MyInterface {
public:
    MOCK_METHOD(int, DoSomething, (int x), (override));
};

This creates a mock class MockMyInterface that can be used in your tests.

How do I set expectations on the mock object?

You can set expectations using the EXPECT_CALL macro. For example:

MockMyInterface mock;
EXPECT_CALL(mock, DoSomething(5)).WillOnce(Return(10));

This sets an expectation that DoSomething(5) will be called and will return 10.

What if the expectation is not met?

If the expectation is not met, Google Mock will report a failure when you run your tests, indicating which expectations were not satisfied.