I’ve been working in C++ for a few months now – after three years we’ve been apart.
I always amazes me how simple things I took for granted do not exist (at least not out of the box) in C++, one of which are reflection.
Two weeks ago I needed to make sure that a method was called in a test, I could have used Google’s mocking framework but I needed simpler and quicker solution. I just wanted to know in a specific point at the test if a method was called.
Although C++ does not have reflection it does have macros (i.e. #Define) and I’ve utilized the C++ macros to create the following class:
void AddMethodCall(std::string methodName)
bool WasCalled(std::string methodName)
return _methodsCalled.count(methodName) > 0;
#define REGISTER_METHOD(METHODNAME) \
void METHODNAME () override\
bool METHODNAME##WasCalled() \
return WasCalled(#METHODNAME); \
By inheriting from the class above I could define the “mocked” methods, each method would have another method auto-generated so I can test if the method was called.
class MyClassMock : public MyClass, public TestListenerBase
Using this solution I needed to declare each method, the good news is that renaming the method would cause the mocked method name to change as well.
Using the new "mock object" is a simple as writing code:
int _tmain(int argc, _TCHAR* argv)
bool result = mock.DoSomethingWasCalled(); // return false
result = mock.DoSomethingWasCalled(); // result true
That’s it – it’s not perfect but it works.
In case you like parameters in your method you’ll have to improve this example – it’s not hard and I know you’re up to the task.
Labels: C++, Mock objects