Hippomocks pointer argument - provide input, check output

Question

I have a function that expects a buffer length input in a pointer argument, and then puts the number of the read bytes into that same argument as output. Now in my unit test I try to mock it with Hippomocks, and would like to check if the function was called with the correct input value, and at the same time, provide a different output value. How could I achieve this? Thanks!

Answer 1

Picking in my memory since I haven't used Hippomocks in a long time, I can't give the exact syntax, but that's what Hippomocks' Do() method is for.

In Hippomocks' test suite you can find a usage example with a lambda expression: https://github.com/dascandy/hippomocks/blob/master/HippoMocksTest/test_do.cpp#L20.

Answer 2

You can do it for the function

void addingFunc(const int* inputArg_p, int* returnArg_p)
{
    *returnArg_p = *inputArg_p +1;
}

with

const int expected = 42;
int readbackActual = 0;
int readbackActual_p = &readbackActual;
const int writeValue = 1;
const int* writeValue_p = writeValue;

mocks.ExpectFuncCall(someFunc).With(Out(writeValue_p), In(readbackActual_p ); //Writes writeValue into *inputArg_p, then writes *returnArg_p into *readbackActual_p.

funcUnderTest(); //Function which uses addingFunc somehow.

ASSERT("FooBarError", expected == readbackActual); //Will fail: 42 is unequal to 1+1  !

(These unpretty pointers are used because Hippomocks complains about types when using &readbackActual directly.)