How can you use utility functions with UnitTest++

Question

I'm using UnitTest++ for unit testing C++ code.

In my tests, there's a group of tests I repeat several times. What I'd like is for a utility function to perform these tests. In short, I'd like to take this:

TEST( foo ) {
    Foo one;
    Foo two;

    // init one & two
    // lots of CHECK_CLOSE(one.bar, two.bar, 1e-5); in repeating cycles
}

TEST( bar ) {
    Foo one;
    Foo two;

    // init one & two
    // lots of CHECK_CLOSE(one.bar, two.bar, 1e-5); in repeating cycles
}

And use this:

void blah( const Foo& one, const Foo& two ) {
    // lots of CHECK_CLOSE(one.bar, two.bar, 1e-5);
}

TEST( foo ) {
    Foo one;
    Foo two;

    // init one & two
    blah(one, two);
}

TEST( bar ) {
    Foo one;
    Foo two;

    // init one & two
    blah(one, two);
}

This doesn't work due to UnitTest++'s macro manipulations. What is the best way to approach this problem?

edit: A couple of thoughts which I can't check out right now.

1. If I use a fixture, with the utility function in the struct, will I be able to call UnitTest++ macros from within this function?
2. I can write a macro to perform the common tests. I don't really like this, but at least I'll stary dry...

Answer 1

I would recommend against doing this, because what happens is you lose a lot of information about which test had failed, the wrapper function now encloses the functionality of two or more tests, so when it fails you have to trace back to see what was the reason for the failing test.

Answer 2

Make your common check function to return bool. And then CHECK or ASSERT result of your common function in each TEST.

Answer 3

Write a macro to do it. Don't let the "macros are evil" mantra hide this fact from you: Macros are designed to generate repetitive code.