inheritance and TestWithParam

[Joey]

Most of my test cases are now data-driven with TestWithParam. I use an
array-of-structures where each structure describes one interesting
combination of values. Like it says in the FAQ this approach has lots
of advantages over using subroutines.

The catch is that I end up testing one logical grouping need several
test fixtures that vary only in parameter datatype like:

class FixtureA : public ::testing::TestWithParam<struct_A_t>;
class FixtureB : public ::testing::TestWithParam<struct_B_t>;
class FixtureWithoutParametersC : public ::testing::Test;

Where A might iterate across several baudrates, while B is going to
vary in some different way, and C contains tests that need no
parameter. But they still have some pieces in common.
With ::testing::Test this is easy to express because you can can use
one fixture or subclass and create several fixtures.

What about for TestWithParam? For now I just do as above which results
in some code duplication and pushes me toward using more globals.
Multiple inheritance might work instead. What do you think?

[Vlad Losev]

Hi Joey,

My advice would be to factor out all the common stuff into a separate class and then instantiate and access it in your fixture classes. But you should be able to do it with mixins, as well. It can also be done using a templated base class, although that makes your code - and compiler errors it produces - harder to understand.

- Vlad