How do you run your unit tests? Compiler flags? Static libraries?

Question

I\'m just getting started with TDD and am curious as to what approaches others take to run their tests. For reference, I am using the google testing framework, but I believe the

Answer 1

I go with #1, some reasons are

• It allows to check that each lib links correctly
• You don't want extra code in the product
• It's easier to debug individual small test programs
• You may need multiple executables for some tests (like communication tests)

For C++ build and test, I like to use CMake which can run a selection of the target executables as tests and print a summary of the results.

Answer 2

I'm using a third-party test-runners with their framework and including testing in build script. Tests are outside of production code (external dll).

Answer 3

For C/C++ apps I try to have as much code as possible in one or more dlls, with the main application being the bare minimum to start-up and hand-off to the dll. Dlls are much easier to test because they can export as many entry points as I like for a test application to use.

I use a seperate test application that links to the Dll(s). I'm strongly in favour of keeping test code and "product" code in seperate modules.

Answer 4

I tend to favour static libs over dlls so most of my C++ code ends up in static libs anyway and, as you've found, they're as easy to test as dlls.

For code that builds into an exe I either have a separate test project which simply includes the source files that are under test and that are usually built into the exe OR I build a new static lib that contains most of the exe and test that in the same way that I test all of my other static libs. I find that I usually take the 'most code in a library' approach with new projects and the 'pull the source files from the exe project into the test project' approach when I'm retro fitting tests to existing applications.

I don't like your options 2 and 3 at all. Managing the build configurations for 2 is probably harder than having a separate test project that simply pulls in the sources it needs and including all of the tests into the exe as you suggest in 3 is just wrong ;)

Answer 5

I use two approaches, for dlls I just link my unit tests with the dll, easy. For executables I include the source files that are being tested in both the executable project and the unit test project. This adds slightly to the build time but means I don't need to separate the executable in to a static lib and a main function.

I use boost.test for unit testing and cmake to generate my project files and I find this the easiest approach. Also I am slowly introducing unit-testing to a large legacy code base so I am trying to introduce the least amount of changes, in case I inconvenience other developers and discourage them from unit testing. I would worry that using a static library just for unit testing might be seen as an excuse not adopt it.

Having said this, I think the static library approach is a nice one especially if you are starting from scratch.

Answer 6

Personnally, I use another approach that relies a bit on yours:

I keep the project-to-test intact. If it's an executable, it should stay an executable. You simply create a post build action in order to aggregate all obj files into a static library.

Then, you can create you test project, linking the test framework and your previously generated static library.

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