kesyog/cpputest_mockify

Stupid simple CppUTest/CppUMock mock generation

CppUTest mockify

Easily generate mocks to be used with the CppUTest mocking framework. lowering the barrier to writing C unit tests. Interested in how this can help you? Check out this great post from the guys at Memfault.

Usage

To generate a .cpp mock file, run:

cpputest_mockify.py <input_file.h> <output directory>

Afterward, scan the output file for instances of FIXME, CHECKME, or WRITEME, indicating areas where manual intervention is required.

Benefits

• Stupid simple to use
• No external dependencies
• No need to configure include paths or otherwise tell it anything about your build
• Compatible with Python 2 and 3

Drawbacks

In the end, the script boils down to a surprisingly-effective but very hacky regex 🤷

To keep usage (and the implementation) simple, it doesn't use a real C language parser (e.g. pycparser) so it's not to going to work reliably 100% of the time. For example, array parameters aren't really handled well. In practice, on real code™, it will get you ~80-90% of the way there and let you know when it needs further help.

The script doesn't currently do incremental mock generation. If you add a new function to your header file, you're best off overwriting your old mock and relying on version control to manage the changes.

Other contributors

Thanks to Noah Pendleton and Alan Rosenthal for cleaning up my hacks and adding functionality. Also to https://github.com/marco-m/mockify, the original inspiration for the script.

Alternatives

• https://github.com/marco-m/mockify: uses pycparser to get a deeper understanding of your code.
• https://github.com/jgonzalezdr/CppUMockGen

cpputest_mockify's Issues

Run clang-format on the output

I had to remove a change from @noahp to run clang-format on the output. For some reason, the subprocess call was hanging. Need to dig into it more.

Add testing and CI

Add some test vectors and run against different Python versions