On 16.12.2024 at 14:18, Jakub Zelenka wrote: > I have been looking into how to test some cases where integration tests are > very difficult or even impossible to create for. Those are often found in > networking related and system specific code code (network.c, streams, FPM > and more). I was recently fixing one such bug and decided to give a try > which resulted in this PR: https://github.com/php/php-src/pull/16987 .
It makes sense to me to have some unit tests for code which is otherwise hard or even impossible to test via integration tests. > There was a suggestion of RFC but that might be a bit too much as it's just > an internal change / addition. But certainly some overview on internals > should be done so writing this instead. I'm fine with not going through the RFC process, although the policy[1] police might come after us. :) > I decided to use cmocka in that PR because I had some experience with that. > It's quite small and still very powerful and allow vast mocking options. > It's a bit manual but it gives a bigger control over the mock. It relies on > --wrap linking option that replaces original functions with wraps. This is > however available only on Linux (or maybe some other Unix variants) but > doesn't work on MacOS or Windows. The developers that want to use it on > those platforms would need to use some Linux Virtualisation option (e.g. > Docker). Especially on Windows, where we have different code paths, and sometimes even completely different code, it would be great to also have these unit tests. Given that link.exe supports /alternatename, a bit of additional macro magic might do the trick[2]. I'll try to have a stab at this soon. > I did also some research into the other mocking libraries in C. Thank you! I barely have any experience with unit testing in C (only one time, long ago, wrote part of unit test for timelib which is using Cpputest), but from a cursory glance cmocka appears to be suitable for our purposes. > In terms of CI. It has got its own build which is very simple and it tests > just specific parts so we could just limit it to run only for changed files > which might be quite convenient. If the tests won't take long, in my opinion we could run them for every push. Or at least in nightly (plus when relevant files changed), to avoid that the suite doesn't run for a long time (possibly weeks), and then suddenly is broken for external reasons. [1] <https://github.com/php/policies/blob/main/third-party-code.rst> [2] <https://stackoverflow.com/questions/33790425/visual-studio-c-linker-wrap-option> Christoph
