testy test framework (?)

This is a real bad c test framework that has 1 possibly redeeming quality:

1. define your test functions in line with the function under test!

Example:

#include "testy.h"

int multiply(int a, int b) {
    return a * b;
}

// test the above multiply function
TEST(multiply, {
    assert(multiply(2, 3) == 6);
}
)

Found the idea in this nice writeup, see link below or testy.h.

https://blog.noctua-software.com/c-unit-tests-constructor-attribute.html

Usage

1. Copy testy.c + testy.h + testy.py into your project
2. Implement some tests (see example/example.c for an example). You may need to include mocks.
3. Run ./testy.py passing your c file as argument.

Note on mocks

To limit the amount of effort spent mocking, I'm using a wonderful idea from here:

https://github.com/jwgrenning/gen-xfakes

I capture linker output and produce a stub for any missing definitions containing a single assert(0). If any of the generated stubs are executed during a test, it will crash/fail, and a proper mock will need to be included in a TEST() statement (see example/example.c for an example).

Note on main

The testy main function is named __wrap_main to take advantage of the ld --wrap argument; this allows me to substitute the testy main in place of any potential real main function in the file under test (it also works correctly if there's no __real_main function present).

TODO

• support injecting more compiler flags (it might make more sense to hook into the normal project's build command, like how scan-build operates, and get all the c files and compiler flags from there)
• run in parallel + output summary? (can be done via gnu parallel as-is 😬)
• build caching (eg via Make?)?
• 🌈 colors 🌈 ?
• coverage (gcov)