Testability

Philosophy

Code that's hard to test is telling you something about its design. Coverage gaps are opportunities to improve architecture, not problems to silence.

Fix the design, don't silence the messenger.

Refactoring Patterns

1. Extract Pure Logic from I/O

// BEFORE: Hard to test
res_t process_config(const char *path) {
    char *content = read_file(path);
    // ... parsing logic ...
}