Ensure all code changes include appropriate unit tests and address any identified testing gaps immediately. When reviewing code, verify that: 1. **New functionality has corresponding tests**: Every new feature or significant code change should include unit tests that exercise the new behavior. 2. **Existing untested code gets tests when modified**: If you're working on code that lacks test coverage, add tests as part of your changes rather than deferring them. 3. **Test TODOs are addressed, not accumulated**: Don't leave comments like "TODO: This has a bug!!!" in test code. Either fix the issue immediately or create a proper ticket to track it. 4. **Mark missing test areas explicitly**: When you identify code that needs tests but can't add them immediately, add clear TODO comments like `(* TODO: test this *)` to acknowledge the gap and help future developers. Example from the discussions: ```ocaml (* Instead of leaving this unaddressed: *) (* TODO: This has a bug!!! Suppose we exclude `test.py` and are given `tests2/test.py`. This code will not exclude properly... *) (* Do this: *) (* Add unit test for path exclusion edge cases - see issue #1234 *) let test_path_exclusion_with_nested_dirs () = (* Test the specific bug case mentioned *) assert (excludes_file "test.py" "tests2/test.py" = true) ``` The goal is to build confidence in code changes through comprehensive testing rather than relying on manual verification like "run -cfg_il and looks like it's ok".