Motivation
Watch mode currently reruns the discovered test set after changes. As projects grow, rerunning unaffected tests makes the feedback loop slow.
Proposed work
- Track source and test file changes between runs.
- Immediately rerun a changed test file.
- Add a dependency strategy for mapping changed source files to affected tests.
- Fall back safely to the full suite when dependency information is unavailable.
- Preserve debounce behavior and expose why each test was selected.
Acceptance criteria
- Editing one test file reruns only that file by default.
- Source changes use documented affected-test behavior.
- Deletes, renames, and newly added tests are handled.
- A full-rerun command remains available in watch mode.