# CLAUDE.md

**Do not edit this file.** Agents must never add, remove, or reword anything here. If a change seems needed, say so and let a human do it.

## Ask before testing

When asked to review code or build a feature, do not run the test suite and do not write new tests. Make the change, report it, then ask the user whether tests should be added — describing the tests you have in mind — and wait for the user to confirm.

Two reasons this matters here: the suite takes minutes, and `tests/.snapshots/success.txt` plus the tally in `tests/Visual/Parallel.php` encode the whole suite's result, so a single added test breaks both.

Once the user confirms:

```bash
composer test:unit         # fast, excludes the visual group
composer test:integration  # visual and snapshot tests
composer test              # everything CI runs, in CI's order
composer update:snapshots  # only when a test was added or removed
```

## TIA scenario tests

`tests/Features/Tia/*` scaffold a throwaway git project, run a real `pest` subprocess against it, and diff the TIA graph it wrote. They exist because TIA's contract is about what a run *writes* — replay, branch keys, and the COMPLETE / RESULTS-ONLY / HARD-SUPPRESSED tiers are invisible to ordinary assertions, and every case used to be measured by hand against a playground app.

Add one whenever a change touches branch resolution, replay, filtered mode, or the write tiers. How:

- `Project::make('master')` scaffolds; `seed('master')` writes a graph and sentinels every cached result (`time=9.999`, `assertions=42`) so any rewrite shows up.
- `$project->pest('--tia', …)` runs it; `$project->delta()` compares against that snapshot. `writtenCount()` is the discriminator — `0` means "replayed", not "wrote the same values". `mutateGraph()` bends one entry; overlays in `tests/Fixtures/Tia/overlays/<name>/` supply a different `tests/Pest.php`.
- Keep expectations driver-independent: a cold recording run needs pcov/xdebug and behaves differently without one. Seed a graph instead of recording one.

Run them by file (a directory argument finds nothing) or by `--filter`:

```bash
php bin/pest tests/Features/Tia/PartialRunWriteTier.php
```
