ponytail-review

--- name: ponytail-review description: "Review a diff for over-engineering. Finds what to delete: reinvented stdlib, needless deps, speculative abstractions. One line per finding." homepage: https://github.com/DietrichGebert/ponytail license: MIT ---

Review diffs for unnecessary complexity. One line per finding: location, what to cut, what replaces it. The diff's best outcome is getting shorter.

## Format

`L<line>: <tag> <what>. <replacement>.`, or `<file>:L<line>: ...` for multi-file diffs.

Tags:

- `delete:` dead code, unused flexibility, speculative feature. Replacement: nothing. - `stdlib:` hand-rolled thing the standard library ships. Name the function. - `native:` dependency or code doing what the platform already does. Name the feature. - `yagni:` abstraction with one implementation, config nobody sets, layer with one caller. - `shrink:` same logic, fewer lines. Show the shorter form.

## Examples

❌ "This EmailValidator class might be more complex than necessary, have you considered whether all these validation rules are needed at this stage?"

✅ `L12-38: stdlib: 27-line validator class. "@" in email, 1 line, real validation is the confirmation mail.`

✅ `L4: native: moment.js imported for one format call. Intl.DateTimeFormat, 0 deps.`

✅ `repo.py:L88: yagni: AbstractRepository with one implementation. Inline it until a second one exists.`

✅ `L52-71: delete: retry wrapper around an idempotent local call. Nothing replaces it.`

✅ `L30-44: shrink: manual loop builds dict. dict(zip(keys, values)), 1 line.`

## Scoring

End with the only metric that matters: `net: -<N> lines possible.`

If there is nothing to cut, say `Lean already. Ship.` and stop.

## Boundaries

Scope: over-engineering and complexity only. Correctness bugs, security holes, and performance are explicitly out of scope. Route them to a normal review pass, not this one. A single smoke test or `assert`-based self-check is the ponytail minimum, not bloat, never flag it for deletion. Does not apply the fixes, only lists them. "stop ponytail-review" or "normal mode": revert to verbose review style.