Tcr Kentbeck

TCR (Test && Commit || Revert)

Non-negotiables

When this skill applies, treat TCR as mandatory, not optional:

1. One small step — Prefer the smallest change that could move tests toward green (or add a failing test first in strict TDD, then minimal implementation).
2. Run tests — Use the project’s real test command (see [Detecting the test command](#detecting-the-test-command)). Always run the full suite for that command (same as CI / default project test entrypoint): e.g. pytest with no path arguments, npm test / pnpm test / yarn test, cargo test, go test ./..., make test if that runs everything. Do not narrow to a single file, class, or -k filter unless the user explicitly asks for a scoped run.
3. Green → commit — If tests pass, commit that step immediately with a message that describes what changed (present tense, imperative).
4. Red → revert — If tests fail, do not keep the change. Restore the working tree to the last committed state (git restore . / git checkout -- . or revert unstaged edits as appropriate). Then retry with a smaller or different step.

1. Red → log — After reverting, append an entry to tcr-failure-log.md at the repository root (create it with a short title if missing). Record what went wrong so the failure is not invisible: when (ISO timestamp or equivalent), which test(s) failed and the assertion or error (or a short traceback excerpt), what change was attempted (intent in one or two sentences), and optionally what to try next. This file is append-only; do not delete past entries. Commit this log update with the next green commit if it is part of the same work, or as its own tiny commit if the user prefers a clean separation.

Do not accumulate uncommitted red edits “to fix in the next message.” Red means revert first, then log.

Workflow loop

edit (tiny) → run tests → pass? → git add + git commit
                      ↘ fail? → revert working tree → append tcr-failure-log.md → try again

Git behavior

• Commit: Include only files that belong to the green step; keep commits small and atomic.
• Revert on failure: Prefer discarding uncommitted changes to return to last commit. Do not commit broken states. If a commit was already made by mistake while red, use the project’s agreed recovery (e.g. git reset --soft HEAD~1 only when the user expects rewriting history—default to revert/discard before committing).
• Branch: Same rules on feature branches: never push a sequence that leaves mainline patterns broken if your workflow requires linear green history.

Detecting the test command

Resolve how to test from the repo, in order:

1. package.json → scripts.test (or npm test / pnpm test / yarn test).
2. Makefile → make test or documented target.
3. pytest, cargo test, go test ./..., Maven/Gradle, etc., from project conventions.
4. If unclear, check README, CI config (e.g. .github/workflows), or ask once.

Use the same command the project already uses; do not invent a second test runner without reason.

Full suite: The goal is “everything this project’s standard test command runs.” If the repo documents a different “full” command (e.g. make test-all vs make test), use the one that matches CI or README for complete coverage.

Agent conduct

• Proactive: After substantive edits, run the full test suite before suggesting the task is done.
• Honest: If tests cannot be run in the environment, say so and either request permission to run them or describe exact commands for the user—do not claim TCR compliance without a green run.
• Scope: TCR applies to coding tasks that touch behavior covered by tests; pure docs-only changes may skip tests only when they cannot affect execution.

Optional: user escape hatch

If the user explicitly says to skip TCR or bend the workflow for a one-off (e.g. WIP checkpoint), follow their instruction for that turn only, then return to TCR unless they say otherwise.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: xpepper
• Source: xpepper/tcr-skill
• License: MIT

Install and usage instructions live in the source repository linked above.