Implement
End-to-end feature implementation pipeline. Runs pre-flight validation, TDD cycle, scope enforcement, and quality commit as a single orchestrated flow.
Do NOT load this skill when the user only wants a focused subflow like /tdd or /quality-commit, or when the work is already finished and only needs verification or commit handling.
NEVER
- Never skip pre-flight — writing code on a broken baseline wastes the whole TDD cycle.
- Never add features not covered by tests during the Green phase — that's scope creep inside a test cycle.
- Never use
git add -Aorgit add.— stage specific files only. - Never proceed past bootstrap mock failure — it means your mock wiring is broken, not a Red/Green issue.
- Never commit with pre-existing lint errors in files you didn't touch — note them in the commit message instead.
- Never treat a passing test during Red as "good enough" — a test that passes before implementation isn't testing new behavior.
Abort Conditions
STOP the pipeline and ask the user if:
- Pre-flight finds the workspace in a broken state (typecheck fails before your changes)
- More than 5 files need modification (scope may be too large for one commit)
- Bootstrap mock test fails after 2 attempts
- Full suite regression caused by your changes
Decision Tree: Which Phase to Start From
Is the workspace clean and green?
├── No → Pre-flight: fix or ask before any code
└── Yes → Proceed
Does a test file already exist for the target module?
├── Yes → Run it first; confirm green baseline
└── No → Bootstrap mock is your first step
Does the task touch > 5 files?
├── Yes → Ask user to confirm scope before writing
└── No → ProceedPipeline
Phase 0: Pre-flight (< 30 seconds)
git status --short
npx tsc --noEmit 2>&1 | head -20If monorepo: check if shared/library packages need rebuild (source newer than compiled output).
If any check fails: report and ask how to proceed before writing code.
Phase 1: Understand & Plan
Read target files. Identify module type (route handler, repository, plugin, utility, service, component). Check nearest test files for established mock patterns.
Brief summary: "I'll add X tests covering Y, then implement Z." Wait for confirmation if scope > 3 files.
Phase 2: Bootstrap Mock (1 test)
Write ONE minimal test that imports the module and verifies mocks resolve. Run it — must pass.
If it fails after 2 attempts: STOP. Mock wiring is broken (wrong module path, incorrect mock factory, missing type shim). Fix that before Red/Green.
Phase 3: Red — Write Failing Tests
Write tests for: happy path, edge cases, error cases.
Run the file — ALL new tests MUST fail. If any pass unexpectedly, the tests aren't testing new behavior.
Phase 4: Green — Minimum Implementation
Write the minimum code to make all tests pass. Then run — all tests MUST pass.
Do NOT add features not covered by tests. Do NOT optimize. Do NOT refactor existing code.
Phase 5: Scope Guard
git diff --name-onlyFlag files that don't relate to the task:
- Formatting-only changes → revert with
git checkout -- <file> - Unrelated refactors → revert or split into separate commit
- Docstring additions to untouched code → revert
Phase 6: Full Suite + Quality Gates
npx vitest run --reporter=dot
npx tsc --noEmit
npx eslint <changed files only>Triage failures:
- Test failure in your files → regression, fix it
- Type error → fix it
- Lint in your files → fix it
- Lint in files you didn't touch → note in commit message, do not fix
Phase 7: Commit
git add <specific files>
git commit -m "type(scope): description
Co-Authored-By: Claude <noreply@anthropic.com>"Arguments
$ARGUMENTS: What to implement
- Example: /implement add rate limiting to POST /api/search - Example: /implement src/routes/admin/settings.ts — add PATCH endpoint for theme - If empty: ask the user what to implement