name: lean-dev-flow
description: Lean implementation loop for mdeapp (SAN-NNN) tasks. Use this skill whenever starting implementation of any Linear issue, choosing which tests to run, setting up or cleaning up a worktree, or when mde-task-lifecycle phases 3–4 feel heavy for the change at hand. Provides: the 7-step loop (read→implement→T1 test→typecheck→commit→push→PR), test-tier selection by change shape (T1 targeted ~2s / T2 domain ~5s / T3 floor ~3min), worktree bootstrap/audit/clean commands, local-vs-CI verification matrix, and structured evidence capture. ALWAYS invoke this before running npm run floor locally, spinning up the dev server for a backend-only change, or doing a full-suite test run after a single-file edit. Replaces the "lint-per-chunk + build-per-chunk + floor-before-commit" pattern that burns 2–3min per task cycle with no safety benefit.
title: lean-dev-flow — mdeapp lean implementation loop
impact: HIGH
impactDescription: Cuts per-task cycle overhead by eliminating floor-on-every-change, wrong test tier, stale worktrees, and silent verify-script failures
tags: lean, mde-task-lifecycle, testing, worktree, vitest, verification, implementation, efficiency
paths:
- "mdeapp/src/**"
- "mdeapp/e2e/**"
- "mdeapp/scripts/**"
- "mdeapp/workspace/**"
lean-dev-flow
BLUF: Five minutes of per-task friction accumulates to hours lost per cycle. This skill makes the inner loop as fast as it can be without dropping safety — by running the right verification at the right time instead of running everything every time.
The 7-step lean loop
Every task, every time. No detours.
1. READ — Read only the files you will change + their existing test files
2. IMPLEMENT — Make the targeted change
3. T1 TEST — npm test -- --run src/path/to/file.test.ts (~2s)
4. TYPECHECK — npx tsc --noEmit (~5s, catches import drift)
5. COMMIT — git add <specific files> && git commit (never git add -A)
6. PUSH — git push
7. PR — gh pr create
CI runs lint + build + full test suite. You don't need to reproduce CI locally — you need to be confident before pushing, which targeted tests + typecheck achieves faster and more reliably than floor.
Test tier selection
Pick the lowest tier that proves the claim. Moving up a tier costs 2–3 extra minutes.
| Tier | Command | When | Time |
|---|
| T1 — Targeted | npm test -- --run src/path/to/file.test.ts | Single file changed | ~2s |
| T2 — Domain | npm test -- --run src/mastra/ (or src/lib/, src/hooks/) | Domain-wide impact (shared hook, Zod schema, concierge agent) | ~5s |
| T3 — Floor | npm run floor | PR open time — once, not per commit | ~3min |
Tier decision rules:
| Change | Tier |
|---|
| Added/edited a single test file | T1 (just that file) |
| Changed a utility used in one place | T1 |
| Changed a hook used by multiple components | T2 (src/hooks/) |
| Changed concierge Zod schema | T2 (src/mastra/) |
Changed a shared lib (src/lib/) | T2 |
| Changed a Next.js page or layout | T1 + Playwright smoke |
| PR ready to open | T3 — one run, then CI takes over |
| Docs/config only change | No test run needed |
Full decision tree with edge cases → references/test-tiers.md
Verification matrix — what runs where
Never reproduce what CI already owns.
| Check | Pre-commit | Pre-push | CI (floor.yml) | Before Done |
|---|
| T1 targeted vitest | ✅ | ✅ | — | — |
| T2 domain vitest | — | ✅ if domain touched | — | — |
tsc --noEmit | — | ✅ | ✅ | — |
| ESLint | — | — | ✅ | — |
next build | — | — | ✅ | — |
| Full vitest suite | — | — | ✅ | — |
npm audit | — | — | ✅ | — |
verify:console:boot | — | — | — | ✅ UI changes |
smoke:golden-queries | — | — | — | ✅ AI path changes |
| Playwright P0 smoke | — | — | — | ✅ user journey changes |
| Prod synthetic smoke | — | — | Nightly | Release |
Server-dependent verify scripts (verify:console, verify:grounding, verify:rental-pins, etc.) require localhost:3001. Before running any of them, confirm the server is alive:
curl -s -o /dev/null -w "%{http_code}" http://localhost:3001/
If not 200, restart with npm run dev:ui first, then wait for "Ready in".
Full matrix with rationale → references/verification-matrix.md
What to skip
Eliminating these patterns is the highest-ROI part of this skill.
| Pattern | Cost | Replace with |
|---|
npm run floor before every commit | 3min/commit; CI does this | T1 before commit, T3 at PR time only |
npm run lint per chunk during coding | ~30s/run; CI catches it | Skip locally; fix when CI flags |
npm run build for a lib/hook change | 90s for a type question | tsc --noEmit (5s) |
| Reading CLAUDE.md/sitemap.md every task | Context load waste | Read once; reference the specific section |
git status after every edit | Noise | Only before git add |
| Re-reading a file after editing | Edit tool confirmed success | Don't re-read |
| Starting dev server for backend-only change | 30s boot waste | Server needed only for UI/verify:* |
git add -A | Risks staging .env, WIP files | Always git add <specific files> |
| Running full E2E for a non-UI change | 3–8min; nothing to prove | Skip; Playwright is for user journeys |
Worktree bootstrap
Every branch gets an isolated worktree. Use workspace/wt-san-NNN-slug/ — never work in the main worktree on a feature branch.
bash mdeapp/scripts/wt-new.sh <SAN-NNN> <slug>
bash mdeapp/scripts/wt-audit.sh
bash mdeapp/scripts/wt-clean.sh --stale
Canonical worktree root: mdeapp/workspace/wt-san-NNN-slug/
If the scripts don't exist yet (check with ls mdeapp/scripts/wt-new.sh):
- Read references/worktree-ops.md for the full 20-line script bodies.
- Create them:
bash mdeapp/scripts/wt-new.sh takes ~2 min to write once.
- Until they exist, fall back to git directly:
git -C /home/sk/mdeai/mdeapp fetch origin main --quiet
git -C /home/sk/mdeai/mdeapp worktree add workspace/wt-san-NNN-slug -b ai/san-NNN-slug origin/main
Evidence capture
Before flipping any task to Done, capture runtime-verified evidence. "I reviewed the code" is not evidence.
For test-only changes:
npm test -- --run src/path/to/file.test.ts 2>&1 | grep -E "Tests|passed|failed"
For UI/server changes:
curl -s -o /dev/null -w "%{http_code}" http://localhost:3001/
npm run verify:console:boot
For API/agent path changes:
npm run smoke:golden-queries
Evidence format for task .md (append to ## Verification section):
## Evidence — SAN-NNN
- [x] Tests: N passed (`src/path/file.test.ts`, sha <abbrev>)
- [x] GET /: HTTP 200 @ localhost:3001
- [x] POST /api/copilotkit: HTTP 200
- [x] [relevant smoke output line]
Structured evidence script template → references/evidence-template.md
Recommended package.json additions
Add these to mdeapp/package.json scripts:
"check": "npm run typecheck && npm test -- --run",
"floor:fast": "concurrently --kill-others-on-fail 'npm run lint' 'npm run typecheck' 'npm test -- --run' && npm run build && npm run audit",
"test:mastra": "vitest run src/mastra/",
"test:lib": "vitest run src/lib/",
"test:hooks": "vitest run src/hooks/",
"test:api": "vitest run src/app/api/",
"test:e2e:smoke": "npm run test:e2e:p0-focused"
npm run check = typecheck + full test suite, no build (~15s). Default for 80% of changes.
npm run floor:fast = parallel lint+typecheck+tests, then serial build+audit (~45s vs ~3min sequential).
Integration with mde-task-lifecycle
This skill operates inside phases 3 and 4. The lifecycle owns everything else.
| Phase | mde-task-lifecycle owns | lean-dev-flow adds |
|---|
| Phase 3 — Implement | Entry criteria, wiring plan, read-before-edit rule | 7-step loop replaces lint-per-chunk + build-per-chunk |
| Phase 4 — Test | Which test types apply, failure triage, smoke steps | Tier selection (T1/T2/T3), local-vs-CI matrix |
| Phase 5 — Ship | Bookkeeping, changelog, PR | Structured evidence format before Done flip |
Routing
| Need | Route to |
|---|
| Full task lifecycle (plan → research → ship) | mde-task-lifecycle |
| Worktree/PR discipline and forensic cleanup | mde-worktree-pr-flow |
| Vitest patterns (mocks, fixtures, RTL) | vitest skill |
| Playwright setup, selectors, network mocking | playwright-cli skill |
| Pre-ship gate full checklist | /deploy-check |
| Debugging a failing test or build error | systematic-debugging |
| Supabase migration safety | mde-supabase |
