Lands L3 of the agent-first coverage architecture (ADR-020) — the
mutation-testing layer. Stryker on entities + use-cases (the pure
business-logic surface) catches the third dimension of test quality:
tests that exist + execute the code but assert nothing.
Deps (root devDependencies):
- @stryker-mutator/core ^8.7.0
- @stryker-mutator/vitest-runner ^8.7.0
Shared base: packages/core-testing/stryker.base.json
- testRunner: vitest (uses each feature's vitest.config.ts)
- mutate: src/entities/** + src/application/use-cases/** (excludes
tests, factories, contracts)
- thresholds: high 90 / low 80 / break 80
- reporters: progress + html + json (reports/mutation/{index.html,
mutation.json})
- incremental mode enabled, concurrency 4, timeout 10s
- exposed via @repo/core-testing/stryker.base.json subpath export
Per-feature config: packages/auth/stryker.config.json
- 4-line file that extends the shared base
- Proof-of-concept; other features get a config when L0 unification
closes their existing test gaps
Driver: scripts/coverage/mutate.mjs (zero-dep Node ESM)
- discoverStrykerConfigs: walks packages/* and apps/* for
stryker.config.json
- Supports --filter <name>, --since <ref> (incremental), --json
- Runs Stryker per-feature via node_modules/.bin/stryker run
- Surfaces per-package pass/fail summary; exits 1 on any failure
- Tests: scripts/coverage/mutate.test.mjs (3 tests, all green)
CI: .github/workflows/mutation-nightly.yml
- Cron at 02:30 UTC + workflow_dispatch with filter input
- Uploads reports/mutation/** as artifact (30-day retention)
- On failure, opens a tracking issue labelled mutation-testing
- permissions: contents: read, issues: write
- 60-min timeout (Stryker is slow by design)
Generator: turbo gen feature now scaffolds stryker.config.json from
turbo/generators/templates/feature/stryker.config.json.hbs — new
features ship mutation-ready out of the box.
Guide: docs/guides/coverage.md L3 section fleshed out with run
syntax, config shape, base config inventory, CI behavior, and a
"what you're looking for" primer on mutation scores.
Lockfile churn: pnpm regenerated the lockfile for the new deps;
~5K-line net reduction is collateral (pnpm version drift) but
mechanical.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Clean Architecture Monorepo Template
Turborepo + pnpm monorepo organised by vertical features, with an agent-first workflow and five conformance gates.
This template is built for agent-driven development. Sandcastle is the orchestration substrate; pnpm work dispatch is the entry point. See ADR-019 for the decision rationale and docs/guides/runbook.md for end-to-end usage.
Start here
Read docs/guides/runbook.md — day-1 onboarding (prerequisites, env vars, daily commands, troubleshooting, Using Sandcastle for agent dispatch).
Quick reference
pnpm install # Install + auto-wire husky pre-commit hooks
pnpm dev # All dev servers (web-next:3000, cms:3001, web-tanstack:3002, storybook:6006)
pnpm test # All tests
pnpm typecheck # TypeScript across all packages
pnpm lint # ESLint (incl. 8 conformance/* rules)
pnpm conformance # Cross-feature event closure
pnpm fallow # Whole-codebase: dead exports, dupes, complexity
pnpm turbo boundaries # Workspace dependency graph
pnpm work status # docs/work/ epic + story state
docker compose up -d # Start PostgreSQL
Documentation map
docs/guides/runbook.md— start hereCLAUDE.md— full conventions referenceAGENTS.md— package map + boundary rulesdocs/guides/conformance-quickref.md— manifest + 5-gate daily referencedocs/architecture/agent-first-workflow-and-conformance.md— full designdocs/architecture/feature-conformance-explainer.html— interactive explainer
Scaffolding
pnpm turbo gen feature <name> # Scaffold a feature (manifest + contracts + tests)
pnpm turbo gen event # Event contract or handler (requires gen core-package events)
pnpm turbo gen job # Background job
pnpm turbo gen realtime # Realtime channel (requires gen core-package realtime)
pnpm turbo gen core-package <name> # Optional core: events / realtime / trpc / ui / audit
pnpm turbo gen core-ui-component <name> # Atomic-design component
Generator-first is non-negotiable — hand-rolled feature/event/job/realtime/component code is rejected by reviewer agents and may fail the CI scaffold-drift check.
Optional packages
Five core packages scaffold on demand:
pnpm turbo gen core-package realtime # Socket.IO realtime layer (ADR-016)
pnpm turbo gen core-package events # Cross-feature events + Payload jobs (ADR-015)
pnpm turbo gen core-package trpc # tRPC server setup
pnpm turbo gen core-package ui # Design system
pnpm turbo gen core-package audit # DPA-compliant audit logging (ADR-018)
See docs/architecture/template-tiers.md for the full tier list.
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