lang-typescriptlisted

# Skill: Language — TypeScript > **Load trigger:** `"load lang-typescript skill"` > **Stack:** TypeScript, Node.js, ESLint, tsc, Jest/Vitest, npm > **Token cost:** Low ## Toolchain Reference | Gate | Tool | Command | Config file | | --------- | ----------------- | ----------------------- | -------------------------------------- | | Lint | ESLint | `npm run lint` | `.eslintrc.js` or `eslint.config.js` | | Typecheck | tsc | `npm run typecheck` | `tsconfig.json` | | Test | Jest or Vitest | `npm run test` | `jest.config.ts` or `vitest.config.ts` | | Coverage | Jest `--coverage` | `npm run test:coverage` | `jest.config.ts` | | Preflight | custom | `npm run preflight` | `scripts/preflight.sh` | ## File Layout Convention ``` src/ types/index.ts ← all shared types and interfaces services/ ← business logic, no UI dependencies utils/ ← pure functions, no side effects screens/ or pages/ ← UI layer only tests/ services/ ← mirrors src/services/ utils/ ← mirrors src/utils/ ``` ## CI Gate Commands (ci-quality.yml) ```yaml - name: Lint run: npm ci && npm run lint - name: Typecheck run: npm run typecheck - name: Test with coverage run: npm run test:coverage env: CI: true - name: Coverage threshold