TypeScript Tooling

Priority: P1 (HIGH)

Implementation Guidelines

• Compiler: Use tsc for CI builds; esbuild or ts-node for development.
• Linting: Enforce ESLint with @typescript-eslint/recommended. Enable strict type checking.
• Formatting: Mandate Prettier via lint-staged and .prettierrc.
• Testing: Use Vitest (or Jest) for unit/integration testing. Target > 80% line coverage.
• Builds: Use tsup (library bundling) or Vite (web applications).
• TypeScript Config: Aim for strict: true long-term. For existing projects, migrate incrementally: start with strictNullChecks, then noImplicitAny, strictFunctionTypes. Do NOT flip strict: true in one step.
• CI/CD: Always run tsc --noEmit in build pipeline to catch type errors.
• Error Suppression: Favor @ts-expect-error over @ts-ignore for documented edge-cases.

ESLint Configuration

Enable @typescript-eslint/recommended at minimum. When strict: false in tsconfig, no-unsafe-* rules may produce excessive noise — suppress selectively with @ts-expect-error rather than disabling globally.

See reference for common linting issues (request typing, unused params, test mock typing) and tsconfig migration examples.