This is a simple, minimal boilerplate for building APIs using TypeScript and Express with native ESM module support.
It includes unit and end-to-end testing out of the box, making it a great starting point for new projects or learning purposes.
- Express.js + TypeScript (with ESM)
- Typed API routes with DTOs (Data Transfer Objects)
- Unit testing with Jest
- End-to-End testing with Supertest
- Hot-reloading during development
- Simple, scalable, and easy-to-extend project structure
src/ │ ├── mocks/ → Mocks for unit testing ├── tests/ → Unit tests for route handlers │ └── handlers/ │ ├── e2e/ → End-to-End tests (Supertest) ├── dtos/ → Data Transfer Objects (DTOs) ├── handlers/ → Route handlers (controller logic) ├── routes/ → Express routes (API endpoints) ├── types/ → Shared TypeScript types │ ├── createApp.ts → App factory (for testing & production) └── index.ts → Main application entry point
| Command | Purpose |
|---|---|
npm run build |
Transpile TypeScript into JavaScript (dist/) |
npm start |
Run the compiled app from dist/ |
npm run start:dev |
Start in development mode with hot reload |
npm test |
Run all tests (unit + E2E) |
npm run test:e2e |
Run only End-to-End tests |
npm install
2. Build the Project (Transpile TypeScript → JavaScript)
npm run build
3. Start the Compiled App
npm start
✅ Development Mode (No Build Needed)
Run the app in development with hot reload and TypeScript:
npm run start:dev
✅ Running Tests
All Tests:
npm test
E2E Tests Only:
npm run test:e2e
⚠️ Requirements
Node.js v18 or higher (for native ESM support)
ℹ️ Notes
This project is designed for educational purposes, testing, or as a lightweight starting point for new TypeScript Express APIs.
🙋 About This Repo
This project was created to explore a clean, minimal API setup with TypeScript, ESM modules, and testing.
Feel free to fork or extend it for your own needs!