tomevault-io Express.js
Quick Start
import express from 'express';
import cors from 'cors';
import helmet from 'helmet';
const app = express();
app.use(helmet());
app.use(cors());
app.use(express.json());
app.get('/api/health', (req, res) => {
res.json({ status: 'ok' });
});
app.listen(3000);
Features
| Feature | Description | Guide |
|---|---|---|
| Project Setup | TypeScript config, middleware stack | SETUP.md |
| Routing | Controllers, validation, async handlers | ROUTING.md |
| Middleware | Auth, validation, error handling | MIDDLEWARE.md |
| Database | Prisma/TypeORM integration | DATABASE.md |
| Testing | Jest, supertest patterns | TESTING.md |
| Deployment | Docker, PM2, production config | DEPLOYMENT.md |
Common Patterns
Controller Pattern
// controllers/users.ts
import { Request, Response, NextFunction } from 'express';
import { UserService } from '../services/UserService';
export class UserController {
constructor(private userService: UserService) {}
getAll = async (req: Request, res: Response, next: NextFunction) => {
try {
const users = await this.userService.findAll();
res.json(users);
} catch (error) {
next(error);
}
};
getById = async (req: Request, res: Response, next: NextFunction) => {
try {
const user = await this.userService.findById(req.params.id);
if (!user) return res.status(404).json({ error: 'Not found' });
res.json(user);
} catch (error) {
next(error);
}
};
}
Error Handler
// middleware/errorHandler.ts
import { Request, Response, NextFunction } from 'express';
export class AppError extends Error {
constructor(
public statusCode: number,
message: string,
public isOperational = true
) {
super(message);
}
}
export function errorHandler(
err: Error,
req: Request,
res: Response,
next: NextFunction
) {
if (err instanceof AppError) {
return res.status(err.statusCode).json({ error: err.message });
}
console.error(err);
res.status(500).json({ error: 'Internal server error' });
}
Validation Middleware
// middleware/validate.ts
import { Request, Response, NextFunction } from 'express';
import { ZodSchema } from 'zod';
export function validate(schema: ZodSchema) {
return (req: Request, res: Response, next: NextFunction) => {
const result = schema.safeParse({
body: req.body,
query: req.query,
params: req.params,
});
if (!result.success) {
return res.status(400).json({ errors: result.error.issues });
}
next();
};
}
Workflows
API Development Workflow
- Define routes in
routes/index.ts - Create controller with business logic
- Add validation schemas with Zod
- Write tests with supertest
- Document with OpenAPI/Swagger
Middleware Order
1. Security (helmet, cors)
2. Rate limiting
3. Body parsing
4. Logging
5. Authentication
6. Routes
7. 404 handler
8. Error handler
Best Practices
| Do | Avoid |
|---|---|
| Use async/await with try-catch | Callback patterns |
| Validate all inputs | Trusting client data |
| Use typed request/response | any types |
| Centralize error handling | Scattered try-catch |
| Use dependency injection | Direct imports in controllers |
Project Structure
src/
├── app.ts # Express setup
├── server.ts # Server entry
├── config/ # Environment config
├── controllers/ # Route handlers
├── middleware/ # Custom middleware
├── routes/ # Route definitions
├── services/ # Business logic
├── utils/ # Helpers
└── types/ # TypeScript types
For detailed examples and patterns, see reference files above.
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