Node JS Express API

Node.js Express API Skill

REST API Patterns

Route Structure

Organize routes by resource (e.g., /api/stocks, /api/market, /api/health).

// routes/stocks.js
const express = require('express');
const router = express.Router();

router.get('/', async (req, res, next) => {
  try {
    const data = await stockService.getAll();
    res.json({ success: true, data });
  } catch (error) {
    next(error);
  }
});

module.exports = router;

Error Handling Middleware

Always use centralized error handling:

// middleware/errorHandler.js
const errorHandler = (err, req, res, next) => {
  console.error(err.stack);
  res.status(err.status || 500).json({
    success: false,
    error: err.message || 'Internal Server Error'
  });
};

Middleware Patterns

Request Validation

const validateRequest = (schema) => (req, res, next) => {
  const { error } = schema.validate(req.body);
  if (error) return res.status(400).json({ error: error.message });
  next();
};

Rate Limiting

const rateLimit = require('express-rate-limit');
const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100
});
app.use('/api/', limiter);

Background Job Scheduling

Using node-cron

const cron = require('node-cron');

// Run every 5 minutes during market hours (10 AM - 3 PM Nepal time)
cron.schedule('*/5 10-15 * * 0-4', async () => {
  await updateStockData();
}, { timezone: 'Asia/Kathmandu' });

Using node-schedule

const schedule = require('node-schedule');

// Run at specific times
const job = schedule.scheduleJob('0 10 * * 0-4', async () => {
  await marketOpenTasks();
});

Best Practices

1. Use async/await - Always wrap async handlers in try-catch
2. Validate input - Never trust user input
3. Log everything - Use Winston or similar for structured logging
4. Use environment variables - Never hardcode secrets
5. Implement health checks - /api/health endpoint for monitoring

Source: Rojan248/nepse-stock-website — distributed by TomeVault.