Building REST APIs with Node.js

mkdir my-api && cd my-api
npm init -y
npm install express

const express = require('express');
const app = express();

app.use(express.json());

// In-memory data store
let todos = [
  { id: 1, title: 'Learn Node.js', completed: false },
  { id: 2, title: 'Build an API', completed: false },
];

// GET all todos
app.get('/api/todos', (req, res) => {
  res.json(todos);
});

// GET single todo
app.get('/api/todos/:id', (req, res) => {
  const todo = todos.find(t => t.id === parseInt(req.params.id));
  if (!todo) return res.status(404).json({ error: 'Not found' });
  res.json(todo);
});

// POST new todo
app.post('/api/todos', (req, res) => {
  const todo = {
    id: todos.length + 1,
    title: req.body.title,
    completed: false,
  };
  todos.push(todo);
  res.status(201).json(todo);
});

// DELETE todo
app.delete('/api/todos/:id', (req, res) => {
  todos = todos.filter(t => t.id !== parseInt(req.params.id));
  res.status(204).send();
});

app.listen(3000, () => console.log('API running on port 3000'));

// Global error handler
app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).json({
    error: 'Something went wrong',
    message: process.env.NODE_ENV === 'development' ? err.message : undefined,
  });
});

const { z } = require('zod');

const todoSchema = z.object({
  title: z.string().min(1).max(200),
  completed: z.boolean().optional(),
});