Setting up jwt authentication, routes and a postgres connection

bash 
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npm init -y
npm install prisma @prisma/client bcrypt jsonwebtoken dotenv express
npm install -D typescript ts-node @types/express @types/node @types/bcrypt @types/jsonwebtoken

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DATABASE_URL="postgresql://USER:PASSWORD@localhost:5432/DB_NAME?schema=public"
JWT_SECRET="your_jwt_secret_key"

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node -e "console.log(require('crypto').randomBytes(32).toString('hex'))"

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openssl rand -hex 32

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// prisma/schema.prisma
generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "postgresql"
  url      = env("DATABASE_URL")
}

model User {
  id       Int     @id @default(autoincrement())
  email    String  @unique
  password String
  name     String?
}

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npx prisma migrate dev --name init

javascript 
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import bcrypt from "bcrypt";
import jwt from "jsonwebtoken";

const saltRounds = 10;

// Hash password
export const hashPassword = async (password) => {
  return await bcrypt.hash(password, saltRounds);
};

// Compare password
export const comparePassword = async (password, hash) => {
  return await bcrypt.compare(password, hash);
};

// Generate JWT token
export const generateToken = (userId) => {
  return jwt.sign({ userId }, process.env.JWT_SECRET, { expiresIn: "1h" });
};

// // Verify a token
export const validateToken = (req, res, next) => {
  const token = req.headers.authorization?.split(" ")[1];
  if (!token) return res.status(401).json({ error: "Unauthorized" });

  try {
    const decoded = jwt.verify(token, process.env.JWT_SECRET);
    req.user = decoded;
    next();
  } catch (error) {
    res.status(401).json({ error: "Invalid token" });
  }
};

javascript 
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import express from 'express';
import { PrismaClient } from '@prisma/client';
import { hashPassword, comparePassword, generateToken } from './utils/auth';

const prisma = new PrismaClient();
const app = express();
app.use(express.json());

// Register a new user
app.post('/register', async (req, res) => {
  const { email, password, name } = req.body;

  try {
    const hashedPassword = await hashPassword(password);
    const user = await prisma.user.create({
      data: {
        email,
        password: hashedPassword,
        name,
      },
    });

    res.status(201).json({ id: user.id, email: user.email });
  } catch (error) {
    res.status(400).json({ error: 'User already exists' });
  }
});

// Login
app.post('/login', async (req, res) => {
  const { email, password } = req.body;

  const user = await prisma.user.findUnique({ where: { email } });
  if (!user) return res.status(404).json({ error: 'User not found' });

  const isValid = await comparePassword(password, user.password);
  if (!isValid) return res.status(401).json({ error: 'Invalid password' });

  const token = generateToken(user.id);
  res.json({ token });
});

const PORT = 3000;
app.listen(PORT, () => console.log(`Server running on port ${PORT}`));