Login and Sessions

Goal

This snapshot advances Circuit Daily by teaching you to authenticate with Passport local and express-session.

Every numbered folder is a complete app. Run this stage independently, then compare it with the previous folder.

Prerequisites

Use Node.js 20+, npm, and a terminal. You should recognize TypeScript modules, decorators, and HTTP verbs.

Port 3001 must be free. Copy .env.example before starting database stages.

• Node.js and npm
• A code editor and terminal
• Docker from part 4 onward

Concepts

Passport local verifies credentials; express-session stores an opaque cookie. Keep only the user id in the session.

Keep controllers thin: accept input, call services, render Handlebars views. Escape stays on by default in templates.

Walkthrough

Verify email/password, establish the session, and destroy it on logout.

Read the example, then open the matching snapshot. The repository includes the surrounding setup and error handling.

req.login(user, () => res.redirect('/'));

Run and verify

Enter 07-Login-And-Sessions, install dependencies, copy .env.example when present, and start Nest on port 3001.

Open http://127.0.0.1:3001. Watch the terminal for validation and database errors.

docker compose up -d
git clone https://github.com/michaeldunga1/fcc-nestjs-blog.git
cd fcc-nestjs-blog/07-Login-And-Sessions
npm install
cp .env.example .env
npm run start:dev

Troubleshooting

Session middleware must be registered before Passport. Changing SESSION_SECRET invalidates cookies.

Missing-module errors usually mean npm install ran in another snapshot. For Postgres failures, confirm Docker and the circuit_NN database name.

• Read the first error first
• Restart after environment changes
• Never commit .env or node_modules

Try this

Log in, restart Nest, confirm the session persists, then log out.

Test a happy path and one invalid or unauthorized request.

• Make one small change
• Test it in the browser
• Compare with the next snapshot only after it works