Registration

Goal

This snapshot advances Copperline Journal by teaching you to validate accounts and store bcrypt password hashes.

Every numbered folder is a complete app. Run this stage independently, then compare it with the previous folder to see the new responsibility clearly.

Prerequisites

Use Node.js 20 or newer, npm, and a terminal. You should recognize basic JavaScript functions, objects, and HTTP requests.

Port 3000 must be available. MongoDB snapshots use Docker locally; copy the example environment file before starting them.

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

Concepts

Registration normalizes identifiers, checks uniqueness, validates input, and stores a one-way password hash—never a raw password.

Keep responsibilities visible: middleware prepares requests, routes choose handlers, models protect data rules, and EJS views present escaped values.

Walkthrough

Validate username, email, and password; check existing users; hash with bcrypt; save; then redirect to login.

Read the example from input to output, then inspect the matching snapshot. The repository includes the surrounding setup and error handling.

const user = new User({ username, email, displayName: username });
await user.setPassword(password);
await user.save();

Run and verify

Enter 06-Registration, install its dependencies, copy .env.example when present, and start the server.

Open http://localhost:3000. Keep the terminal visible so route, validation, and database errors can be connected to the browser action that caused them.

docker compose up -d
git clone https://github.com/michaeldunga1/fcc-express-blog.git
cd fcc-express-blog/06-Registration
npm install
cp .env.example .env
npm start
# optional: npm run seed

Troubleshooting

Duplicate-key errors still require handling because two requests can pass an earlier availability check at the same time.

A missing-module error usually means npm install ran in another snapshot. For database failures, check the container and that this folder uses its own Copperline database name.

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

Try this

Try mixed-case email, a short password, and a duplicate username.

Test a happy path and one invalid or unauthorized request. Useful applications return clear feedback without exposing secrets or stack traces.

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