Routing

Goal

This snapshot advances Copperline Journal by teaching you to organize page routes with an Express Router.

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

Routers group related endpoints and can be mounted under a common path. Route order matters because Express matches top to bottom.

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

Walkthrough

Move home, about, and sample post handlers into a router, mount it from the app, and add a final 404 handler.

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

const router = require("express").Router();
router.get("/", home);
router.get("/about", about);
app.use("/", router);

Run and verify

Enter 02-Routing, 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.

git clone https://github.com/michaeldunga1/fcc-express-blog.git
cd fcc-express-blog/02-Routing
npm install
cp .env.example .env
npm start

Troubleshooting

A broad parameter route can capture a specific path if it appears first. Check the HTTP method and mount path together.

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

Add a named /contact route and verify an unknown path returns 404.

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