Guided Practice - Playlist

In this guided practice, we'll use Express to create a simple API that serves information about a playlist of songs.

Getting Started

1. Create a new repository using this one as a template.
2. Clone down your repository and run npm install to install the dependencies.
3. Start the development server with npm run dev.

Setting Up Express

1. In server.js, import the "express" package and call it to create the Express app.

   See solution

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

2. Initialize a PORT variable to 3000, which is a common default port that local servers listen on.

   See solution

   const PORT = 3000;

3. Write middleware to handle the GET / endpoint. It should respond with the message "You've reached the Playlist API!".

   See solution

   app.get("/", (req, res) => {
     res.send("You've reached the Playlist API!");
   });

4. Tell the app to listen on PORT. A corresponding status message should be logged to the console, which you should see if your development server is running.

   See solution

   app.listen(PORT, () => {
     console.log(`Listening on port ${PORT}.`);
   });

5. Use the REST Client Extension to test the GET / endpoint in playlist.http. If you've done everything correctly, the server should respond with the correct message!

Serving Playlist

1. An array of songs has already been initialized in playlist.js. At the bottom of that file, add a line to export that array.

   See solution

   module.exports = playlist;

2. Back in server.js, import that array using require. Now that our server has access to this data, we can use it in our responses.

   See solution

   const playlist = require("./playlist");

3. Write middleware to handle the GET /playlist endpoint. It should respond with the playlist array as JSON. Use playlist.http to test this endpoint.

   See solution

   app.get("/playlist", (req, res) => {
     res.json(playlist);
   });

4. Write middleware to handle the GET /playlist/:index endpoint. It should respond with the song at the given index of the playlist array. If the index is invalid, it should send the message "That song does not exist in the playlist." with status code 404. Use playlist.http to test this endpoint.

   See solution

   app.get("/playlist/:index", (req, res) => {
     const { index } = req.params;
     if (index < 0 || index >= playlist.length) {
       res.status(404).send("That song does not exist in the playlist.");
     } else {
       res.json(playlist[index]);
     }
   });

Solution

To view the full solution, switch over to the solution branch of this starter repository.