In this project, we will create a node server that will act as a bookshelf. This server will keep track of books by being able to add books to a collection, read from the collection, update the collection, and delete from the collection. We'll use postman to test our endpoints.

• Fork this repository.
• Clone your fork.

In this step, we will create a package.json to keep track of our server's packages.

• Run npm init -y.

In this step, we will install the most common packages you'll use when making a node server.

• Run npm install express

In this step, we will create a .gitignore file to ignore the node_modules folder npm install created.

• Create a .gitignore file in the root of the project.
• Add node_modules on the first line and save the file.

node_modules

In this step, we will create our server and have it listen on port 4000.

• In the root of the directory create a folder called server.
• Create an index.js file in server/.
• Open server/index.js.
• Require express in a variable called express.
• Create a variable called app that equals express invoked.
• Call the use method on app and pass in the express.json method invoked.
• Call the listen method on app. The app should listen on port 4000:
  • The first parameter of listen is the port number.
  • The second parameter of listen is a function that is called when the app starts listening.

const express = require('express');

const app = express();

app.use(express.json());

const port = 4000;
app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

In this step, we will create a controller that keeps track of the book collection and import that controller into server/index.js.

• Create a folder in server/ called controllers.
• In server/controllers/ create a file called books_controller.js.
• Open server/controllers/books_controller.js.
• Create a variable called books that equals an empty array.
  • The books variable will keep track of all our books. A book will be an object that has an id, title, and author property.
• Create a variable called id that equals 0.
  • After a creation of a book, we will increment this by 1 to insure no books have the same id.
• Use module.exports to export an object.
• Open server/index.js.
• Require the books controller at the top of server/index.js in a variable called bc.

let books = [];
let id = 0;

module.exports = {};

const express = require("express");
const bc = require("./controllers/books_controller.js");

const app = express();

app.use(express.json());

const port = 4000;
app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

In this step, we will create the endpoint to get all the books. We will also create the method in the books_controller to be used as the endpoint's handler function.

When creating a get route, you can use the get method on the app object. The first argument is the URL of the request and the second argument is the function to execute when that URL is hit. We will be getting that function from the books_controller.

• Open server/index.js.
• Below the top level middleware and above the listen method invocation, add a get endpoint.
  • The URL path should be /api/books.
  • The handler function will come from the books_controller, we will add it once we create it.
• Open server/controllers/books_controller.js.
• Create a method called read in the module.exports object.
  • This method should return all the books.
• Return to the get endpoint in server/index.js that we just wrote and add the read method as the second argument after the URL path.

let books = [];
let id = 0;

module.exports = {
  read: (req, res) => {
    res.status(200).send(books);
  }
};

const express = require("express");
const bc = require("./controllers/books_controller.js");

const app = express();

app.use(express.json());

app.get("/api/books", bc.read);

const port = 4000;
app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

In this step, we will create the endpoint to post a new book. We will also create the method in the books_controller to be used as the endpoint's handler function.

• Open server/index.js.
• Below the get endpoint, add a post endpoint.
  • The URL path should be /api/books.
  • The handler function will come from the books_controller, we will add it once we create it.
• Open server/controllers/books_controller.js.
• Create a method called create in the module.exports object.
  • This method should add a new book from the request body to the books array.
  • When finished, it should return all the books.
  • Keep in mind, the information you'll be getting from the request body are title and author. You'll have to add your own id property with the value coming from the id variable. Don't forget to increment the id variable when you're done.
• Return to the post endpoint in server/index.js that we just wrote and add the create method as the second argument after the URL path.

let books = [];
let id = 0;

module.exports = {
  read: (req, res) => {
    res.status(200).send(books);
  },
  create: (req, res) => {
    const { title, author } = req.body;
    let book = {
      id: id,
      title: title,
      author: author
    }
    books.push(book);
    id++;
    res.status(200).send(books);
  }
};

const express = require("express");
const bc = require("./controllers/books_controller.js");

const app = express();

app.use(express.json());

app.get("/api/books", bc.read);
app.post("/api/books", bc.create);

const port = 4000;
app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

In this step, we will create a put endpoint to update a specific book by it's id. We will also create the method in the books_controller to be used as the endpoint's handler function.

• Open server/index.js.
• Below the post endpoint, add a put endpoint.
  • You will be using the params object in this endpoint, specifically an id you'll get from the URL parameters. Make sure to indicate this at the end of the URL path /api/books.
  • The handler function will come from the books_controller, we will add it once we create it.
• Open server/controllers/books_controller.js.
• Create a method called update in the module.exports object.
  • This method should find a specific book based off of an id that you'll get off of the params object.
  • Once the book is found, update the book with the new information you'll get off of the request body.
  • Return all the books.
• Return to the put endpoint in server/index.js that we just wrote and add the update method as the second argument after the URL path.

let books = [];
let id = 0;

module.exports = {
  read: (req, res) => {
    res.status(200).send(books);
  },
  create: (req, res) => {
    const { title, author } = req.body;
    let book = {
      id: id,
      title: title,
      author: author
    };
    books.push(book);
    id++;
    res.status(200).send(books);
  },
  update: (req, res) => {
    let index = null;
    books.forEach((book, i) => {
      if (book.id === Number(req.params.id)) index = i;
    });
    books[index] = {
      id: books[index].id,
      title: req.body.title || books[index].title,
      author: req.body.author || books[index].author
    };
    res.status(200).send(books);
  }
};

const express = require("express");
const bc = require("./controllers/books_controller.js");

const app = express();

app.use(express.json());

app.get("/api/books", bc.read);
app.post("/api/books", bc.create);
app.put("/api/books/:id", bc.update);

const port = 4000;
app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

In this step, we will create a delete endpoint to delete a specific book by it's id. We will also create the method in the books_controller to be used as the endpoint's handler function.

• Open server/index.js.
• Below the put endpoint, add a delete endpoint.
  • You will be using the params object in this endpoint, specifically an id you'll get from the URL parameters. Make sure to indicate this at the end of the URL path /api/books.
  • The handler function will come from the books_controller, we will add it once we create it.
• Open server/controllers/books_controller.js.
• Create a method called delete in the module.exports object.
  • This method should find a specific book based off of an id that you'll get off of the params object.
  • Once the book is found, remove that book from the books array.
  • Return all the books.
• Return to the delete endpoint in server/index.js that we just wrote and add the delete method as the second argument after the URL path.

let books = [];
let id = 0;

module.exports = {
  read: (req, res) => {
    res.status(200).send(books);
  },
  create: (req, res) => {
    const { title, author } = req.body;
    let book = {
      id: id,
      title: title,
      author: author
    };
    books.push(book);
    id++;
    res.status(200).send(books);
  },
  update: (req, res) => {
    let index = null;
    books.forEach((book, i) => {
      if (book.id === Number(req.params.id)) index = i;
    });
    books[index] = {
      id: books[index].id,
      title: req.body.title || books[index].title,
      author: req.body.author || books[index].author
    };
    res.status(200).send(books);
  },
  delete: (req, res) => {
    let index = null;
    books.forEach((book, i) => {
      if (book.id === Number(req.params.id)) index = i;
    });
    books.splice(index, 1);
    res.status(200).send(books);
  }
};

const express = require("express");
const bc = require("./controllers/books_controller.js");

const app = express();

app.use(express.json());

app.get("/api/books", bc.read);
app.post("/api/books", bc.create);
app.put("/api/books/:id", bc.update);
app.delete("/api/books/:id", bc.delete);

const port = 4000;
app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

In this step, we will use Postman Unit Tests to test our endpoints.

• Start up (or restart) your server.
• Open Postman.
• Click on the Import button and then click on Choose Files.
• Select the postman_collection.json file from the root of the project.
• Click on the arrow next to the node_introduction collection and click on Run.
• In the new Postman window make sure node_introduction is highlighted in orange and then press Start Test.
  • It's important to know that if you try to run the tests again, you must restart your server first or your tests will fail.

In this step, we will use express.static to serve up our index.html file. express.static takes an argument that is the location of the folder with the files you want to serve when the server URL is hit in a browser. Our front-end was made using create-react-app and instead of running it's own server, we have made a production ready build so that our server can serve up our frontend. We'll want to serve the entire build folder.

• Call the use method on app and pass in express.static( __dirname + '/../build').
• Add some books to your collection using Postman.
• Open up http://localhost:4000 in your browser.

const express = require("express");
const bc = require("./controllers/books_controller.js");

const app = express();

app.use(express.json());
app.use(express.static(__dirname + "/../build"));

app.get("/api/books", bc.read);
app.post("/api/books", bc.create);
app.put("/api/books/:id", bc.update);
app.delete("/api/books/:id", bc.delete);

const port = 4000;
app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

If you see a problem or a typo, please fork, make the necessary changes, and create a pull request so we can review your changes and merge them into the master repo and branch.

© DevMountain LLC, 2017. Unauthorized use and/or duplication of this material without express and written permission from DevMountain, LLC is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to DevMountain with appropriate and specific direction to the original content.