How to Setup Basic Node Server

Setup basic Node.js + Express.js server

Initialize the package manager

• Create any folder to contain the project, let say my-app
• Run npm init command at my-app folder location in terminal. Assuming you have Node installed. If not, please install.
• It will ask you the values of the properties of package.json.

• It will create a file called package.json with the content shown below.

{
  "name": "my-app",
  "version": "1.0.0",
  "description": "This is basic node express setup",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "Sanket Patel",
  "license": "ISC"
}

Install the express package

• To create an express server, we will need to install the package called express
• To do the same, run npm install express --save or if you prefer yarn then run yan add express

Create the server

• Let’s create index.js, which will be the main and entry point of the node server we are going to create.
• It will be having content as below:

const express = require("express");

//create express app
const app = express();

//port at which the server will run
const port = 4000;

//create end point
app.get("/", (request, response) => {
  //send 'Hi, from Node server' to client
  response.send("Hi, from Node server");
});

//start server and listen for the request
app.listen(port, () =>
  //a callback that will be called as soon as server start listening
  console.log(`server is listening at http://localhost:${port}`)
);

• To run the same run node index.js in the terminal. Which should show output as

$ node index.js
server is listening at http://localhost:4000

• And if you will click on http://localhost:4000 link, it will run our default route (’/’) and it will show the response message we sent from the server i.e.‘Hi, from Node server’.

Demystify the command

• Instead of running node index.js each time, we can create it’s a script in package.json, like below

...
"scripts": {
  "dev":"node index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
...

• Now you can simply run npm run dev or yarn dev to run the server. This will be really helpful when in real projects, we want to do many other things while starting the server.

Watch for the changes and automatically restart the server

• Currently, each time you make changes in the index.js, you will have to stop the server(using ctrl+c in windows, cmd+c in macOS I guess), and start again to see the effects.
• Instead, to keep watch on the file, we can use a package called nodemon. We can install it as dev dependency by running npm install nodemon --save-dev or yarn add nodemon --dev.
• And update the dev script in package.json to as shown below

...
"scripts": {
  "dev": "nodemon index.js", //use `nodemon` instead of `node`
    "test": "echo \"Error: no test specified\" && exit 1"
  },
...

• Now as soon as you make any change in the index.json, it will automatically detect the changes, it will stop and start the server. Try updating the response message to test the same.