Learning Objective:

• In this lesson, we will learn how to move constants to a separate file.

  • Hardcoding values is a BAD Practice ( e.g: const port = 5000)
  • Maintain constants in a separate file, so that its easy to change

Install dotenv

• https://www.npmjs.com/package/dotenv ( 11M Weekly Downloads)

    npm i dotenv

Task 1: Manage port in constant file ( Create .env file)

• .env file

    PORT=3000

Task 2: Use the PORT in app.js

• New Code:

    const dotenv = require('dotenv');
    dotenv.config()

    const port = process.env.PORT;
    console.log("PORT", port);

Testing #1: Run the Server

    nodemon app.js

  D:\restapi-lab\project-api>nodemon app.js
  [nodemon] 2.0.4
  [nodemon] to restart at any time, enter `rs`
  [nodemon] watching path(s): *.*
  [nodemon] watching extensions: js,mjs,json
  [nodemon] starting `node app.js`
  Server is listening on port 3000!

Task 3: Change the port (e.g: from 3000 to 5000 ) in constant file

• .env file

    PORT=5000

• Output:

  D:\restapi-lab\project-api>nodemon app.js
  [nodemon] 2.0.4
  [nodemon] to restart at any time, enter `rs`
  [nodemon] watching path(s): *.*
  [nodemon] watching extensions: js,mjs,json
  [nodemon] starting `node app.js`
  Server is listening on port 5000!

Git Instructions

  git status
  git app.js
  git commit -m "Refactoring - Added PORT in environment variable"

Summary

• Successfully, we have refactored our code and managed the constants in a separate file.