nodejs-minimal-setup

Node.js Project Initialization

If there is no node_modules/ directory in the root folder, run npm install.

To run the project, run:

npm start

To test the features, run:

npm test

---

initialization

In the terminal environment, type the following command to initialize the project:

npm init -y

-y shorthand flag: it should take all the defaults

configuration

package.json

After initialization, the project folder should contain a file named package.json.

npm config list

npm set init.author.name "<Your Name>"
npm set init.author.email "you@example.com"
npm set init.author.url "example.com"
npm set init.license "MIT"

index.js

In the project’s root folder, create a folder name src, and then in the src folder, create a file named index.js.

console.log("node.js is running");

nodemon

Nodemon helps with creating an always-running node process. Use the following command to install the package nodemon:

npm install nodemon --save-dev

Now package.json looks like this:

{
  ...
  "main": "index.js",
  "scripts": {
    "start": "nodemon src/index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  ...
}

Babel

Recent JavaScript language features (ECMAScript) are not included in the recent Node.js versions. Babel helps to transpile the code into Vanilla JavaScript. To install Babel, simply run:

npm install @babel/core @babel/node --save-dev

Next, add the npm start script to package.json:

{
  ...
  "main": "index.js",
  "scripts": {
    "start": "nodemon --exec babel-node src/index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  ...
}

After editing the package.json file, add the preset to the application configuration.

npm install @babel/preset-env --save-dev

In the project’s root directory, create a .babelrc file with the configuration:

{
  "presets": [
    "@babel/preset-env"
  ]
}

dotenv

In the project’s root directory, create a .dotenv file with any environmental variables:

MY_SECRET=hereismysecret

Then, in the terminal, install dotenv:

npm install dotenv --save

Import dotenv into src/index.js to use environment variables:

import 'dotenv/config';

console.log('nodemon src/index.js');

console.log(process.env.MY_SECRET);

Mocha and Chai for testing

Mocha will be our test runner which is responsible for encapsulating our tests in test suites (describe-block) and test cases (it-block). Chai will be our assertion library to run equality checks or other test related scenarios.

To install Mocha:

npm install @babel/register --save-dev

npm install mocha --save-dev

Then, in the package.json file, include a test script:

{
  ...
  "main": "index.js",
  "scripts": {
    "start": "nodemon --exec babel-node src/index.js",
    "test": "mocha --require @babel/register 'src/**/**spec.js'"
  },
  "keywords": [],
  ...
}

As we use ** in between, Mocha will run recursively through the src/ folder to find all files in the application.

To install Chai, run:

npm install chai --save-dev

Later, we can specify the first test file src/spec.js:

import { expect } from 'chai';

describe('true or false', () => {
  it('true is true', () => {
    expect(true).to.eql(true);
  });

  it('false is false', () => {
    expect(false).to.eql(false);
  });
});

Note that there are other packages for testing, such as sinon.