Getting started with mocha

Remarks#

This section provides an overview of what mocha is, and why a developer might want to use it.

It should also mention any large subjects within mocha, and link out to the related topics. Since the Documentation for mocha is new, you may need to create initial versions of those related topics.

Installation or Setup

You can install mocha either globally or in your project folder. The latter is the preferred way. In all the example let’s assume that all the test files are in a test folder within the project folder.

Install Mocha locally

To install mocha in your project folder, you can use the following npm command:

$ cd my-project/folder
$ npm install mocha --save-dev

This command will install mocha inside the node_modules folder in your project and add a (development) dependency entry inside the package.json file.

Use mocha in the CLI

To use mocha from the CLI you can either use the mocha command inside the ./node_modules/.bin/ folder:

$ ./node_modules/.bin/mocha ./test

Or use a npm script (a npm script uses by default the commands in the .bin folder).

# package.json
{
 "name": "my-project",
 "version": "0.0.1",
 "description": "my first tested project",
 "scripts": {
    "start": "node app.js",
    "test": "mocha ./test"
 },
 ...
}

To call that script you can do now:

$ npm run test

Or simply (test is a special script in npm):

$ npm test

Use mocha in a webpage

To use mocha inside a webpage (just front-end), just include the mocha.js file inside node_modules/mocha/mocha.js inside your webpage:

## HTML page with tests
<script src="node_modules/mocha/mocha.js"></script>

Install mocha globally

For a global install use npm as follow:

$ npm install mocha -g

This will install mocha in your global environment and bind the mocha command to your CLI., so you can call mocha from the terminal in any place.

$ mocha ./test

Mocha example for string split method

var assert = require('assert');

describe('String', function() {
    describe('#split', function() {
      it('should return an array', function() {
        assert(Array.isArray('a,b,c'.split(',')))
      });
    });
});