mocha Getting started with mocha

Remarks

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(',')))
      });
    });
});