Mocha.js: Getting Started

Installing

$ npm install mocha
$ mkdir test
$ $EDITOR test/test.js # or open with your favorite editor

In your editor:

var assert = require('assert');
describe('Array', function () {
  describe('#indexOf()', function () {
    it('should return -1 when the value is not present', function () {
      assert.equal([1, 2, 3].indexOf(4), -1);
    });
  });
});

Back in the terminal:

$ ./node_modules/mocha/bin/mocha

  Array
    #indexOf()
      ✓ should return -1 when the value is not present


  1 passing (9ms)

Set up a test script in package.json:

"scripts": {
  "test": "mocha"
}

Then run tests with:

$ npm test