A sample test using mocha and chai. To execute, add it into your directory and make sure file name contains a string "test".

Mocha test demo

'use strict';

var chai = require('chai');
var expect = chai.expect;


describe('Array', function() {
    describe('#indexOf()', function () {
        it('should return -1 when the value is not present', function () {
            expect([1,2,3].indexOf(5)).to.equal(-1);
            expect([1,2,3].indexOf(0)).to.equal(-1);
        });
    });
});