1 var assert = require('chai').assert; 2  3 describe('Array', function() { 4   describe('#indexOf()', function() { 5     it('should return -1 when the value is not present', function() { 6          7         var obj = {}; 8         var array  = [];  9         var date = new Date();10 11         var fn = function() {12         }13         14         var _null = null;15         16         assert.equal('[object Object]', Object.prototype.toString.call(obj));17         assert.equal('[object Array]', Object.prototype.toString.call(array));18         assert.equal('[object Date]', Object.prototype.toString.call(date));19         assert.equal('[object Function]', Object.prototype.toString.call(fn));20         21         assert.equal('[object Null]', Object.prototype.toString.call(_null));22     });23   });24 });