| 'use strict'; | |
| 
 | |
| module.exports = { | |
|   isString: function (arg) { | |
|     return typeof arg === 'string'; | |
|   }, | |
|   isObject: function (arg) { | |
|     return typeof arg === 'object' && arg !== null; | |
|   }, | |
|   isNull: function (arg) { | |
|     return arg === null; | |
|   }, | |
|   isNullOrUndefined: function (arg) { | |
|     return arg == null; | |
|   } | |
| };
 |