| /*! |
| * Chai - addProperty utility |
| * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com> |
| * MIT Licensed |
| */ |
| |
| var chai = require('../../chai'); |
| var flag = require('./flag'); |
| var isProxyEnabled = require('./isProxyEnabled'); |
| var transferFlags = require('./transferFlags'); |
| |
| /** |
| * ### .addProperty(ctx, name, getter) |
| * |
| * Adds a property to the prototype of an object. |
| * |
| * utils.addProperty(chai.Assertion.prototype, 'foo', function () { |
| * var obj = utils.flag(this, 'object'); |
| * new chai.Assertion(obj).to.be.instanceof(Foo); |
| * }); |
| * |
| * Can also be accessed directly from `chai.Assertion`. |
| * |
| * chai.Assertion.addProperty('foo', fn); |
| * |
| * Then can be used as any other assertion. |
| * |
| * expect(myFoo).to.be.foo; |
| * |
| * @param {Object} ctx object to which the property is added |
| * @param {String} name of property to add |
| * @param {Function} getter function to be used for name |
| * @namespace Utils |
| * @name addProperty |
| * @api public |
| */ |
| |
| module.exports = function addProperty(ctx, name, getter) { |
| getter = getter === undefined ? function () {} : getter; |
| |
| Object.defineProperty(ctx, name, |
| { get: function propertyGetter() { |
| // Setting the `ssfi` flag to `propertyGetter` causes this function to |
| // be the starting point for removing implementation frames from the |
| // stack trace of a failed assertion. |
| // |
| // However, we only want to use this function as the starting point if |
| // the `lockSsfi` flag isn't set and proxy protection is disabled. |
| // |
| // If the `lockSsfi` flag is set, then either this assertion has been |
| // overwritten by another assertion, or this assertion is being invoked |
| // from inside of another assertion. In the first case, the `ssfi` flag |
| // has already been set by the overwriting assertion. In the second |
| // case, the `ssfi` flag has already been set by the outer assertion. |
| // |
| // If proxy protection is enabled, then the `ssfi` flag has already been |
| // set by the proxy getter. |
| if (!isProxyEnabled() && !flag(this, 'lockSsfi')) { |
| flag(this, 'ssfi', propertyGetter); |
| } |
| |
| var result = getter.call(this); |
| if (result !== undefined) |
| return result; |
| |
| var newAssertion = new chai.Assertion(); |
| transferFlags(this, newAssertion); |
| return newAssertion; |
| } |
| , configurable: true |
| }); |
| }; |