如何对jQuery Promises进行unit testing？

我有以下四个函数，当使用参数进行promise解析时，将调用two（），three（）和four（）。 让我再解释一下。

当我调用函数one（）时，我传递默认参数值，但函数two（）将在函数one（）中使用promise的解析值调用。 函数two（），three（）和four（）遵循类似的逻辑。

function one(arg) { var deferred = $.Deferred(); // Don't worry yet what this is until after you understand the flow console.log("Starting one's ajax with arg: " + arg); $.ajax({ url: '/', success: function() { // Here's where you want to call the next function in the // list if there is one. To do it, call deferred.resolve() console.log('Finished with one. Ready to call next.'); deferred.resolve("This is one's result"); } }); // The deferred object has a "promise" member, which has a "then" function return deferred.promise(); } function two(arg) { var deferred = $.Deferred(); console.log("Starting two's ajax with arg: " + arg); $.ajax({ url: '/', success: function() { // Again, this is where you want to call the next function // in the list if there is one. console.log('Finished with two. Ready to call next.'); deferred.resolve("This is two's result"); } }); // The deferred object has a "promise" member, which has a "then" function return deferred.promise(); } function three(arg) { var deferred = $.Deferred(); console.log("Starting three's ajax with arg: " + arg); $.ajax({ url: '/', success: function() { // Again, this is where you want to call the next function // in the list if there is one. console.log('Finished with three. Ready to call next if there is one.'); deferred.resolve("This is three's result"); } }); // The deferred object has a "promise" member, which has a "then" function return deferred.promise(); } function four(arg) { console.log("Starting four with arg: " + arg); console.log("Finished synchronous four"); } // Test it out. Call the first. Pass the functions (without calling them, so no parentheses) // into the "then" calls. one("arg given to one") .then(two) .then(three) .then(four); 

Answer 1

目前，你的测试太多了。 你真的想测试你的浏览器能够做AJAX吗？ 做什么的？

第一步是提取函数，以便在unit testing中调用/链接它们。 这样，您可以在unit testing中创建自己的promise，为它们提供函数并同步执行它们。

Answer 2

在考虑了@Aaron的建议之后，我尝试了以下unit testing代码，用于单个函数的成功场景，比如function一。

 describe('Test example-1', function () { it('should check promise resolved with a custom message', function () { spyOn($, 'ajax').andCallFake(function (req) { var d = $.Deferred(); d.resolve("I am done"); return d.promise(); }); var expectedPromise = one(); var result = "I am done"; expectedPromise.then(function(response) { expect(response).toEqual(result); }); }); }); 

我已经在我的github回购中推动了成功和失败的例子：

https://github.com/pulakb/UnitTesting-Promises/tree/master/Jasmine/jQuery