javascript - Jasmine 2.0 无法设置回调时的异步测试

Question

Jasmine 2.0 中对异步测试的更改在很多方面都很棒。但是，当我无法将回调绑定(bind)到异步方法时，我不确定我是否完全理解如何测试异步代码。

如何在 Jasmine 2.0 中针对未知数量的异步事件进行测试？或不提供回调调用的并行异步事件。

在 1.3 中我会这样做:

describe("my spec", function () {
   it("should check the state of a variable after unknown number of async events", function () {

        // This will execute several async functions in parallel (more than 1).
        // Once they are all complete the 'window.done' variable will be set to "true".
        // This method does not provide a callback.
        fire_parallel_async_methods();

        waitsFor(function () {
            // I know that once this condition is met,
            // all the above async calls are done
            return window.done === true;
        });

        runs(function () {
            // Now I can run the rest of my unit tests
        });
   });
});

Tony 的答案是 Jasmine 2.0: refactoring out 1.3's runs() and waitsFor()唯一的解决方案？

另一个用例是事件验证。例如:

describe("my spec", function () {
   it("should make sure event is fired", function () {

        // This element has an event binding on 'click' which changes its class.
        // In this test I want to check to make sure the event does the right thing.
        var $element = $('.some-element');

        // Simulate a click
        $element.simulate('click');
        // or $element.click();

        waitsFor(function () {
            // Once the event is done, the element should have a new 'after-event' class
            return $element.hasClass('after-event');
        });
   });
});

在此示例中，我无法访问事件的绑定(bind)，因此无法将回调附加到它。我将如何在 Jasmine 2.0 中验证这一点？

Answer 1

我能够找到使用超时的解决方法，它模仿 waitsFor() 行为:

describe("my spec", function () {
   it("should make sure event is fired", function (done) {

        // This element has an event binding on 'click' which changes its class.
        // In this test I want to check to make sure the event does the right thing.
        var $element = $('.some-element');

        // Simulate a click
        $element.simulate('click');
        // or $element.click();

        // Set a timeout to wait for the async event to go through.
        // Pick a time here that will be enough. It's a little messy, but it works for cases
        // where you can't attach a callback. The hardest part is figuring out how long to set
        // the timeout for.
        setTimeout(function () {
            // Do your test here
            expect($element).toHaveClass('after-event');

            // Tell Jasmine the test is finished
            done();
        }, 500);
   });
});