done() 的用途和使用方法(量角器、茉莉花) [英] what done() is for and how to use it ( protractor, jasmine)

问题描述

it('should for something', function check(done) {
  browser.sleep(2000);
  $('.csTx').isPresent().then(function(result) {
    if(result) {
      done();
    } else {
      xPage.clickBack();
      check(done);
    }
  })
}, 30000);

有人可以解释 done() 是如何工作的，以及它是做什么用的.我用谷歌搜索了它，但找不到任何容易让我理解的信息.我正在使用量角器和茉莉花进行自动化.请考虑上面的代码.

Can someone explain how done() works and what this is for. I googled it but cannot find any information that would be easy enough for me to understand. I am automating with protractor and jasmine. please consider the above code.

推荐答案

如果您的测试在您的测试的控制流中创建了一个并行任务队列，您需要使用 done(阅读更多关于 承诺和控制流程).

You need to use done if your test creates a parallel TaskQueue in your test's Control Flow (read more about promises and control flow).

例如:

describe('Control Flow', function() {
    function logFromPromise(text) {
        var deferred = protractor.promise.defer();
        deferred.then(function() {
            console.log(text);
        });
        deferred.fulfill();
        return deferred;
    }

    it('multiple control flows', function() {
        setTimeout(function() {
            logFromPromise('1');
        });
        logFromPromise('0');
    });
}

调用setTime在控件中创建一个并行任务队列:

Calling setTime creates a parallel Task Queue in the control:

ControlFlow
| TaskQueue
| | Task<Run fit("multiple control flows") in control flow>
| | | TaskQueue 
| | | | Task <logFromPromise('0');>
| TaskQueue
| | Task <setTimeout>

在打印 0 后，Protractor 认为测试完成".在这个例子中，1 可能会在测试完成后被打印出来.要让量角器等待Task <setTimeout>，需要调用done函数:

Protractor thinks the test is "done" after 0 is printed. In this example, 1 will probably be printed after the test is completed. To make protractor wait for Task <setTimeout>, you need to call the done function:

    it('multiple control flows', function(done) {
        setTimeout(function() {
            logFromPromise('1').then(function() {
                done();
            });
        });
        logFromPromise('0');
    });

如果可以，请在完成"测试时让量角器处理.拥有并行任务队列可能会导致测试中出现意外的竞争条件.

If you can, let protractor handle when the test is "done". Having parallel TaskQueues can lead to unexpected race conditions in your test.

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