量角器 - 在执行下一步之前等待异步承诺 [英] Protractor - Wait for async promise before doing next

问题描述

首先，我已经查看了关于这一点的各种帖子和博客，但我仍然无法弄清楚如何正确地做到这一点.

First of all, I've already checked various post and blogs concerning that point and I still can't figure out how to make it correctly.

我尝试了许多不同的组合:

I have tried many different combinaison of :

• 浏览器等待
• protractor.controlFlow().execute
• 量角器.controlFlow().await(

...仍然没有成功..

...Still no success..

我的问题

在我的 beforeEach 函数中，我想调用量角器承诺并等待它解决，然后再执行我的其余代码.

Within my beforeEach function, I'd like to call a protractor promise and wait for it to resolve before performing the rest of my code.

我的代码

我已经为愿意帮助我的人准备了这个简单的测试

I've prepared this simple test for anyone willing to help me

describe('testAsync', function() {

  beforeEach(function() {
    console.log('beforeEach - step 1 ')

    browser.get("https://angularjs.org/");
    console.log('beforeEach - step 2 ')
    testFunc()
    console.log('beforeEach - after testFunc - step 3')

  });

  var testFunc = function(){

    console.log("testFunc - step 1")

    browser.wait(function() {
      var deferred = protractor.promise.defer();
      element(by.id('twitter-widget-1')).isPresent()
        .then(function (isPresent) {
          console.log("testFunc - step 2")
          deferred.fulfill(isPresent);
      });
      return deferred.promise;
    });

    console.log("testFunc - step 3")

  }

  it('test after BeforeEach', function() {
    console.log("Last trace")
  });

});

电流输出

[launcher] Running 1 instances of WebDriver
beforeEach - step 1
beforeEach - step 2
testFunc - step 1
testFunc - step 3
beforeEach - after testFunc - step 3
testFunc - step 2
Last trace

预期输出

[launcher] Running 1 instances of WebDriver
beforeEach - step 1
beforeEach - step 2
testFunc - step 1
testFunc - step 2 // <------  This is within the promise resolve
testFunc - step 3
beforeEach - after testFunc - step 3
Last trace

推荐答案

我想这会得到你想要的输出:

I think this will get the output you want:

describe('testAsync', function() {

  beforeEach(function() {
    console.log('beforeEach - step 1 ');

    // `get` implicitly registers a promise with the control flow
    browser.get("https://angularjs.org/");

    console.log('beforeEach - step 2 '); // runs "before" get above returns!

    testFunc().then(function() {
       // use a then to explicitly chain a dependency off a promise
       console.log('beforeEach - after testFunc - step 3');
    })

    protractor.promise.controlFlow().execute(function() {
       console.log('beforeEach - after testFunc, via controlFlow - step 4');
    });

    console.log('beforeEach - end of beforeEach - everything registered, nothing done');
  });

  var testFunc = function(){

    console.log("testFunc - step 1")

    // return browser wait promise to caller
    // `wait` also implicitly registers with the control flow
    return browser.wait(function() {
      return element(by.id('twitter-widget-1')).isPresent()
        .then(function (isPresent) {
          console.log("testFunc - step 2")
          return true; // tell wait its done by resolving then promise->element promise->wait
      });
    });
  }

  it('test after BeforeEach', function() {
    console.log("Last trace")
  });

});

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