Angular 6单元测试:afterAll \ nReferenceError中引发了错误:找不到变量:$ [英] Angular 6 Unit Tests: An error was thrown in afterAll\nReferenceError: Can't find variable: $ thrown

问题描述

在运行我的单元测试时，即使它们通过了，在所有测试运行结束时，我也会经常遇到以下错误.

When running my unit tests, from time to time, even if they pass, at the end of all the tests running, I will get the following error.

在运行PhantomJS的Jenkins CI构建上:

On my Jenkins CI build running PhantomJS:

.PhantomJS 2.1.1 (Linux 0.0.0) ERROR
  {
    "message": "An error was thrown in afterAll\nReferenceError: Can't find variable: $ thrown",
    "str": "An error was thrown in afterAll\nReferenceError: Can't find variable: $ thrown"
  }

或在Chrome上

Chrome 67.0.3396 (Windows 7 0.0.0) ERROR
  {
    "message": "An error was thrown in afterAll\n[object ErrorEvent] thrown",
    "str": "An error was thrown in afterAll\n[object ErrorEvent] thrown"
  }

我也有非常不可靠的测试，有时它们不会成功，而有时相同的测试却失败，因此我不做任何更改，所以我知道发生了一些奇怪的事情.

I also have really unreliable tests, without changing anything some times they would succeed and other times the same tests would fail, so I knew something weird was going on.

推荐答案

我的问题是由于设置测试的一种非常愚蠢的方式，我的测试中出现了竞争状况，但无论如何我还是希望在此处进行记录，因为我很难在互联网上找到我的问题的答案.

My issue was that I had a race condition in my tests due to a very stupid way of setting up my tests, but I wanted to document it here anyways because I struggled to find the answer to my issue on the internet.

我以某种方式完成的工作是声明两个beforeEach函数来设置测试，而两个函数之一是异步的，因此我遇到了竞争状况，有时它们会出现故障并失败.

What I had somehow done was to declare two beforeEach functions to setup my test, and one of the two was asynchronous, so I had a race condition where sometimes they ran out of order and failed.

这是我的测试的样子:

beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [ HomeComponent ]
    })
    .compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(HomeComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

因此，为解决此问题，我将所有设置整合为一个，同步beforeEach.

So to resolve this I put all the setup into one, synchronous beforeEach.

  beforeEach(() => {
    TestBed.configureTestingModule({
      declarations: [HomeComponent]
    }).compileComponents();
    fixture = TestBed.createComponent(HomeComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

我花了太多时间试图解决这个问题，所以我把它放在这里以拯救别人.

I wasted too much time trying to figure this out, so I'm putting it here to save someone else.

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