测试 – 间歇性错误：’失败：选择器“#root0”与任何元素都不匹配

Linux 2020-08-11
我正在使用Angular2 beta版本构建一个应用程序,当我运行我的测试用例时,我随机得到错误：

The selector “#root0” did not match any elements’ error.

测试代码：

@Component({
  template: '',directives: [GroupBox,GroupBoxHeader]
})
class TestComponent {
}

describe('group-box control',() => {

  it('should show the title',injectAsync([TestComponentBuilder],(tcb) => {
    return tcb.overrideTemplate(TestComponent,'<group-box><group-box-header>Title Content</group-box-header></group-box>')
      .createAsync(TestComponent).then( (fixture) => {
        fixture.detectChanges();
        let compiled = fixture.debugElement.nativeElement;
        expect(compiled).toContainText('Title Content');
    });
  }));

  it('should show the body','<group-box><group-box-header>Title Content</group-box-header>Body Content</group-box>')
      .createAsync(TestComponent).then( (fixture) => {
        fixture.detectChanges();
        let compiled = fixture.debugElement.nativeElement;
        expect(compiled).toContainText('Body Content');
    });
  }));
});

我按照https://github.com/juliemr/ng2-test-seed的指导方针使用Karma和Jasmine

以下存储库重现错误：https://github.com/cangosta/ng2_testing_controls

堆栈跟踪：

14 01 2016 11:40:32.073:INFO [karma]: Karma v0.13.19 server started at 07002
14 01 2016 11:40:32.078:INFO [launcher]: Starting browser Chrome
14 01 2016 11:40:32.669:INFO [Chrome 47.0.2526 (Windows 8.1 0.0.0)]: Connected on socket /#9hKZqsNbKFPfYWzIAAAA with id 50428936
Chrome 47.0.2526 (Windows 8.1 0.0.0) group-box control should show the body FAILED
Failed: The selector “#root0” did not match any elements
Error: The selector “#root0” did not match any elements
at new BaseException (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2.dev.js:8080:21)
at DomRenderer_.createRootHostView (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2.dev.js:15248:15)
at AppViewManager_.createRootHostView (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2.dev.js:11265:52)
at C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2.dev.js:14531:46
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:138:17)
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2544:30)
at zoneBoundFn (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:111:19)
at lib$es6$promise$$internal$$tryCatch (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1511:16)
at lib$es6$promise$$internal$$invokeCallback (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1523:17)
at lib$es6$promise$$internal$$publish (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1494:11)
at C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:243:5
at microtask (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2557:15)
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:138:17)
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2544:30)
at zoneBoundFn (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:111:19)
at lib$es6$promise$asap$$flush (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1305:9)
Failed: Cannot read property ‘hostView’ of undefined
TypeError: Cannot read property ‘hostView’ of undefined
at new ComponentFixture_ (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2047:97)
at C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2145:16
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:138:17)
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2544:30)
at zoneBoundFn (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:111:19)
at lib$es6$promise$$internal$$tryCatch (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1511:16)
at lib$es6$promise$$internal$$invokeCallback (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1523:17)
at lib$es6$promise$$internal$$publish (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1494:11)
at C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:243:5
at microtask (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2557:15)
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:138:17)
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2544:30)
at zoneBoundFn (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:111:19)
at lib$es6$promise$asap$$flush (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1305:9)
Failed: Cannot read property ‘detectChanges’ of undefined
TypeError: Cannot read property ‘detectChanges’ of undefined
at C:/Projectos/Fontes/Stratus-HTML/build/test/infrastructure/controls/group-box.test.js:52:20
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:138:17)
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2544:30)
at zoneBoundFn (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:111:19)
at lib$es6$promise$$internal$$tryCatch (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1511:16)
at lib$es6$promise$$internal$$invokeCallback (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1523:17)
at lib$es6$promise$$internal$$publish (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1494:11)
at C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:243:5
at microtask (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2557:15)
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:138:17)
at Zone.run (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/testing.dev.js:2544:30)
at zoneBoundFn (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:111:19)
at lib$es6$promise$asap$$flush (C:/Projectos/Fontes/Stratus-HTML/build/assets/js/angular2-polyfills.js:1305:9)
Chrome 47.0.2526 (Windows 8.1 0.0.0): Executed 59 of 60 (1 FAILED) (skipped 1) (0.519 secs / 0.51 secs)
[11:40:33] ‘test’ errored after 2.01 s
[11:40:33] Error: 1
at formatError (C:\Users\LSANTOS\AppData\Roaming\npm\node_modules\gulp\bin\gulp.js:169:10)
at Gulp. (C:\Users\LSANTOS\AppData\Roaming\npm\node_modules\gulp\bin\gulp.js:195:15)
at emitOne (events.js:77:13)
at Gulp.emit (events.js:169:7)
at Gulp.Orchestrator._emitTaskDone (C:\Projectos\Fontes\Stratus-HTML\node_modules\orchestrator\index.js:264:8)
at C:\Projectos\Fontes\Stratus-HTML\node_modules\orchestrator\index.js:275:23
at finish (C:\Projectos\Fontes\Stratus-HTML\node_modules\orchestrator\lib\runTask.js:21:8)
at cb (C:\Projectos\Fontes\Stratus-HTML\node_modules\orchestrator\lib\runTask.js:29:3)
at removeAllListeners (C:\Projectos\Fontes\Stratus-HTML\node_modules\karma\lib\server.js:333:7)
at Server. (C:\Projectos\Fontes\Stratus-HTML\node_modules\karma\lib\server.js:344:9)
at Server.g (events.js:260:16)
at emitNone (events.js:72:20)
at Server.emit (events.js:166:7)
at emitCloseNT (net.js:1518:8)
at doNTCallback1 (node.js:418:9)
at process._tickCallback (node.js:340:17)

解决方法

这在Angular 2.0.0-beta.3中得到修复

有关详细信息,请参见https://github.com/angular/angular/issues/6483#issuecomment-179557485

Basically,what I had to do:

  • Manually add typings for jasmine with tsd install jasmine -so and add ///<reference... in the test files;
  • Add this in my imports:
import {setBaseTestProviders} from 'angular2/testing';

import {
  TEST_BROWSER_PLATFORM_PROVIDERS,TEST_BROWSER_APPLICATION_PROVIDERS
} from 'angular2/platform/testing/browser';

Add this before my Component tests:

setBaseTestProviders(TEST_BROWSER_PLATFORM_PROVIDERS,TEST_BROWSER_APPLICATION_PROVIDERS);

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