Angular Karma Jasmine Error: Illegal state: Could

问题:

I'm developing a github repository (with angular 7 and angular-cli), and I have some tests with Karma and Jasmine working in the master branch.

Now I'm trying to add lazy loading feature, the thing is, that the tests that before passed, now they do not. It's funny because only the tests from the lazy loading module are failing...

Here is the code and the error:

import {async, TestBed} from '@angular/core/testing';
import {APP_BASE_HREF} from '@angular/common';
import {AppModule} from '../../app.module';
import {HeroDetailComponent} from './hero-detail.component';

describe('HeroDetailComponent', () => {
  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [AppModule
      ],
      providers: [
        {provide: APP_BASE_HREF, useValue: '/'}
      ],
    }).compileComponents();
  }));

  it('should create hero detail component', (() => {
    const fixture = TestBed.createComponent(HeroDetailComponent);
    const component = fixture.debugElement.componentInstance;
    expect(component).toBeTruthy();
  }));
});

The error is this:

Chrome 58.0.3029 (Mac OS X 10.12.6) HeroDetailComponent should create hero detail component FAILED
    Error: Illegal state: Could not load the summary for directive HeroDetailComponent.
        at syntaxError Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/~/@angular/compiler/@angular/compiler.es5.js:1690:22)
        at CompileMetadataResolver.getDirectiveSummary Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/~/@angular/compiler/@angular/compiler.es5.js:15272:1)
        at JitCompiler.getComponentFactory Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/~/@angular/compiler/@angular/compiler.es5.js:26733:26)
        at TestingCompilerImpl.getComponentFactory Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/~/@angular/compiler/@angular/compiler/testing.es5.js:484:1)
        at TestBed.createComponent Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/~/@angular/core/@angular/core/testing.es5.js:874:1)
        at Function.TestBed.createComponent Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/~/@angular/core/@angular/core/testing.es5.js:652:1)
        at UserContext.it Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/src/app/heroes/hero-detail/hero-detail.component.spec.ts:18:29)
        at ZoneDelegate.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneDelegate.invoke Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/~/zone.js/dist/zone.js:391:1)
        at ProxyZoneSpec.onInvoke Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/~/zone.js/dist/proxy.js:79:1)
        at ZoneDelegate.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneDelegate.invoke Users/ismael.ramos.silvan/WebstormProjects/angular4-example-app/~/zone.js/dist/zone.js:390:1)

You can see the entire project, for more details if you need it.

UPDATE: added declaration like this:

beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [
        AppModule
      ],
      declarations: [HeroDetailComponent],
      providers: [
        {provide: APP_BASE_HREF, useValue: '/'}
      ],
    }).compileComponents();
  }));

Now, new errors appears:

The pipe 'translate' could not be found ("<h1 class="section-title">{{[ERROR ->]'heroDetail' | translate}}</h1>
    <md-progress-spinner *ngIf="!hero"
                         class="progre"): ng:///DynamicTestModule/HeroDetailComponent.html@0:28
    Can't bind to 'color' since it isn't a known property of 'md-progress-spinner'.

And more... it's like all directives and components from angular material, and the pipe translate from ngx-translate/core do not appear to be included...

UPDATED: FINAL SOLUTION

The problem was that HeroesModule was not been imported anywhere. This works, because HeroesModule declares HeroDetailComponent, which was the initial problem:

import {async, TestBed} from '@angular/core/testing';
import {APP_BASE_HREF} from '@angular/common';
import {AppModule} from '../../app.module';
import {HeroDetailComponent} from './hero-detail.component';
import {HeroesModule} from '../heroes.module';

describe('HeroDetailComponent', () => {
  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [
        AppModule,
        HeroesModule
      ],
      providers: [
        {provide: APP_BASE_HREF, useValue: '/'}
      ],
    }).compileComponents();
  }));

  it('should create hero detail component', (() => {
    const fixture = TestBed.createComponent(HeroDetailComponent);
    const component = fixture.debugElement.componentInstance;
    expect(component).toBeTruthy();
  }));
});

回答1:

You passed HeroDetailComponent to TestBed.createComponent() without declaring the component first:

TestBed.configureTestingModule({
  imports: [AppModule,
     CommonModule,
     FormsModule,
     SharedModule,
     HeroRoutingModule,
     ReactiveFormsModule
  ],
  providers: [
    {provide: APP_BASE_HREF, useValue: '/'}
  ],
  declarations: [HeroDetailComponent]
}).compileComponents();

Hope it helps.

---

Update for following errors in your test: Added some more imports (just take your HeroModule as a blueprint because that's basically what you want to import and provide).

回答2:

You're missing the declarations, you need to add the class being tested into the declarations.

declarations: [component]

回答3:

This type of error raised due to missing adding component in declarations and services in provider of TestBed configuration.

beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [RouterTestingModule.withRoutes([
        { path: 'home', component: DummyComponent },
        { path: 'patients/find', component: DummyComponent }
      ])],
      declarations: [RoutingComponent, DummyComponent,BreadcrumbComponent],
      providers : [BreadCrumbService]
    });

回答4:

My coworker and I had this issue but the fix was way different than anything else on the internet.

We are using Visual Studio Code and the folder names are case insensitive. Because of that, we asked everyone to use a lowercase naming convention but eventually an uppercase name got into source control. We renamed it, in a roundabout way, and everything was fine.

A month later, my coworker started getting a specific unit test to break with this error message. Only his computer was breaking on that test. We literally commented out all the code that could possible be effecting the test and we still got the error. Finally, I globally searched for the class and we realized that the folder name had reverted back to the uppercase name. We renamed it back to a lowercase name, with no pending changes recognized might I add..., and the test worked.

Let that be a lesson to follow style guides. :)

For clarity, the fix was similar to changing the folder name FOO to foo.

回答5:

you must import the component HeroDetailComponent in the right way. Notice that even case of letters is matter in paths. i.e ('@angular/forms' is correct, BUT'@angular/Forms' is not.

回答6:

For those who are still having issues with this - I read a separate github issue that discussed changes the Angular team made to the beforeEach callback function.

Here is what I did:

beforeAll(async(() => {
    TestBed.configureTestingModule({
        declarations: [BannerNotificationComponent]
    }).compileComponents()

    fixture = TestBed.createComponent(BannerNotificationComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
}));

Using beforeAll fixes the issue. Hope this helps others as it took me about a day to get this resolve this obscure bug.

回答7:

If you want to test a component without compiling it then you can by declaring it as a provider:

beforeEach(() => {
  TestBed.configureTestingModule({
    // provide the component-under-test and dependent service
    providers: [
      WelcomeComponent,
      { provide: UserService, useClass: MockUserService }
    ]
  });
  // inject both the component and the dependent service.
  comp = TestBed.get(WelcomeComponent);
  userService = TestBed.get(UserService);
});

See: https://angular.io/guide/testing#component-test-basics