Angular2 Testing “Cannot find name 'HTMLElement'”

Question

I'm trying to introduce testing into my existing project, but I keep running into the same error, which I think is prohibiting me from running the tests. The error I get is

ERROR in .../src/app/dashboard.component.spec.ts (15,13): Cannot find name 'HTMLElement'.)

Chrome 57.0.2987 (Mac OS X 10.12.3): Executed 4 of 4 SUCCESS (7.24 secs / 6.55 secs)

My dashboard.component.spec.ts looks like this:

import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { By } from '@angular/platform-browser';
import { DebugElement } from '@angular/core';

import { DashboardComponent } from './dashboard.component';
import { ExchangeService } from './exchange.service';

describe('DashboardComponent (templateUrl)', () => {

    let comp: DashboardComponent;
    let fixture: ComponentFixture<DashboardComponent>;

    let spy: jasmine.Spy;
    let de: DebugElement;
    let el: HTMLElement; // how does this work...?
    let exchangeService: ExchangeService; // the actual injected service

    const testExchange = 'New York Stock Exchange';

    beforeEach(async(() => {
        TestBed.configureTestingModule({
            declarations: [ DashboardComponent ],
            providers: [ ExchangeService ],
        })
        .compileComponents();
    }))


    beforeEach(() => {

        fixture = TestBed.createComponent(DashboardComponent);
        comp = fixture.componentInstance; // DashboardComponent test componentInstance

        // ClockService actually injected into the component
        exchangeService = fixture.debugElement.injector.get(ExchangeService);

        // Setup spy on the `getExchanges` method
        spy = spyOn(exchangeService, 'getExchanges')
            .and.returnValue(Promise.resolve(testExchange));
        // query for the title <h1> by CSS element selector

        de = fixture.debugElement.query(By.css('.exchange'));
        el = de.nativeElement;
    });

    it('should not show exchange before OnInit', () => {
        expect(el.textContent).toBe('', 'nothing displayed');
        expect(spy.calls.any()).toBe(false, 'getExchanges not yet called');
    });

    it('true is true', () => expect(false).toBe(true));
});

I have searched all around for that error message, but I can't seem to find it anywhere. Also, the last test should fail, but I don't think it even compiles due to this error. Any clues as to what is wrong? I initially thought it would be an import that I was missing, but I can't see anyone else importing HTMLElements. Thanks!

Edit: My tsconfig.json looks like this:

{
  "compileOnSave": false,
  "compilerOptions": {
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "target": "es5",
    "lib": [
      "es6",
      "dom",
      "es2015.iterable"
    ]
  }
}

Edit 2: I actually had to Ctrl+C, and restart the test for it to compile correctly (I thought it would do it upon change of files, but it didn't). Thank you!

Answer 1

在测试项目的tsconfig.json ，您应该将dom库添加到lib数组中：

"lib": ["es6", "dom", "es2015.iterable"],

Answer 2

I also typed HTMLElement wrong, ex. I did HtmlElement . hope this helps.

Answer 3

I had the same problem when continuous testing but not with a single run. The test would compile on the initial run but when I changed any code then the compilation would halt with the

Cannot find name 'HTMLElement'

error message and I had to do a Ctr+C and restart.
Changing tsconfig.spec.json to

"lib": ["es6", "dom"],

as suggested by PierreDuc cured the problem and my test suites run in continuous mode.