如何以角度对剪贴板副本进行单元测试？

Question

如何监视clipboard.copy方法？为了

const clipboard = TestBed.inject(Clipboard);
spyOn(clipboard, 'copy').and.returnValue(true);

我收到警告

Argument of type '"copy"' is not assignable to parameter of type 'keyof Clipboard'.

我还尝试将其添加到导入和声明中：

这是CopyToClipboardHost

class CopyToClipboardHost {
  public content = '';
  public attempts = 1;
  public copied = jasmine.createSpy('copied spy');
}

Answer 1

我不知道为什么它在您的案例中不起作用，但我设法创建简单的测试案例并且它工作正常：

import {Component} from '@angular/core';
import {ComponentFixture, TestBed, waitForAsync} from '@angular/core/testing';
import {Clipboard} from '@angular/cdk/clipboard';
import createSpyObj = jasmine.createSpyObj;

@Component({
  selector: 'app-root',
  template: ''
})
export class SampleComponent {
  constructor(private clipboard: Clipboard) {
  }

  copySomething(): void {
    this.clipboard.copy('test');
  }
}

describe('SampleComponent', () => {
  let fixture: ComponentFixture<SampleComponent>;
  let component: SampleComponent;
  const clipboardSpy = createSpyObj<Clipboard>('Clipboard', ['copy']);

  beforeEach(waitForAsync(() => {
    TestBed.configureTestingModule({
      declarations: [SampleComponent],
      providers: [{provide: Clipboard, useValue: clipboardSpy}]
    }).compileComponents();
  }));

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

  it('should call clipboard copy', () => {
    component.copySomething();

    expect(clipboardSpy.copy).toHaveBeenCalledWith('test');
  });
});

需要注意的一件事 - 不要导入外部模块，因为TestingModule您只想测试您的组件，而不是对所需的依赖项进行模拟/监视。