Angular 测试和 ngModel

Question

我正在用 Angular 编写我的第一个组件测试，但我在使 ngModel 绑定工作时遇到了一些困难。这是我的测试模块定义：

beforeEach(async(() => {
    TestBed.configureTestingModule({
      declarations: [
        LdapLoginComponent,
      ],
      imports: [
        CommonModule,
        FormsModule,
        NoopAnimationsModule,
        MatInputModule,
        MatFormFieldModule,
        RouterTestingModule,
      ],
      providers: [
        {
          provide: AuthorizationService,
          useValue: { login() {} },
        },
      ]
    }).compileComponents();
  }));

这是我的测试用例：

it('should bind form fields with class', fakeAsync(() => {
    // Given
    const username = 'username';
    const password = 'password';
    const usernameField = de.query(By.css('input[name=username]')).nativeElement;
    const passwordField = de.query(By.css('input[name=password]')).nativeElement;

    // When
    usernameField.value = username;
    passwordField.value = password;
    usernameField.dispatchEvent(new Event('input'));
    passwordField.dispatchEvent(new Event('input'));
    tick();
    fixture.detectChanges();

    // Then
    expect(comp.username).toEqual(username);
    expect(comp.password).toEqual(password);
  }));

我的组件class:

export class LdapLoginComponent {

  username: string;
  password: string;
  errorMessage: string;
  submitDisabled = false;

  constructor(
    private authorizationService: AuthorizationService,
    private router: Router,
  ) {
  }

  login(): void {
    delete this.errorMessage;
    this.submitDisabled = true;
    this.authorizationService.login(AuthorizationProvider.LDAP, this.username, this.password)
      .subscribe(
        () => {
          this.router.navigate(['/']);
        },
        (err: Error) => {
          this.errorMessage = err.message;
          this.submitDisabled = false;
        },
      );
  }

}

我的组件模板：

<form class="form-container" (submit)="login()">
  <mat-form-field color="warn">
    <input
    matInput
    type="text"
    name="username"
    placeholder="Insert your username"
    [(ngModel)]="username"
    required
    i18n-placeholder="@@input.placeholder.username">
  </mat-form-field>
  <mat-form-field color="warn">
    <input
      matInput
      type="password"
      name="password"
      placeholder="Insert your password"
      [(ngModel)]="password"
      required
      i18n-placeholder="@@input.placeholder.password">
  </mat-form-field>
  <button
    mat-raised-button
    type="submit"
    color="warn"
    [disabled]="submitDisabled"
    i18n="@@input.submit">Submit</button>
</form>
<article>{{errorMessage}}</article>

我正在更改测试中用户名和密码字段的值，我希望我的 class 的用户名和密码字段也相应更新。如果我在浏览器中手动测试一切正常，但在测试中却不行。

有什么想法吗？

谢谢。

Answer 1

问题是您实际上并没有在调用 dispatchEvent 之前设置输入字段的值。您正在直接设置组件属性。

comp.username = username;
usernameField.dispatchEvent(new Event('input'));

应该是

let usernameFieldElement = usernameField.nativeElement;
usernameFieldElement.value = username;
usernameField.dispatchEvent(new Event('input'));

密码也一样。

另一件事是您同时测试三件事，将文本输入到输入区域，单击按钮运行登录和登录功能本身。我建议将它们分成三个断言。

如上设置字段并检查数据绑定。
单击按钮并监视登录函数以检查它是否已被调用。
设置实际的组件属性并直接调用 logon() 并检查您的 navigateSpy 是否已正确调用。

这样，如果出现问题，您将能够更轻松地找到它。

Answer 2

看起来像垫输入字段，我们需要在更改输入之前执行 focus()：

it('should bind form fields with class', fakeAsync(() => {
    // Given
    const username = 'username';
    const password = 'password';
    const usernameField = de.query(By.css('input[name=username]')).nativeElement;
    const passwordField = de.query(By.css('input[name=password]')).nativeElement;

    usernameField.focus();
    passwordField.focus();

    // When
    usernameField.value = username;
    passwordField.value = password;
    usernameField.dispatchEvent(new Event('input'));
    passwordField.dispatchEvent(new Event('input'));
    tick();
    fixture.detectChanges();

    // Then
    expect(comp.username).toEqual(username);
    expect(comp.password).toEqual(password);
}));

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