无法在Angular Unit测试中为反应式表单设置Formgroup的“valid”属性

import { ReactiveFormsModule, FormsModule } from '@angular/forms';

beforeEach(async(() => {
  TestBed.configureTestingModule({
    imports: [ReactiveFormsModule, FormsModule],
    declarations: [YourComponent],
  }).compileComponents();
}));

it('should set "valid" property of the form group', () => {
  const formGroup = new FormGroup({
    name: new FormControl('John', Validators.required),
    email: new FormControl('john@example.com', Validators.email),
  });

  expect(formGroup.valid).toBeTruthy();
});