javascript - 测试 Angular 表单提交

Question

我正在测试一个 Angular 应用程序，尤其是这个 HTML 输入:

<form  name="editForm" role="form" novalidate (ngSubmit)="save()" #editForm="ngForm">
     <input type="text" name="nombre" id="field_nombre"
    	                [(ngModel)]="paciente.nombre" required/>
(etc. f.e. button on submit...)

这是我的组件:

imports....


export class PacienteDialogComponent implements OnInit {
    
    paciente: Paciente;
    
    ....
    
       save() {
        this.isSaving = true;
        if (this.paciente.id !== undefined) {
            this.subscribeToSaveResponse(
                this.pacienteService.update(this.paciente));
        } else {
            this.subscribeToSaveResponse(
                this.pacienteService.create(this.paciente));
        }
    }
}

这是我的病人.model.ts

export class Paciente implements BaseEntity {
    constructor(
        public id?: number,
        public nombre?: string,
        public sexo?: Sexo,
        
        .....

我想测试表单，这意味着在提交时它实际上是在调用 save() 函数。我的测试中有这个:

describe('Paciente Management Dialog Component', () => {
        let comp: PacienteDialogComponent;
        let fixture: ComponentFixture<PacienteDialogComponent>;
        let debugElement: DebugElement; //create a debgElement for testing

        beforeEach(async(() => {
            TestBed.configureTestingModule({
                imports: [OncosupTestModule,
                    OncosupSharedModule,
                    BrowserModule,
                    FormsModule,
                  
                ],
                declarations:...
                ],
                providers: [
                    ...
            })
            .compileComponents();
        }));

  beforeEach(() => {
            fixture = TestBed.createComponent(PacienteDialogComponent);
            comp = fixture.componentInstance;
            debugElement = fixture.debugElement;
        });
                //a default generated test which controls if the save method really saves a new patient with its name, id, sex, etc.
        it('Should call create service on save for new entity',
           inject([],
               fakeAsync(() => {
                   // GIVEN
                   const entity = new Paciente();
                   spyOn(service, 'create').and.returnValue(Observable.of(new HttpResponse({body: entity})));
                   comp.paciente = entity;
                   // WHEN
                   comp.save();
                   tick(); // simulate async

                   // THEN
                   expect(service.create).toHaveBeenCalledWith(entity);
                   expect(comp.isSaving).toEqual(false);
                   expect(mockEventManager.broadcastSpy).toHaveBeenCalledWith({ name: 'pacienteListModification', content: 'OK'});
                   expect(mockActiveModal.dismissSpy).toHaveBeenCalled();
               })
           )
       );
// And teh second thing I want to test is if ngSubmit is really calling the save() function


           it ('should call the onSubmit method', async(() => {
            //fixture.detectChanges();
            spyOn(comp,'save');
            var1 = debugElement.query(By.css('button')).nativeElement;
            console.log('print button ' + var1);
            var1.click();
            expect(comp.save).toHaveBeenCalledTimes(0);//verify...
            }));

//And also if isSaving is set to true


 it ('should set isSaving to true', async(() => {
           comp.save();
            expect(comp.isSaving).toBeTruthy();
         
           }));





         
        
        

1.现在我有这些问题:第一个测试是默认生成的，不是我写的。在这一行中 constentity = new Paciente(); 我应该调用 Paciente 的参数吗？比如 id、性别、姓名，或者默认不带参数。第一个测试的目的是检查 save() 函数是否真的保存了患者及其数据，如 ID、性别等。

2.对于第二个测试，我在 Angular 教程中读到: HaveBennCalled(0) 是测试此 spy 是否被调用以及调用次数的正确方法。但无论如何，它确实测试按钮是否调用函数 save()。我认为它只检查按钮之前是否没有被调用过，而不是检查现在是否在保存函数中调用过。

3.这 3 个测试对于表单提交来说是否足够且完整？

Answer 1

根据我的评论，以下是如何测试表单是否正确提交。

假设您有一个界面Patient:

export interface Patient {
  id: number;
  name: string;
}

在您的组件中，您有一个表单，并通过 submit() 提交它:

submit() {
  this.patientService.savePatient(this.patient).subscribe(result => {
    console.log('Patient created');
  });
}

现在您的服务进行 HTTP 调用并检查字段是否正常:

savePatient(patient: Patient): Observable<any> {
  if (typeof patient.id !== number) { return Observable.throw('ID is not a number'); }
  if (typeof patient.name !== string) { return Observable.throw('Name is not a string'); }

  return this.http.post<any>(this.url, patient);
}

那么你的测试应该如下所示。一、组件:

it('Should call the service to save the patient in DB', () => {
  // Spy on service call
  // Expect spy to have been called
});

it('Should log a message on success', () => {
  // Spy on console log
  // Expect console log to have been called with a string
});

您还可以测试错误是否被正确处理，是否有错误代码等。

现已投入使用:

it('Should throw an error if the ID is not a number', () => {
  // Mock a patient with a string ID
  // Expect an error to be thrown
});

// Same thing for the name, you get the idea

it('Should make an HTTP call with a valid patient', () => {
  // Spy on the HttpTestingController
  // Expect the correct endpoint to have been called, with the patient as the payload
});

这些测试的总体思路是涵盖任何可能发生的情况。这将使您能够防止副作用:例如，如果有一天您决定将 ID 传递给字符串，单元测试将失败并告诉您

You expect me to send a string but I pass only with a number

这就是单元测试的目的。