模拟函数调用时如何检查发射值

Question

我正在使用 https://testing-library.com/ 来测试我的 angular 应用程序。

这是我的组件函数：

onCreateFormSubmit() {

    if (this.createForm.valid && this.crud.isCreate) {
        this.ssCreated.emit(created); //emits the data, needs to test
    }

}

测试规格：

test('Testing add Subsystem operation', async () => {

    const data = {
        Id: 2,
        Name: 'subsystem2',
        IsDeletePossible: true,
        CreatedBy: '',
        CreatedDate: new Date(),
        UpdatedBy: '',
        UpdatedDate: new Date(),
        UpdatedByName: 'test value',
        CreatedByName: ''
    } as ModelSubSystem;

    const ssCreatedEmit = jest.fn();

    const component = await render(SubSystemComponent, {
        schemas: [CUSTOM_ELEMENTS_SCHEMA],
        imports: [
            HttpClientTestingModule,
            FormsModule,
            ReactiveFormsModule,
            StoreModule.forRoot({}, { runtimeChecks: { strictStateImmutability: true, strictActionImmutability: true } }),
            StoreModule.forFeature('pfservice', reducer),
            EffectsModule.forRoot([]),
            EffectsModule.forFeature([EffectsSubSystem])
        ],
        componentProperties: {
            onCreateFormSubmit: jest.fn(),
            ssCreated: {
                emit: ssCreatedEmit
            } as any,
        }

    });

    const componentInstance = component.fixture.componentInstance;


    /*
     *   Testing the form by DOM.
     */

    const createButton = component.getByTestId('btn-addRow');
    component.click(createButton);
    component.fixture.detectChanges();
    // status changes because of click on button
    expect(componentInstance.crud.isCreate).toBeTruthy();

    component.fixture.detectChanges();
    // onclick submit should not called, becasue of empty input

    component.input(component.getByTestId('form-create-name-field-0'), {
        target: {
            value: data.Id
        }
    });

    component.input(component.getByTestId('form-create-name-field-1'), {
        target: {
            value: data.Name
        }
    });


    component.blur(component.getByTestId('form-create-name-field-1'));

    component.input(component.getByTestId('form-create-name-field-2'), {
        target: {
            value: data.UpdatedByName
        }
    });

    const submit = component.getAllByTestId('form-create-btn')[0];

    component.click(submit);

    component.fixture.detectChanges();
    const name = componentInstance.createForm.controls['Name'];
    const updatedByName = componentInstance.createForm.controls['UpdatedByName'];
    expect(name.value).toEqual(data.Name);
    expect(name.errors).toBeFalsy();
    expect(updatedByName.value).toEqual(data.UpdatedByName);
    expect(componentInstance.onCreateFormSubmit).toHaveBeenCalledTimes(1); //works.

    expect(componentInstance.ssCreated).toHaveBeenCalledWith(data); // not works throw error

});

出现错误：

Matcher error: received value must be a mock or spy function

如何用我设置的数据检查我的发射数据？

提前致谢。

Answer 1

我们正在 spy 使用 emit 函数。因此，你应该这样做：expect(componentInstance.ssCreated.emit).toHaveBeenCalledWith(data)

示例见https://github.com/testing-library/angular-testing-library/blob/master/src/app/examples/02-input-output.spec.ts

模拟函数调用时如何检查发射值

How to check the emit value when it's called by mock function

angular8

angular-test

angular-testing-library