Question

所以我有一个输入的指令：

@Directive({
    selector: '[my-directive]'
})
export class MyDirective {

    @Input('some-input')
    public someInput: string;
}

如您所见，输入应为string值。现在，我想为此指令编写一个测试，我想测试输入是否满足string类型：

describe('MyDirective', () => {

    let fixture: ComponentFixture<DummyComponent>;
    let dummy: DummyComponent;
    let directive: DebugElement;

    beforeEach(async(() => {

        TestBed
            .configureTestingModule({
                imports: [
                    MyModule.forRoot()
                ],
                declarations: [
                    DummyComponent
                ]
            })
            .compileComponents();

        fixture = TestBed.createComponent(DummyComponent);
        dummy = fixture.componentInstance;
        directive = fixture.debugElement.query(By.directive(MyDirective));

        fixture.detectChanges();
    }));

    it('should satisfy only a string input and error on other inputs', () => {
        // How to test?
    });
});

@Component({
    selector: 'dummy',
    template: `
        <div my-directive [some-input]="'just-a-string-value'"></div>
    `
})
export class DummyComponent implements OnInit {
}

如何测试@Input值是否属于正确类型？

Answer 1

所以有点晚了，但是我来这里寻找同样的问题，所以我将发布解决方案。这是我测试指令输入（或其他属性）值的方法：

describe('MyDirective', () => {

    let fixture: ComponentFixture<DummyComponent>;
    let dummy: DummyComponent;
    let directive: DebugElement;

    beforeEach(async(() => {

        TestBed
            .configureTestingModule({
                imports: [
                    MyModule.forRoot()
                ],
                declarations: [
                    DummyComponent
                ]
            })
            .compileComponents();

        fixture = TestBed.createComponent(DummyComponent);
        dummy = fixture.componentInstance;
        directive = fixture.debugElement.query(By.directive(MyDirective));

        fixture.detectChanges();
    }));

    it('should satisfy only a string input and error on other inputs', () => {
        
        // needed so template is processed, inputs are updated
        fixture.detectChanges();
        
        // since we declared a ViewChild on the directive, we can access
        // and test directive properties values
        expect(component.directive.someInput).toEqual('just-a-string-value');
        // to test the input type :
        expect(component.directive.someInput).toEqual(Jasmine.any(String));
        // I thought TypeScript would complain when providing a wrong type input to a directive, but no...so I guess I'll test the input type too !
    });
});

@Component({
    selector: 'dummy',
    template: `
        <div my-directive [some-input]="'just-a-string-value'"></div>
    `
})
export class DummyComponent implements OnInit {

  // add a reference to the directive in template
  // so in your component you can access : this.directive, this.directive.someInput
  ViewChild(MyDirective) directive: MyDirective;
}

因此：修改测试组件以在指令实例上保留引用，然后通过component.directive。[property-name]访问指令属性。顺便说一句，如果您为指令属性提供默认值（可以通过在模板中提供值来覆盖默认值），则可以在调用夹具.detectChanges（）之前对其进行测试。

Answer 2

https://angular.io/guide/testing#test-a-component-with-inputs-and-outputs

具有输入和输出的组件通常出现在视图中   主机组件的模板。主机使用属性绑定进行设置   input属性和事件绑定来监听由引发的事件   输出属性。

测试目标是验证此类绑定是否按预期工作。该   测试应设置输入值并监听输出事件。

代码示例在链接中。

Angular 2/4 - 如何测试指令@Input值？

2 个答案: