所以我有一个指令,需要输入：
@Directive({
selector: '[my-directive]'
})
export class MyDirective {
@Input('some-input')
public someInput: string;
}
如您所见,输入应为字符串值.现在,我想为这个指令编写测试,我想测试输入是否满足字符串类型：
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？
解决方法
所以有点晚了,但我来到这里寻找同样的问题,所以我会发布我的解决方案.这是我测试指令输入(或其他属性)值所做的：
describe('MyDirective',() => {
// 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存引用,然后通过component.directive.[property-name]访问指令属性.顺便提一下,如果为指令属性提供默认值(可以通过在模板中提供值来覆盖),则可以在调用fixture.detectChanges()之前测试它们.
