[英]Mocking a Subject property of mocked service to be subscribed in the Angular unit test
In my Angular unit testing my mocked service has two properties:在我的 Angular 单元测试中,我的模拟服务有两个属性:
public messageChange: Subject<ChatMessage> = new Subject<ChatMessage>();
public gameChange: Subject<GameState> = new Subject<GameState>();
And in my SUT I use them in my constructor:在我的 SUT 中,我在构造函数中使用它们:
this._subChat = this.hub.messageChange.subscribe((message: ChatMessage) => {
this.message = message;
this.messageChange.next(this.message);
});
this._subGame = this.hub.gameChange.subscribe((game: GameState) => {
this.game.setGame(game);
});
Right now I am trying to use these 2 approaches to mock properties from mocked service:现在我正在尝试使用这两种方法来模拟来自模拟服务的属性:
Riht now my testing looks like this:现在我的测试看起来像这样:
describe('SignalRService', () => {
let signalrService: SignalRService;
const hubServiceMock = jasmine.createSpyObj('HubConnectionService', [
'isConnectionStarted',
]);
const messageChange = new Subject();
const gameChange = new Subject();
beforeEach(() => {
signalrService = new SignalRService(
hubServiceMock
);
let msg = {} as ChatMessage;
let gam = {} as GameState;
messageChange.next(msg);
gameChange.next(gam);
});
it('Service_ShouldBeCreated', () => {
spyOnProperty(hubServiceMock, 'messageChange', 'get').and.returnValue(
messageChange
);
spyOnProperty(hubServiceMock, 'gameChange', 'get').and.returnValue(
gameChange
);
expect(signalrService).toBeTruthy();
});
}
So in the test I create:所以在我创建的测试中:
service mock hubServiceMock
,服务模拟
hubServiceMock
,
fake messageChange = new Subject();
假
messageChange = new Subject();
, ,
fake gameChange = new Subject();
假
gameChange = new Subject();
, ,
i run for both .next
,我为两个
.next
竞选,
and I setup spy for properties:我为属性设置了间谍:
spyOnProperty(hubServiceMock, 'messageChange', 'get').and.returnValue( messageChange );
spyOnProperty(hubServiceMock, 'gameChange', 'get').and.returnValue( gameChange );
Why it does not work to me?为什么它对我不起作用? I receive an error:
我收到一个错误:
Cannot read property 'subscribe' of undefined
无法读取未定义的属性“订阅”
It doesn't work because hubServiceMock
doesn't have the fake subjects in its messageChange
and gameChange
, you need to set them before calling new SignalRService(hubServiceMock)
.它不起作用,因为
hubServiceMock
在其messageChange
和gameChange
中没有虚假主题,您需要在调用new SignalRService(hubServiceMock)
之前设置它们。
const hubServiceMock = jasmine.createSpyObj('HubConnectionService', [
'isConnectionStarted',
]);
const messageChange = new Subject();
const gameChange = new Subject();
// add this
hubServiceMock.messageChange = messageChange;
hubServiceMock.gameChange = gameChange;
then it should work, maybe small adjustments are needed.那么它应该可以工作,也许需要进行一些小的调整。
I would suggest to use a mocking lib for such cases to avoid pain.我建议在这种情况下使用 mocking lib 以避免疼痛。
For example with ng-mocks , the test might look like:例如使用ng-mocks ,测试可能如下所示:
describe('SignalRService', () => {
beforeEach(() => MockBuilder(SignalRService, ITS_MODULE));
const hubServiceMock = {
messageChange: new Subject(),
gameChange: new Subject(),
};
beforeEach(() => MockInstance(HubConnectionService, hubServiceMock));
it('Service_ShouldBeCreated', () => {
const signalrService = MockRender(SignalRService).point.componentInstance;
expect(signalrService).toBeTruthy();
hubServiceMock.messageChange.next({});
hubServiceMock.gameChange.next({});
// next assertions.
});
}
I ended up with approach, where I inject mocked service like this:我最终采用了方法,在其中注入了这样的模拟服务:
hubServiceMock = TestBed.inject(HubConnectionService);
Then I mock my Subject
s like this:然后我像这样模拟我的
Subject
:
it('Service_ShouldBeCreated', () => {
spyOn(hubServiceMock.messageChange, 'next');
spyOn(hubServiceMock.gameChange, 'next');
expect(signalrService).toBeTruthy();
});
And in other tests I can use methods of mocked service like that:在其他测试中,我可以使用这样的模拟服务方法:
let spyIsConnectionStarted = spyOn(hubServiceMock, 'isConnectionStarted');
spyIsConnectionStarted.and.returnValue(true);
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.