TypeError：您在預期 stream 的地方提供了“未定義”。 您可以提供 Observable、Promise、Array 或 Iterable。 在<jasmine></jasmine>

Question

嗨，我已經在 ngonit 中添加了這段代碼，用於輪詢，添加后我所有的測試用例都失敗了。 請幫忙怎么解決？

  ngOnInit(): void {
this.timeInterval = interval(5000)
.pipe(
  startWith(0),
  switchMap(() => this.deviceService.getDeviceList())
)
.pipe(
  takeUntil(this.deviceService.flag$),
  repeatWhen(() => this.deviceService.flag$)
)
.subscribe((success: any) => {
  this.gridApi?.setRowData(this.updatedData);
  console.log("hello")
  this.updatedData = success;
}, retry(2));

這是完整的錯誤

HeadlessChrome 88.0.4324 (Windows 10.0.0) DeviceComponent testing columnresize of the grid for other scenario FAILED
    TypeError: You provided 'undefined' where a stream was expected. You can provide an Observable, Promise, Array, or Iterable.
        at <Jasmine>
        at subscribeTo (http://localhost:9876/_karma_webpack_/node_modules/rxjs/_esm2015/internal/util/subscribeTo.js:27:1)
        at innerSubscribe (http://localhost:9876/_karma_webpack_/node_modules/rxjs/_esm2015/internal/innerSubscribe.js:69:23)
        at TakeUntilOperator.call (http://localhost:9876/_karma_webpack_/node_modules/rxjs/_esm2015/internal/operators/takeUntil.js:11:52)
        at Observable.subscribe (http://localhost:9876/_karma_webpack_/node_modules/rxjs/_esm2015/internal/Observable.js:23:1)
        at RepeatWhenOperator.call (http://localhost:9876/_karma_webpack_/node_modules/rxjs/_esm2015/internal/operators/repeatWhen.js:11:1)
        at Observable.subscribe (http://localhost:9876/_karma_webpack_/node_modules/rxjs/_esm2015/internal/Observable.js:23:1)
        at DeviceComponent.ngOnInit (http://localhost:9876/_karma_webpack_/src/app/device/device.component.ts:99:4)
        at callHook (http://localhost:9876/_karma_webpack_/node_modules/@angular/core/__ivy_ngcc__/fesm2015/core.js:3937:1)
        at callHooks (http://localhost:9876/_karma_webpack_/node_modules/@angular/core/__ivy_ngcc__/fesm2015/core.js:3901:1)
        at executeInitAndCheckHooks (http://localhost:9876/_karma_webpack_/node_modules/@angular/core/__ivy_ngcc__/fesm2015/core.js:3842:1)
    Failed: Cannot read property 'unsubscribe' of undefined
        at <Jasmine>
        at DeviceComponent.ngOnDestroy (http://localhost:9876/_karma_webpack_/main.js:28373:23)
        at UserContext.<anonymous> (http://localhost:9876/_karma_webpack_/src/app/device/device.component.spec.ts:196:15)
        at ZoneDelegate.invoke (http://localhost:9876/_karma_webpack_/node_modules/zone.js/dist/zone-evergreen.js:365:1)
        at AsyncTestZoneSpec.onInvoke (http://localhost:9876/_karma_webpack_/node_modules/zone.js/dist/zone-testing.js:763:1)
        at ProxyZoneSpec.onInvoke (http://localhost:9876/_karma_webpack_/node_modules/zone.js/dist/zone-testing.js:302:1)
        at ZoneDelegate.invoke (http://localhost:9876/_karma_webpack_/node_modules/zone.js/dist/zone-evergreen.js:364:1)
        at Zone.runGuarded (http://localhost:9876/_karma_webpack_/node_modules/zone.js/dist/zone-evergreen.js:134:1)
        at runInTestZone (http://localhost:9876/_karma_webpack_/node_modules/zone.js/dist/zone-testing.js:885:1)
        at UserContext.<anonymous> (http://localhost:9876/_karma_webpack_/node_modules/zone.js/dist/zone-testing.js:823:1)
        at ZoneDelegate.invoke (http://localhost:9876/_karma_webpack_/node_modules/zone.js/dist/zone-evergreen.js:365:1)

HeadlessChrome 88.0.4324 (Windows 10.0.0): Executed 1 of 385 (1 FAILED) (0 secs / 1.732 secs) HeadlessChrome 88.0.4324 (Windows 10.0.0) DeviceComponent testing columnresize of the grid for other scenario FAILED TypeError: You provide '未定義'，其中預期為 stream。 您可以提供 Observable、Promise、Array 或 Iterable。 在 subscribeTo (http://localhost:9876/ karma_webpack /node_modules/rxjs/_esm2015/internal/util/subscribeTo.js:27:1) 在innerSubscribe (http://localhost:9876/ karma_webpack /node_modules/rxjs/_esm2015 /internal/innerSubscribe.js:69:23) 在 TakeUntilOperator.call (http://localhost:9876/ karma_webpack /node_modules/rxjs/_esm2015/internal/operators/takeUntil.js:11:52) 在 Observable.subscribe (http ://localhost:9876/karma_webpack/ node_modules /rxjs/_esm2015/internal/Observable.js:23:1) 在RepeatWhenOperator.call (http://localhost:9876/ karma_webpack /node_modules/rxjs/_esm2015/internal/operators/在DeviceComponent.ngOnInit (http://localhost: 9876/ karma_webpack /src/app/device/device.component.ts:99:4) 在 callHook (http://localhost:9876/ karma_webpack /node_modules/@angular/core/ ivy_ngcc /fesm2015/core.js:3937: 1) 在 callHooks (http://localhost:9876/ kar ma_webpack /node_modules/@angular/core/ ivy_ngcc /fesm2015/core.js:3901:1) 在 executeInitAndCheckHooks (http://localhost:9876/ karma_webpack /node_modules/@angular/core/ ivy_ngcc /fesm2015/core.js:3842 :1) 失敗：無法在 UserContext 的 DeviceComponent.ngOnDestroy (http://localhost:9876/ karma_webpack /main.js:28373:23) 處讀取未定義的屬性“取消訂閱”。 (http://localhost:9876/ karma_webpack /src/app/device/device.component.spec.ts:196:15) 在 ZoneDelegate.invoke (http://localhost:9876/ karma_webpack /node_modules/zone.js/ dist/zone-evergreen.js:365:1)

Answer 1

試試這個來調試它：

  ngOnInit(): void {
  console.log('this.deviceService.getDeviceList()', this.deviceService.getDeviceList());
  console.log('this.deviceService.flag$', this.device.getDeviceList());

  // make sure the above logs are not defined. 
 // If they are, you're not mocking them correctly when `ngOnInit` is called. 
 // `ngOnInit` is called after the first `fixture.detectChanges()` after 
 // the `TestBed.configureTestingModule({}).compileComponents();`.

this.timeInterval = interval(5000)
.pipe(
  startWith(0),
  switchMap(() => this.deviceService.getDeviceList())
)
.pipe(
  takeUntil(this.deviceService.flag$),
  repeatWhen(() => this.deviceService.flag$)
)
.subscribe((success: any) => {
  this.gridApi?.setRowData(this.updatedData);
  console.log("hello")
  this.updatedData = success;
}, retry(2));

Answer 2

1. 首先使用 xdescribe 禁用所有測試

2. 一個個啟用，直到發現有問題的 unittest 應該是使用提供者模擬方法並返回 observable 而不是 value 的提供者，例如

   {提供：TranslateService，useValue：{獲取：() => of('')，即時：() => of('')}}，{提供：SomeService，useValue：{getInfos：() => of( ), getList: () => [] },

• 即時應該返回值，不可觀察
• getInfos 應該返回一些可觀察的結果，而不是未定義的
• getList 應該以可觀察的形式返回數組，而不是具體的空數組...

對我來說，這些案例中的任何一個都確實導致了不一致的真陰性和假陽性......

3. 當您檢測到它時，修復提供程序並啟用測試的 rest。

祝你好運，這是一個卑鄙的人......

Answer 3

我有一個類似的問題。

我建議在您的 2 個 switchMap 運算符調用中檢查這些方法是否返回 Observables：

this.deviceService.getDeviceList()
this.deviceService.flag$

這就是我的原因。 switchMap 操作符必須返回一個 Observable。 因此，您的代碼中可能沒有訂閱 Observable 的情況發生。

如果您不需要在這些方法中返回 Observables，請嘗試使用 of()，如下所示：

// DO NOT forget to import 'of' from rxjs :)
  ngOnInit(): void {
this.timeInterval = interval(5000)
.pipe(
  startWith(0),
  switchMap(() => of(this.deviceService.getDeviceList()))
)
.pipe(
  takeUntil(this.deviceService.flag$),
  repeatWhen(() => of(this.deviceService.flag$))
)
.subscribe((success: any) => {
  this.gridApi?.setRowData(this.updatedData);
  console.log("hello")
  this.updatedData = success;
}, retry(2));