how to fix Error: ASSERTION ERROR: Should be run in update mode [Expected=> false == true <=Actual]

Question

我正在用 angular 和 ChangeDetectorRef

编写代码

函数本身运行良好。

getVersionInfos() {
concat(
  of(
    this.getApiSubs = this.aboutInfoService.getApiVersion().subscribe((data) => {
      if (data) {
        this.apiData = data;
        this.applicationCopyright = data.find(dt => dt.Name === "Web API Details").Value;          }
    })
  ),
  of(
    this.getEngineSubs = this.aboutInfoService.getEngineVersion().subscribe((data) => {
      if (data) {
        this.engineData = data;
        this.engineDetails = data.find(dt => dt.itemcode === "VER").versiontext;
        this.cd.detectChanges();
      }
    })
  )
);

}

当我为其编写单元测试代码时，它总是在

上失败

        this.cd.detectChanges();

这给了我这个错误

错误：断言错误：应该是运行更新模式 [预期=> false == true <=实际]

这是规范代码块

beforeEach(async(() => {
TestBed.configureTestingModule({
  declarations: [
    AboutComponent
  ],
  imports: [
    MatBottomSheetModule,
    HttpClientTestingModule
  ],
  providers: [
    {
      provide: AboutInfoService,
      useValue: jasmine.createSpyObj("AboutInfoService", [
        "getApiVersion",
        "getEngineVersion"
      ]),
    },
    {
      provide: ChangeDetectorRef,
      useValue: jasmine.createSpyObj("ChangeDetectorRef", ["detectChanges"])
    }
  ]
})
.compileComponents();

aboutInfoService = TestBed.get(AboutInfoService);
aboutInfoService.getApiVersion.and.returnValue(of(mockApiResponse));
aboutInfoService.getEngineVersion.and.returnValue(of(mockEngineResponse));



}));

  beforeEach(() => {
    fixture = TestBed.createComponent(AboutComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it("should create", () => {
    expect(component).toBeTruthy();
  });

如果我删除代码

        this.cd.detectChanges();

从函数中可以通过单元测试

Answer 1

我已经搞定了，

我已将函数 getVersionInfos 放在 ngOnInit 中而不是构造函数中

Answer 2

我在 Angular 11 中也有这个错误。问题是我正在执行：

this.cdr.detectChanges();

在构造函数内部，这是错误的。我把它移到了 ngOnInit()

Answer 3

避免在构造函数中或将从构造函数调用的方法中保留 this._changeDetectorRef.detectChanges() 方法调用。 Angular 在这两种情况下都会抛出此错误。

how to fix Error: ASSERTION ERROR: Should be run in update mode [Expected=> false == true <=Actual]

how to fix Error: ASSERTION ERROR: Should be run in update mode [Expected=> false == true <=Actual]

jasmine

typescript

karma-jasmine

angular