将数组分配给具有 Mock 数据的另一个数组时出现角度未定义错误

Question

我正在尝试对使用数据解析器类获取“组”数据的组件进行单元测试。这是它的代码。

export class GroupsComponent implements OnInit, OnDestroy {
  group: IGroup;
  groups: IGroup[];

  constructor(
    private activatedRoute: ActivatedRoute,
    private titleService: Title,
    private userService: GroupsService
  ){
     this.titleService.setTitle('Home | Groups');
     this.groups = [];

     this.groupsComponentDataSubscription = this.activatedRoute
        .data
        .subscribe(
       data => {

        if(data['groupsResponse']){
           this.groupsResponse = data['groupsResponse'] as IGroupsResponse;
           this.groups = this.groupsResponse.groups;
       }
      })
    }
  }

为了测试，我使用模拟数据作为“groupsResponse”，如下所示：

let mockGroups: IGroup[] = [{
  groupName: "testGroup1",
  description : "group1 detail",
  apiRoles: ["foo", "bar", "monitoring"],
  kafkaClusters: [{
     clusterId: "cluster1",
     topics: ["foo", "bar"],
     connectClusters:[{
       clusteId: "testCluster1",
       connectorNames: ["foo", "bar"]
     }]
  }]
 },
groupName: "testGroup2",
  description : "group2 detail",
  apiRoles: ["foo", "bar", "foobar"],
  kafkaClusters: [{
     clusterId: "cluster2",
     topics: ["foo", "bar"],
     connectClusters:[{
       clusteId: "testCluster2",
       connectorNames: ["foo", "bar"]
     }]
  }]
 }
]

let mockGroupsResponse: IGroupsResponse = {
   groups: mockGroups
}

然后我将这个模拟值传递给 ActivatedRoute，如下所示：

let activatedRouteMock: any;

beforeEach(waitForAsync(() => {

activatedRouteMock = {
  data: of({groupsResponse: [mockGroupsResponse]})
};

TestBed.configureTestingModule({
 imports:[...],
 declarations: [GroupsComponent],
 providers:[..., {provide: ActivatedRoute, useValue: activatedRouteMock }]
}).compileComponents

我的解析器模拟数据已成功读取。但是，我面临的问题是尝试将响应中的组数组分配给局部变量。

constructor(
    private activatedRoute: ActivatedRoute,
    private titleService: Title,
    private userService: GroupsService
  ){
           ...
           ....
           this.groupsResponse = data['groupsResponse'] as IGroupsResponse; // groupsResponse is assigned as mock data -- console.log -> [{ groups: [object], [object]]
           this.groups = this.groupsResponse.groups; // here, not able to set this.groups array from groupsResponse. (undefined)
       }
      })
    }
  }

关于我在模拟中做错了什么的任何想法。在我使用 http 作为 Promise 从解析器获取数据的实际情况下，设置数组没有任何问题。但是，我的测试不起作用

Answer 1

从构造函数中移除 API 调用并将它们移动到 ngOnInit 中。

构造函数应该只用于注入依赖。 Ref 构造函数在你的模拟服务准备好之前被触发。