[英]How to test the ngrx store.select of an Observable, in angular5?
[英]Getting the error Type 'Observable<{}>' is not assignable to type 'Observable<User>'. when trying to use @ngrx/store's store.select()
我試圖在 API 調用后設置我的$currentUser
,但我不斷收到錯誤消息:
[default]
Type 'Observable<{}>' is not assignable to type 'Observable<User>'.
Type '{}' is not assignable to type 'User'.
Property 'username' is missing in type '{}'.
我拋出錯誤的組件如下所示:
import {Component, state} from '@angular/core';
import { Observable } from "rxjs";
import { User } from '../../../../models/user';
import { Store } from '@ngrx/store';
import { AppState } from '../../../../reducers';
import {UserService} from "../../../../services/user.service";
@Component({
selector: 'user-center',
templateUrl: 'user-center.component.html',
styleUrls: ['user-center.component.scss']
})
export class UserCenter {
$currentUser: Observable<User>;
userService: UserService;
constructor(
userService: UserService,
public store: Store<AppState>
) {
this.userService = userService;
this.$currentUser = this.store.select('user');
}
ngOnInit() {
this.userService.initialise();
}
}
我的效果是這樣的::
import { Injectable } from '@angular/core';
import { Effect, StateUpdates, toPayload } from '@ngrx/effects';
import { Observable } from 'rxjs/Observable';
import { AppState } from '../reducers';
import { UserService } from '../services/user.service';
import { UserActions } from "../actions/UserActions";
@Injectable()
export class UserEffects {
constructor(
private updates$: StateUpdates<AppState>,
private userService: UserService,
private userActions: UserActions,
) {}
@Effect() CurrentUser$ = this.updates$
.whenAction('INIT_USER')
.switchMap(() => this.userService.getUser()
.map(user => this.userActions.setCurrentUser(user))
.catch(() => Observable.of({ type: 'GET_USER_FAILED' })
));
}
您應該更改構造函數並將依賴項設置為 Store as public store: Store<User>
。 或者你真的需要它作為Store<AppState>
? 應該使用泛型src/operator/select.ts
自動設置類型:
constructor(
userService: UserService,
public store: Store<User>
) {
this.userService = userService;
this.$currentUser = this.store.select('user');
}
或者,拋出錯誤是因為您將$currentUser
定義為:
$currentUser: Observable<User>;
因此您可以在將數據分配給this.$currentUser
時在 TypeScript 中使用類型斷言:
this.$currentUser = <Observable<User>>this.store.select('user');
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