forkJoin is deprecated: resultSelector is deprecated, pipe to map instead

Question

I'm working on an Angular 6 project.

Running ng lint gives the following Warning:

"forkJoin is deprecated: resultSelector is deprecated, pipe to map instead"

 forkJoin(...observables).subscribe( 

Any idea? Can't seem to find any information about this deprecation.

I just generated a brand new Angular application "ng new forkApp" with Angular CLI: 6.1.5

source:

import { Component, OnInit } from '@angular/core'; import { HttpClient } from '@angular/common/http'; import { forkJoin } from 'rxjs';  @Component({   selector: 'app-root',   templateUrl: './app.component.html',   styleUrls: ['./app.component.css'] }) export class AppComponent implements OnInit {   title = 'forkApp';    constructor(private http: HttpClient) {}    ngOnInit() {     console.log('ngOnInit...');      const obs = [];     for (let i = 1; i < 4; i++) {        const ob = this.http.get('https://swapi.co/api/people/' + i);       obs.push(ob);      }      forkJoin(...obs)       .subscribe(         datas => {           console.log('received data', datas);         }       );    } } 

"dependencies" section from package.json file:

  "dependencies": {     "@angular/animations": "^6.1.0",     "@angular/common": "^6.1.0",     "@angular/compiler": "^6.1.0",     "@angular/core": "^6.1.0",     "@angular/forms": "^6.1.0",     "@angular/http": "^6.1.0",     "@angular/platform-browser": "^6.1.0",     "@angular/platform-browser-dynamic": "^6.1.0",     "@angular/router": "^6.1.0",     "core-js": "^2.5.4",     "rxjs": "^6.0.0",     "zone.js": "~0.8.26"   }, 

Once all three GET requests are done I got all data in "datas" array. The issue is that once I run: ng lint I got this:

C:\forkApp>ng lint

WARNING: C:/forkApp/src/app/app.component.ts[26, 5]: forkJoin is deprecated: resultSelector is deprecated, pipe to map instead

Answer 1

I was able to fix this by getting rid of the ellipsis:

forkJoin(observables).subscribe();

As long as observables is already an array, it should have the same result.

Answer 2

forkJoin(observable1, observable2)   // WORKING - deprecation warning (memberObservables) => forkJoin(memberObservables)) // warning, too forkJoin([observable1, observable2]) // WORKING - no warning (memberObservables: Array<any>) => forkJoin(memberObservables)) // no warning