How can a mock a http observable in Angular2 for when no api is written
<p>I'm new to both Angular2 and Rxjs and I am a little confused about a particular case.</p>

<p>I have a simple service:</p>

<pre><code>import { Injectable } from '@angular/core';
import { Observable, Subject } from 'rxjs/Rx';
import { Http, Response } from '@angular/http';

export interface Article {
  id: number;
  title: string;
  content: string;
  author: string;
}

@Injectable()
export class ArticleService {
  private _articles$: Subject&lt;Article[]&gt;;
  private baseUrl: string;
  private dataStore: {
    articles: Article[]
  };
  constructor(private http: Http) {
    this.baseUrl = 'http://localhost:3000'
    this.dataStore = { articles: [] };
    this._articles$ = &lt;Subject&lt;Article[]&gt;&gt;new Subject();
  }
  get articles$(){
    return this._articles$.asObservable();
  }

  loadAll(){
    //Observable.from(this.dummyData)
    this.http.get(`${this.baseUrl}/articles`)
    .map(response =&gt; response.json())
    .subscribe(data =&gt; {
      //debugger;
      this.dataStore.articles = data;
       // Push a new copy of our article list to all Subscribers.
      this._articles$.next(this.dataStore.articles)
    }, error =&gt; console.log('Could not load Articles'));
  }
}
</code></pre>

<p>And this works as expected , but what I would like to do is to be able to develope my service without a api endpoint and using an Observable that I can later swap out for the <code>http.request</code> . I tried to do this using Observable.from to convert a dummy data array to an observable but I get the errors </p>

<blockquote>
  <p><code>Type '{ id: number; title: string; content: string; author: string; }' is not assignable to type 'Article[]'</code></p>
</blockquote>

<p>I believe this is because it is returning each item separately instead of the array , can someone point me in the correct direction of how this should work</p>

<p><strong>Update</strong>:
for clarity the dummyData look like: </p>

<pre><code>private dummyData = [
      {
        id: 1,
        title: 'Title 1',
        content: 'content 1',
        author: 'author 1'
      },
      {
        id:2,
        title: 'Title 2',
        content: 'content 2',
        author: 'author 1'
      }
    ];
</code></pre>