title: NGRX: TypeError: Actions must have a type property
body: <p>Being new to <code>ngrx</code> I am facing an exception and not sure why...</p>
  
  <p>I am trying to <code>dispatch</code> an <code>action</code> and handle it in an <code>effect</code>, but I keep getting the error: <code>TypeError: Actions must have a type property</code></p>
  
  <p>Actions:</p>
  
  <pre><code>export const TEST_ACTION = 'test_action';
  export class TryTest implements Action {
      readonly type = TEST_ACTION;
  
      constructor(public playload: any) {
      }
  }
  export type MyActions = TryTest;
  </code></pre>
  
  <p>Effects:</p>
  
  <pre><code>import * as MyActions from "./myactions.actions";
  
  @Injectable()
  export class MyEffects {
      @Effect()
      testEffect = this.actions$
          .ofType(MyActions.TEST_ACTION)
          .map((action: MyActions.TryTest) =&gt; {
              return 'something'
          });
  
      constructor(private actions$: Actions) {}
  }
  </code></pre>
  
  <p>Component:</p>
  
  <pre><code>this.store.dispatch(new MyActions.TryTest({ name: 'test' }));
  </code></pre>
  
  <p>I am using:</p>
  
  <p>effects: 4.0.5 and store: 4.0.3</p>