title: Why must must ngrx / redux effects return actions? Is using a noop action like elm considered bad practice?
body: <p>I'm using a redux-style state management design with Angular and ngrx/store and ngrx/effects. Whenever I don't return an action from an effect, I get an error: </p>
  
  <pre><code>Cannot read property 'type' of undefined
  </code></pre>
  
  <p>I researched the issue and found that in an elm architecture there is something called a "noop" action that does nothing that you can call when you don't want to chain another action with your effect. Calling this noop action everywhere seems extremely repetitive to me. I am wondering if this would be a bad practice to follow. Is there a reason you cannot have an effect that does not return an action? Is the intention of effects to always have 1 action fire another action? I'm wondering if I am misunderstanding how to use effects.</p>
  
  <p>Thanks!</p>