title: Why is immer complaining about computed properties?
body: <p>So based on a recent answer, I've started using ReduxStarterKit, which uses Immer in it's slice function.  Overall, I think the basic idea is brilliant.</p>
  
  <p>Unfortunately, when I try to actually make <em>use</em> of immer to make my life easier, I run into issues.  I've tried to simplify what I'm doing using my test reducer, and I'm still getting the same basic problem.  I've also turned off all my middleware (ElectronRedux) to make sure it's not a problem there.  The following is a simplified test reducer I'm using for testing:</p>
  
  <pre><code>const CounterSlice = createSlice({
    name: 'counter',
    reducers: {
      increment: (state)=&gt;{state.value = state.value + 1},
      decrement: (state)=&gt;{state.value = state.value - 1}
    },
    initialState: { value: 0 },
  })
  </code></pre>
  
  <p>The code above is pretty simple, and as far as I can tell <em>exactly</em> what Immer/ReduxStarterKit wants me to write.  Despite this, when I call the code I'm getting an error:  <code>Uncaught Error: Immer drafts cannot have computed properties</code></p>
  
  <p>What am I doing wrong?</p>
  
  <p>Edit:</p>
  
  <p>I just put together a simple demo app, just for the purposes of testing the basics.  The counter slice has coded here works perfectly.  I guess this is an interaction between Immer and another package -- just not sure where to go about debugging which <em>one</em>.  Is it a redux version issue, is it electron, electron redux, typescript, webpack, the list goes on and (painfully) on.</p>
  
  <p>I may have to recreate my basic app environment and test this one painful step at a time.  Ugh!</p>