title: Updating property of object in array in NGRX/Redux store not working
body: <p>In my Reducer, I'm trying to update the property of an object in an array held within a dictionary collection, but it's not working and I can't figure out why. The results property of my state is a dictionary of key/value pairs, and the value is an array.</p>
  
  <p>I tried to use the map function to create a new array but my results and state does not update. This is my code:</p>
  
  <pre><code> case LOAD_SUCCESS: {
        const form = (action as LoadSuccessAction).form;
  
        return {
           results: {
             ...state.results,
             ...state.results['FORMS'].map(item =&gt; 
               item.id === form .id
                ? {...item, 'categories': form.categories}
                : item)           
           },    
          loading: false,
          loaded: true
        };
      } 
  </code></pre>
  
  <p>What am I doing wrong?</p>