title: Updating nested data in redux store
body: <p>What's the best/correct way to update a nested array of data in a store using redux?</p>
  
  <p>My store looks like this:</p>
  
  <pre><code>{
      items:{
          1: {
              id: 1,
              key: "value",
              links: [
                  {
                      id: 10001
                      data: "some more stuff"
                  },
                  ...
              ]
          },
          ...
      }
  }
  </code></pre>
  
  <p>I have a pair of asynchronous actions that updates the complete <code>items</code> object but I have another pair of actions that I want to update a specific <code>links</code> array. </p>
  
  <p>My reducer currently looks like this but I'm not sure if this is the correct approach:</p>
  
  <pre><code>  switch (action.type) {
      case RESOURCE_TYPE_LINK_ADD_SUCCESS:
        // TODO: check whether the following is acceptable or should we create a new one?
        state.items[action.resourceTypeId].isSourceOf.push(action.resourceTypeLink);
        return Object.assign({}, state, {
          items: state.items,
        });
    }
  </code></pre>