title: Dynamically creating a reactive array in the Vuex's state
body: <p>My component would like to add a new reactive-array field to the SST (vuex). I tried in beforeCreate hook, but the added array is not reactive; it's just a plain JS array.</p>
  <p>Note that this is not the same as adding/removing elements from an existing array created at the Vue's initialization time. Such arrays are &quot;wrapped&quot; and become reactive as expected, mindful of &quot;<a href="https://v2.vuejs.org/v2/guide/list.html#Array-Change-Detection" rel="nofollow noreferrer">Array Change Detection</a>&quot; gotchas.</p>
  <p>In my case, I'm trying to dynamically add an entirely new field of array type to the SST and make it reactive at the same time. Possible?</p>