chore(dev): add another nested mutation

Author: Guillaume Chau

shells/dev/target/Counter.vue

@@ -16,6 +16,7 @@
       <p>foo: {{ foo }}</p>
       <p>twoFoos: {{ twoFoos }}</p>
       <button @click="addBar">Add bar</button>
+      <button @click="removeBar">Remove bar</button>
     </div>
   </div>
 </template>
@@ -69,7 +70,8 @@ export default {
     },
 
     ...mapMutations('nested', {
-      addBar: 'ADD_BAR'
+      addBar: 'ADD_BAR',
+      removeBar: 'REMOVE_BAR'
     })
   }
 }

shells/dev/target/store.js

@@ -62,6 +62,9 @@ export default new Vuex.Store({
       mutations: {
         ADD_BAR: (state) => {
           state.foo += 'bar'
+        },
+        REMOVE_BAR: (state) => {
+          state.foo = state.foo.substr('bar'.length)
         }
       }
     }