Update data using vuex

You can wrap your parameters in 1 payload object:

In your component

this.$store.dispatch('updateCategory', {
  id: this.$route.params.id,
  data: this.category
});

in your store, you need to made new object when edit categories array (you can read more about immutable)

const state = {
   categories: []
};

//mutations:
[mutationType.UPDATE_CATEGORY] (state, payload) {
    state.categories = state.categories.map(category => {
      if (category.id === payload.id) {
        return Object.assign({}, category, payload.data)
      }
      return category
    })
}

//actions:
updateCategory({commit}, payload) {
  categoriesApi.updateCategory(payload.id, payload.data).then((response) => {
    commit(mutationType.UPDATE_CATEGORY, payload);
    router.push({name: 'categories'});
  })
}

and much more simple, just use methods to modify arrays (never modify them directly) (check this: https://vuejs.org/2016/02/06/common-gotchas/#Why-isn%E2%80%99t-the-DOM-updating even old and DOM related, is still valid)

So just find your object and replace with splice in your mutation:

const index = state.objectsArray.map(o => o.id).indexOf(newObject.id);
state.objectsArray.splice(index, 1, newObject);