store-def.js

const store = new Vuex.Store({
  state: {
    count: 0
  },
  mutations: {
    update (state, value) {
      state.count = value
    }
  },
  actions: {
    update ({ commit }, value) {
      axios
        .get('/count', value)
        .then(({ data }) => {
          commit('update', data.value)
        })
    },
    reset ({ commit }) {
      commit('update', 0)
    }
  }
})