Counter.vue

<template>
  <div class="counter">
    <div class="col-md-6 col-md-offset-3 well">

      <h1>Contador con Vuejs 2, Vuex y Socket.IO</h1>

      <div class="clearfix"><hr /></div>

      <button class="btn btn-block btn-info" @click="increment">
        Incrementar
      </button>
      <h4 class="text-center">{{ count }}</h4>
      <button class="btn btn-block btn-info" @click="decrement">
        Decrementar
      </button>

    </div>
  </div>
</template>

<script>
  export default {
    methods: {
      increment () {
        this.$store.dispatch('socket_increment')
      },
      decrement () {
        this.$store.dispatch('socket_decrement')
      }
    },
    computed: {
      count () {
        return this.$store.state.counterModule.count
      }
    }
  }
</script>