JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://unpkg.com/vue"></script>

<div id="app">
  <h2 v-for="item in toArray(map)">{{ item }}</h2>
  <button @click="append">
    Add an item
  </button>
</div>

JavaScript

new Vue({
  el: '#app',
  data: { map: new Map(), counter: 0 },
  methods: {
    append() {
      this.map.set(++this.counter, `some value ${this.counter}`)
      // vue's reactivity doesn't know anything changed
      // so we tell it manually to update
      this.$forceUpdate()
    },
    toArray(dataSet) {
      return Array.from(dataSet)
    }
  }
})