A Vue Alert Demo

alert.js

const alert = () => {
  const VmConstructor = Vue.extend({
    template: `
<div>
      <button @click="$emit('yes')">yes</button>
      <button @click="$emit('no')">no</button>
</div>
     `
  })
  const instance = getAnInstance(VmConstructor)

  mount(instance)

  return new Promise((resolve, reject) => {
    instance.$on('yes', (content = true) => {
      resolve(content)
      destroy(instance)
    })
    instance.$on('no', (message = 'cancel') => {
      reject(createMessage(message))
      destroy(instance)
    })
  })
}

function createMessage (content) {
  return `[vv] ${conente}`
}

function mount(vm) {
    document.body.appendChild(vm.$el)
}

function destroy(vm) {
    document.body.removeChild(vm.$el)
    vm.$destroy()
}


function getAnInstance(VmConstructor, propsData = {}) {
    return new VmConstructor({
        el: document.createElement('div'),
        propsData
    })
}

async function run () {
  console.log(await alert())
}
run()