Safari bug - click on select

HTML

<div id="app">
   <select @mousedown="runTest($event)" v-model="selectedValue">
       <option value>select to check your browser</option>
       <option value="1">first</option>
       <option value="2">second</option>
   </select>
</div>

CSS

body {
  padding: 2em;
}

Vue

new Vue({
  el: "#app",
  data: {
  		selectedValue: ''
  },
  methods: {
  	runTest(event) {
      if(event.target.value) {
        alert("It's too late to show an alert! I said on-clik stupid browser!");
      } else {
        alert("Alert on time! Good job dear browser!");
      }
      this.selectedValue = '';
    }
  }
})