How to call a method using mouseenter in emberjs

I am trying to call a component method on mouseEnter but I am not able to get any out of that.

any one clarify the way how we have to call a method on mouseenter in emberjs?

here is my componet hbs:

<h1 mouseEnter=>Enter on me </h1>

my component:

import Ember from 'ember';

export default Ember.Component.extend({
  actions:{
    showCaution : function(){
        alert("hi");
    }
  }
});

But not working. here is the ember-twiddle