0👍
Try it like this:
import Vue from 'nativescript-vue'
import App from './components/App'
import * as firebase from 'nativescript-plugin-firebase'
/* how to access App component's instance here */
firebase.init().then(() => {
console.log('firebase initialized')
/* how to call log() or change msg's value here */
myApp.log()
})
const myApp = new Vue({
render: h => h('frame', [h(App)])
}).$start()
But it is untested.
Source:stackexchange.com