firebase working but firebase.auth() not working in Vue.js

Question

I ran

npm i firebase

and have

import firebase from 'firebase/compat/app'

but when i run

console.log(firebase.auth())

I get an error message of

app.js:280 Uncaught FirebaseError: Firebase: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp() (app-compat/no-app).
    at app (firebaseNamespaceCore.ts?1484:102:1)
    at Object.serviceNamespace [as auth] (firebaseNamespaceCore.ts?1484:152:1)
    at eval (HelloWorld.vue?e90b:24:1)
    at Module../node_modules/babel-loader/lib/index.js??clonedRuleSet-40.use[0]!./node_modules/vue-loader/dist/index.js??ruleSet[0].use[0]!./src/components/HelloWorld.vue?vue&type=script&lang=js (app.js:30:1)
    at __webpack_require__ (app.js:277:33)
    at fn (app.js:517:21)
    at eval (HelloWorld.vue?vue&type=script&lang=js:5:213)
    at Module../src/components/HelloWorld.vue?vue&type=script&lang=js (app.js:140:1)
    at __webpack_require__ (app.js:277:33)
    at fn (app.js:517:21)

However, when I just run console.log(firebase) I get correct data output in console. I have also setup firebase correctly as documented here but firebause.auth() is still not working. I am working in Vue3 but I don't think that part matters, still trying to find a solution.

I am currently trying to get firebaseUI to work and this is the step I am getting stuck in. Once I'm able to get firebause.auth() to work, I'll be able to initialize the firebaseUI widget by running:

var ui = new firebaseui.auth.AuthUI(firebase.auth());

my ./src/firebaseConfig.js code:

import { initializeApp } from "firebase/app";

const firebaseConfig = {
  apiKey: "code",
  authDomain: "code",
  projectId: "code",
  storageBucket: "code",
  messagingSenderId: "code",
  appId: "code",
  measurementId: "code"
};

const firebaseApp = initializeApp(firebaseConfig);
export default firebaseApp

My component file using firebaseConfig.js in ./src/components/HellowWorld.vue :

<template>
  <div class="hello">
    <h1>{{ msg }}</h1>
    <div id="sign-in-status"></div>
    <div id="sign-in"></div>
    <pre id="account-details"></pre>
  </div>
</template>

<script>
import firebaseConfig from '../firebaseConfig';

import firebase from 'firebase/compat/app';
import * as firebaseui from 'firebaseui'
import 'firebaseui/dist/firebaseui.css'

console.log(firebaseConfig);
console.log(firebase);

// Initialize the FirebaseUI Widget using Firebase.
var ui = new firebaseui.auth.AuthUI(firebase.auth());
ui




export default {
  name: 'HelloWorld',
  props: {
    msg: String
  },
}
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
</style>

both

console.log(firebaseConfig);
console.log(firebase);

works but

// Initialize the FirebaseUI Widget using Firebase.
var ui = new firebaseui.auth.AuthUI(firebase.auth());
ui

produces an error as copy and pasted above.

Answer 1

I had same problem, then I found points. And I understood why somebody was OK, others was bug.

1. Initialization needs to App based, of course before call firebaseUI. We have some ways to do that main.js, import configuration.js, before auth timing...etc.

2. Initialized firebaseApp (your firebaseConfig.js) is different from import firebase from 'firebase/compat/app'

3. If new firebaseUI is called before Initialization or no initialized, we get error. Then take care Lifecycle of Vue.

Probably you need, Import firebaseApp, Not firebaseConfig to HellowWorld.vue for getting Initialized.

In my case, my 'new firebaseUI' is in mounted() of ChildView. I initialize firebaseApp at main.ts, so childView doesn't need initialization any more, only import firebase from 'firebase/compat/app'.

If you need code, I can show you my case.