Vue + Pinia + Firebase Authentication: Fetch currentUser before Route Guard

Question

Recently I started to use Pinia as a global store for my Vue 3 Project. I use Firebase for the user authentication and am trying to load the current user before Vue is initialized. Ideally everything auth related should be in a single file with a Pinia Store. Unfortunately (unlike Vuex) the Pinia instance needs to be passed to the Vue instance before I can use any action and I believe that is the problem. On first load the user object in the store is empty for a short moment.

This is the store action that is binding the user (using the new Firebase Web v9 Beta) in auth.js

import { defineStore } from "pinia";
import { firebaseApp } from "@/services/firebase";
import {
  getAuth,
  onAuthStateChanged,
  getIdTokenResult,
} from "firebase/auth";

const auth = getAuth(firebaseApp);

export const useAuth = defineStore({
  id: "auth",
  state() {
    return {
      user: {},
      token: {},
    };
  },
  actions: {
    bindUser() {
      return new Promise((resolve, reject) => {
        onAuthStateChanged(
          auth,
          async (user) => {
            this.user = user;
            if (user) this.token = await getIdTokenResult(user);
            resolve();
          },
          reject()
        );
      });
    },
// ...
}})

and this is my main.js file

import { createApp } from "vue";
import App from "./App.vue";
import router from "./router";
import { createPinia } from "pinia";
import { useAuth } from "@/store/auth";

(async () => {
  const app = createApp(App).use(router).use(createPinia());
  const auth = useAuth();
  auth.bindUser();
  app.mount("#app");
})();

How can I set the user before anything else happens?

Answer 1

I figured it out. Had to register the router after the async stuff

//main.js
(async () => {
  const app = createApp(App);

  app.use(createPinia());
  const { bindUser } = useAuth();
  await bindUser();

  app.use(router);
  app.mount("#app");
})();