If I have a page that can only be accessed by authenticated users, how do I check if a user is authenticated or not?

I tried using (firebase.auth().currentUser !== null) but I am getting an error saying: TypeError: firebase.auth is not a function

I have the following configuration:

const express = require('express'),
      firebase = require('firebase'),
      app = express();

app.use(express.static("/public"));

var config = {
   apiKey: "xxxx",
   authDomain: "xxxx",
   databaseURL: "xxxx",
   projectId: "xxxx",
   storageBucket: "xxxx",
   messagingSenderId: "xxxx"
};

firebase.initializeApp(config); 

app.get("/dashboard", (request, response) => {
   if (firebase.auth().currentUser !== null){
       response.render("dashboard.ejs")
   }
   else{
       response.render("login.ejs");
   }
});

If I have a page that can only be accessed by authenticated users, how do I check if a user is authenticated or not?

I tried using (firebase.auth().currentUser !== null) but I am getting an error saying: TypeError: firebase.auth is not a function

I have the following configuration:

const express = require('express'),
      firebase = require('firebase'),
      app = express();

app.use(express.static("/public"));

var config = {
   apiKey: "xxxx",
   authDomain: "xxxx",
   databaseURL: "xxxx",
   projectId: "xxxx",
   storageBucket: "xxxx",
   messagingSenderId: "xxxx"
};

firebase.initializeApp(config); 

app.get("/dashboard", (request, response) => {
   if (firebase.auth().currentUser !== null){
       response.render("dashboard.ejs")
   }
   else{
       response.render("login.ejs");
   }
});

• javascript
• node.js
• firebase
• express
• firebase-authentication

• Possible duplicate of firebase.auth is not a function – Grimthorr Commented Jun 1, 2018 at 13:08
• I've seen this before, tried the solutions there and had no luck. What might be the case of my question is, is it better to call firebase.auth().currentUser or is there a better way to access this through the admin SDK? – rgoncalv Commented Jun 1, 2018 at 13:11

1 Answer 1

Your code is in an Express app, which means it runs on the server. The Firebase SDK you're using is meant for use on client devices, and won't work well in your Express environment. There is no concept of a "current user" on the server. Of course a user ID can be passed to the server with each request, but the server itself is stateless.

In your Express server you'll want to use the Firebase Admin SDK. Have a look at this Cloud Functions sample on how to build an authenticated endpoint.