Can't get currentUser on load

Question

When trying to check if a user is signed in via firebase.auth().currentUser like this:

if (firebase.auth().currentUser === null) {
  console.log('User not signed in');
}

Whenever I refresh the page, or navigate around the above returns null (even though I have just logged in).

The weird thing is, that if I log

console.log(firebase.auth().currentUser) // This returns null
console.log(firebase.auth()) // Here I can inspect the object and currentUser exists...!

I don't really know what's going on here. I'm using React and Redux, but it shouldn't really matter I'd say.

Is there a small delay where the firebase initialises and you can't access the currentUser? If so, how can I see it in the log output of firebase.auth()?

Answer 1

This is a commonly asked question. https://firebase.google.com/docs/auth/web/manage-users You need to add an observer to onAuthStateChanged to detect the initial state and all subsequent state changes,

firebase.auth().onAuthStateChanged(function(user) {
  if (user) {
    // User is signed in.
  } else {
    // No user is signed in.
  }
});