title: auth/argument-error facebook OAuth with firebase
body: <p>I have two options to signin with firebase SDK:
  1- signin() that uses email and password
  2- facebook() that uses <code>firebase.auth.FacebookAuthProvider();</code>
  Why My  <code>firebase.auth().getRedirectResult(provider)</code> is calling the <code>auth.$signInWithEmailAndPassword</code> which is in completly another funtion (login()) ?</p>
  
  <p>and I have the following error: <code>Pi {code: "auth/argument-error", message: "getRedirectResult failed: Expected 0 arguments but got 1."}</code></p>
  
  <p>Any Idea please ?</p>