window.logout = function logout() { firebase.auth().signOut(); }; function login(providerName) { var provider; if (providerName === 'facebook') { provider = new firebase.auth.FacebookAuthProvider(); } else if (providerName === 'twitter') { provider = new firebase.auth.TwitterAuthProvider(); } else if (providerName === 'google') { provider = new firebase.auth.GoogleAuthProvider(); provider.addScope('https://www.googleapis.com/auth/userinfo.profile'); } else { provider = new firebase.auth.GithubAuthProvider(); } return firebase .auth() .signInWithPopup(provider) .then(function() {}) .catch(function(error) { alert( 'You have already signed up with the same email using different social login' ); utils.log(error); }); } window.login = login;