get preact files into root

src/auth.js

@@ -0,0 +1,43 @@
+import {
+	trackEvent
+} from './analytics';
+
+import firebase from 'firebase/app'
+
+export const auth = {
+	logout() {
+		firebase.auth().signOut();
+	},
+	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 () {
+				trackEvent('fn', 'loggedIn', providerName);
+				// Save to recommend next time
+				window.db.local.set({
+					lastAuthProvider: providerName
+				});
+			})
+			.catch(function (error) {
+				utils.log(error);
+				if (error.code === 'auth/account-exists-with-different-credential') {
+					alert(
+						'You have already signed up with the same email using different social login'
+					);
+				}
+			});
+	}
+}