handle token expire

google.py

@@ -1,18 +1,23 @@
 import os
 from flask import Flask, redirect, url_for
 from flask_dance.contrib.google import make_google_blueprint, google
+from oauthlib.oauth2.rfc6749.errors import InvalidGrantError, TokenExpiredError
 
 app = Flask(__name__)
 app.secret_key = os.environ.get("FLASK_SECRET_KEY", "supersekrit")
 app.config["GOOGLE_OAUTH_CLIENT_ID"] = os.environ.get("GOOGLE_OAUTH_CLIENT_ID")
 app.config["GOOGLE_OAUTH_CLIENT_SECRET"] = os.environ.get("GOOGLE_OAUTH_CLIENT_SECRET")
-google_bp = make_google_blueprint(scope=["profile", "email"])
+google_bp = make_google_blueprint(scope=["openid", "https://www.googleapis.com/auth/userinfo.email", "https://www.googleapis.com/auth/userinfo.profile"])
 app.register_blueprint(google_bp, url_prefix="/login")
 
-@app.route("/")
+@app.route('/')
 def index():
     if not google.authorized:
         return redirect(url_for("google.login"))
-    resp = google.get("/oauth2/v1/userinfo")
-    assert resp.ok, resp.text
-    return "You are {email} on Google".format(email=resp.json()["email"])
+    try:
+        resp = google.get("/oauth2/v1/userinfo")
+        assert resp.ok, resp.text
+    except (InvalidGrantError, TokenExpiredError):
+        return redirect(url_for("google.login"))
+
+    return "You are {email} on Google".format(email=resp.json()["email"])