fix(datatracker): attempt to auto-refresh token

#117

datatracker/oauth.py

@@ -140,22 +140,37 @@ def get_client(request):
 
     As a side effect, if session is not authenticated,
     clears OAuth data from session.
+
+    Will attempt to auto-refresh the token if expired.
     """
 
+    def token_updater(token: str):
+        request.session[OAUTH_TOKEN_KEY] = token
+
     if is_datatracker_oauth_enabled() and OAUTH_TOKEN_KEY in request.session:
+        provider = get_provider()
         session = OAuth2Session(
             CLIENT_ID,
             scope=OAUTH_SCOPES,
             redirect_uri=_get_redirect_uri(),
-            token=request.session[OAUTH_TOKEN_KEY])
-        provider = get_provider()
+            token=request.session[OAUTH_TOKEN_KEY],
+
+            auto_refresh_url=provider.token_endpoint,
+            auto_refresh_kwargs=dict(
+                client_id=CLIENT_ID,
+                client_secret=CLIENT_SECRET,
+                scope=OAUTH_SCOPES,
+            ),
+            token_updater=token_updater,
+        )
         try:
-            session.get(provider.userinfo_endpoint).json()
+            user_info = session.get(provider.userinfo_endpoint).json()
         except Exception:
-            # Most likely, token expired.
+            log.exception("Unable to retrieve user info")
             clear_session(request)
             return None
         else:
+            request.session[OAUTH_USER_INFO_KEY] = user_info
             return session
     else:
         return None