adds unit test, alters error handling code

Author: chalmerlowe

google_auth_oauthlib/flow.py

@@ -458,13 +458,21 @@ def run_local_server(
             local_server.timeout = timeout_seconds
             local_server.handle_request()
 
-            if wsgi_app.last_request_uri is None:
-                # Timeout occurred
-                raise WSGITimeout("Timed out waiting for response from authorization server")
+            # if wsgi_app.last_request_uri is None:
+            #     # Timeout occurred
+            #     raise WSGITimeout("Timed out waiting for response from authorization server")
 
             # Note: using https here because oauthlib is very picky that
             # OAuth 2.0 should only occur over https.
-            authorization_response = wsgi_app.last_request_uri.replace("http", "https")
+            try:
+                authorization_response = wsgi_app.last_request_uri.replace(
+                    "http", "https"
+                )
+            except AttributeError as e:
+                raise WSGITimeout(
+                    "Timed out waiting for response from authorization server"
+                ) from e
+
             self.fetch_token(
                 authorization_response=authorization_response, audience=token_audience
             )
@@ -517,5 +525,5 @@ def __call__(self, environ, start_response):
         return [self._success_message.encode("utf-8")]
 
 
-class WSGITimeout(Exception):
+class WSGITimeout(AttributeError):
     """Raised when the WSGI server times out waiting for a response."""

tests/unit/test_flow.py

@@ -496,3 +496,20 @@ def test_run_local_server_logs_and_prints_url(
             urllib.parse.quote(instance.redirect_uri, safe="")
             in print_mock.call_args[0][0]
         )
+
+    @mock.patch("google_auth_oauthlib.flow.webbrowser", autospec=True)
+    @mock.patch("wsgiref.simple_server.make_server", autospec=True)
+    def test_run_local_server_timeout(
+        self, make_server_mock, webbrowser_mock, instance, mock_fetch_token
+    ):
+        mock_server = mock.Mock()
+        make_server_mock.return_value = mock_server
+
+        # handle_request does nothing (simulating timeout), so last_request_uri remains None
+        mock_server.handle_request.return_value = None
+
+        with pytest.raises(flow.WSGITimeout):
+            instance.run_local_server(timeout_seconds=1)
+
+        webbrowser_mock.get.assert_called_with(None)
+        webbrowser_mock.get.return_value.open.assert_called_once()