feat: validate credentials for universe before request (#2367)

* feat: validate credentials for universe before request

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* nit: update comment

* remove validation before fetching next page

* nit: fix whitespace

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: ohmayr

googleapiclient/discovery.py

@@ -1050,6 +1050,9 @@ def createMethod(methodName, methodDesc, rootDesc, schema):
     def method(self, **kwargs):
         # Don't bother with doc string, it will be over-written by createMethod.
 
+        # Validate credentials for the configured universe.
+        self._validate_credentials()
+
         for name in kwargs:
             if name not in parameters.argmap:
                 raise TypeError("Got an unexpected keyword argument {}".format(name))

tests/test_discovery.py

@@ -2428,6 +2428,44 @@ def test_validate_credentials_with_already_validated_credentials(self):
 
             # TODO(google-api-python-client/issues/2365): Add test case for fake configured universe and fake credentials' universe.
 
+        def test_validate_credentials_before_api_request(self):
+            fake_universe = "foo.com"
+
+            http = google_auth_httplib2.AuthorizedHttp(
+                credentials=mock.Mock(universe_domain=universe.DEFAULT_UNIVERSE),
+                http=build_http(),
+            )
+            discovery = read_datafile("tasks.json")
+            tasks = build_from_document(
+                discovery,
+                http=http,
+                client_options=google.api_core.client_options.ClientOptions(
+                    universe_domain=universe.DEFAULT_UNIVERSE
+                ),
+            )
+
+            tasklists = tasks.tasklists()
+            request = tasklists.list()
+
+            # Check that credentials are indeed verified before request.
+            assert tasklists._validate_credentials()
+
+            http = google_auth_httplib2.AuthorizedHttp(
+                credentials=mock.Mock(universe_domain=fake_universe), http=build_http()
+            )
+            discovery = read_datafile("tasks.json")
+            tasks = build_from_document(
+                discovery,
+                http=http,
+                client_options=google.api_core.client_options.ClientOptions(
+                    universe_domain=universe.DEFAULT_UNIVERSE
+                ),
+            )
+
+            # Check that credentials are verified before request.
+            with self.assertRaises(universe.UniverseMismatchError):
+                request = tasks.tasklists().list()
+
 
 if __name__ == "__main__":
     unittest.main()