Add type hints for tests/unittest.py. (#12347)

In particular, add type hints for get_success and friends, which are then helpful in a bunch of places.

tests/handlers/test_e2e_keys.py

@@ -463,8 +463,10 @@ class E2eKeysHandlerTestCase(unittest.HomeserverTestCase):
         res = e.value.code
         self.assertEqual(res, 400)
 
-        res = self.get_success(self.handler.query_local_devices({local_user: None}))
-        self.assertDictEqual(res, {local_user: {}})
+        query_res = self.get_success(
+            self.handler.query_local_devices({local_user: None})
+        )
+        self.assertDictEqual(query_res, {local_user: {}})
 
     def test_upload_signatures(self) -> None:
         """should check signatures that are uploaded"""

tests/handlers/test_federation.py

@@ -375,7 +375,8 @@ class FederationTestCase(unittest.FederatingHomeserverTestCase):
         member_event.signatures = member_event_dict["signatures"]
 
         # Add the new member_event to the StateMap
-        prev_state_map[
+        updated_state_map = dict(prev_state_map)
+        updated_state_map[
             (member_event.type, member_event.state_key)
         ] = member_event.event_id
         auth_events.append(member_event)
@@ -399,7 +400,7 @@ class FederationTestCase(unittest.FederatingHomeserverTestCase):
                 prev_event_ids=message_event_dict["prev_events"],
                 auth_event_ids=self._event_auth_handler.compute_auth_events(
                     builder,
-                    prev_state_map,
+                    updated_state_map,
                     for_verification=False,
                 ),
                 depth=message_event_dict["depth"],

tests/handlers/test_oidc.py

@@ -354,10 +354,11 @@ class OidcHandlerTestCase(HomeserverTestCase):
         req = Mock(spec=["cookies"])
         req.cookies = []
 
-        url = self.get_success(
-            self.provider.handle_redirect_request(req, b"http://client/redirect")
+        url = urlparse(
+            self.get_success(
+                self.provider.handle_redirect_request(req, b"http://client/redirect")
+            )
         )
-        url = urlparse(url)
         auth_endpoint = urlparse(AUTHORIZATION_ENDPOINT)
 
         self.assertEqual(url.scheme, auth_endpoint.scheme)

tests/handlers/test_user_directory.py

@@ -351,6 +351,7 @@ class UserDirectoryTestCase(unittest.HomeserverTestCase):
             self.handler.handle_local_profile_change(regular_user_id, profile_info)
         )
         profile = self.get_success(self.store.get_user_in_directory(regular_user_id))
+        assert profile is not None
         self.assertTrue(profile["display_name"] == display_name)
 
     def test_handle_local_profile_change_with_deactivated_user(self) -> None:
@@ -369,6 +370,7 @@ class UserDirectoryTestCase(unittest.HomeserverTestCase):
 
         # profile is in directory
         profile = self.get_success(self.store.get_user_in_directory(r_user_id))
+        assert profile is not None
         self.assertTrue(profile["display_name"] == display_name)
 
         # deactivate user