Remove unused `# type: ignore`s (#12531)

Over time we've begun to use newer versions of mypy, typeshed, stub
packages---and of course we've improved our own annotations. This makes
some type ignore comments no longer necessary. I have removed them.

There was one exception: a module that imports `select.epoll`. The
ignore is redundant on Linux, but I've kept it ignored for those of us
who work on the source tree using not-Linux. (#11771)

I'm more interested in the config line which enforces this. I want
unused ignores to be reported, because I think it's useful feedback when
annotating to know when you've fixed a problem you had to previously
ignore.

* Installing extras before typechecking

Lacking an easy way to install all extras generically, let's bite the bullet and
make install the hand-maintained `all` extra before typechecking.

Now that https://github.com/matrix-org/backend-meta/pull/6 is merged to
the release/v1 branch.

5 files changed, 23 insertions, 21 deletions

diff --git a/tests/handlers/test_register.py b/tests/handlers/test_register.py
index 45fd30cf43..b6ba19c739 100644
--- a/tests/handlers/test_register.py
+++ b/tests/handlers/test_register.py
@@ -193,8 +193,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
 
     @override_config({"limit_usage_by_mau": True})
     def test_get_or_create_user_mau_not_blocked(self):
-        # Type ignore: mypy doesn't like us assigning to methods.
-        self.store.count_monthly_users = Mock(  # type: ignore[assignment]
+        self.store.count_monthly_users = Mock(
             return_value=make_awaitable(self.hs.config.server.max_mau_value - 1)
         )
         # Ensure does not throw exception
@@ -202,8 +201,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
 
     @override_config({"limit_usage_by_mau": True})
     def test_get_or_create_user_mau_blocked(self):
-        # Type ignore: mypy doesn't like us assigning to methods.
-        self.store.get_monthly_active_count = Mock(  # type: ignore[assignment]
+        self.store.get_monthly_active_count = Mock(
             return_value=make_awaitable(self.lots_of_users)
         )
         self.get_failure(
@@ -211,8 +209,7 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
             ResourceLimitError,
         )
 
-        # Type ignore: mypy doesn't like us assigning to methods.
-        self.store.get_monthly_active_count = Mock(  # type: ignore[assignment]
+        self.store.get_monthly_active_count = Mock(
             return_value=make_awaitable(self.hs.config.server.max_mau_value)
         )
         self.get_failure(
diff --git a/tests/module_api/test_account_data_manager.py b/tests/module_api/test_account_data_manager.py
index bec018d9e7..89009bea8c 100644
--- a/tests/module_api/test_account_data_manager.py
+++ b/tests/module_api/test_account_data_manager.py
@@ -11,8 +11,12 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from twisted.test.proto_helpers import MemoryReactor
+
 from synapse.api.errors import SynapseError
 from synapse.rest import admin
+from synapse.server import HomeServer
+from synapse.util import Clock
 
 from tests.unittest import HomeserverTestCase
 
@@ -22,7 +26,9 @@ class ModuleApiTestCase(HomeserverTestCase):
         admin.register_servlets,
     ]
 
-    def prepare(self, reactor, clock, homeserver) -> None:
+    def prepare(
+        self, reactor: MemoryReactor, clock: Clock, homeserver: HomeServer
+    ) -> None:
         self._store = homeserver.get_datastores().main
         self._module_api = homeserver.get_module_api()
         self._account_data_mgr = self._module_api.account_data_manager
@@ -91,7 +97,7 @@ class ModuleApiTestCase(HomeserverTestCase):
         )
         with self.assertRaises(TypeError):
             # This throws an exception because it's a frozen dict.
-            the_data["wombat"] = False
+            the_data["wombat"] = False  # type: ignore[index]
 
     def test_put_global(self) -> None:
         """
@@ -143,15 +149,14 @@ class ModuleApiTestCase(HomeserverTestCase):
         with self.assertRaises(TypeError):
             # The account data type must be a string.
             self.get_success_or_raise(
-                self._module_api.account_data_manager.put_global(
-                    self.user_id, 42, {}  # type: ignore
-                )
+                self._module_api.account_data_manager.put_global(self.user_id, 42, {})  # type: ignore[arg-type]
             )
 
         with self.assertRaises(TypeError):
             # The account data dict must be a dict.
+            # noinspection PyTypeChecker
             self.get_success_or_raise(
                 self._module_api.account_data_manager.put_global(
-                    self.user_id, "test.data", 42  # type: ignore
+                    self.user_id, "test.data", 42  # type: ignore[arg-type]
                 )
             )
diff --git a/tests/replication/test_federation_sender_shard.py b/tests/replication/test_federation_sender_shard.py
index ba1a63c0d6..6104a55aa1 100644
--- a/tests/replication/test_federation_sender_shard.py
+++ b/tests/replication/test_federation_sender_shard.py
@@ -102,8 +102,8 @@ class FederationSenderTestCase(BaseMultiWorkerStreamTestCase):
         for i in range(20):
             server_name = "other_server_%d" % (i,)
             room = self.create_room_with_remote_server(user, token, server_name)
-            mock_client1.reset_mock()  # type: ignore[attr-defined]
-            mock_client2.reset_mock()  # type: ignore[attr-defined]
+            mock_client1.reset_mock()
+            mock_client2.reset_mock()
 
             self.create_and_send_event(room, UserID.from_string(user))
             self.replicate()
@@ -167,8 +167,8 @@ class FederationSenderTestCase(BaseMultiWorkerStreamTestCase):
         for i in range(20):
             server_name = "other_server_%d" % (i,)
             room = self.create_room_with_remote_server(user, token, server_name)
-            mock_client1.reset_mock()  # type: ignore[attr-defined]
-            mock_client2.reset_mock()  # type: ignore[attr-defined]
+            mock_client1.reset_mock()
+            mock_client2.reset_mock()
 
             self.get_success(
                 typing_handler.started_typing(
diff --git a/tests/test_utils/__init__.py b/tests/test_utils/__init__.py
index f05a373aa0..0d0d6faf0d 100644
--- a/tests/test_utils/__init__.py
+++ b/tests/test_utils/__init__.py
@@ -52,7 +52,7 @@ def make_awaitable(result: TV) -> Awaitable[TV]:
     This uses Futures as they can be awaited multiple times so can be returned
     to multiple callers.
     """
-    future = Future()  # type: ignore
+    future: Future[TV] = Future()
     future.set_result(result)
     return future
 
@@ -69,7 +69,7 @@ def setup_awaitable_errors() -> Callable[[], None]:
 
     # State shared between unraisablehook and check_for_unraisable_exceptions.
     unraisable_exceptions = []
-    orig_unraisablehook = sys.unraisablehook  # type: ignore
+    orig_unraisablehook = sys.unraisablehook
 
     def unraisablehook(unraisable):
         unraisable_exceptions.append(unraisable.exc_value)
@@ -78,11 +78,11 @@ def setup_awaitable_errors() -> Callable[[], None]:
         """
         A method to be used as a clean-up that fails a test-case if there are any new unraisable exceptions.
         """
-        sys.unraisablehook = orig_unraisablehook  # type: ignore
+        sys.unraisablehook = orig_unraisablehook
         if unraisable_exceptions:
             raise unraisable_exceptions.pop()
 
-    sys.unraisablehook = unraisablehook  # type: ignore
+    sys.unraisablehook = unraisablehook
 
     return cleanup
 
diff --git a/tests/test_utils/logging_setup.py b/tests/test_utils/logging_setup.py
index 51a197a8c6..9228454c9e 100644
--- a/tests/test_utils/logging_setup.py
+++ b/tests/test_utils/logging_setup.py
@@ -27,7 +27,7 @@ class ToTwistedHandler(logging.Handler):
     def emit(self, record):
         log_entry = self.format(record)
         log_level = record.levelname.lower().replace("warning", "warn")
-        self.tx_log.emit(  # type: ignore
+        self.tx_log.emit(
             twisted.logger.LogLevel.levelWithName(log_level), "{entry}", entry=log_entry
         )