Bugbear: Add Mutable Parameter fixes (#9682)

Part of #9366

Adds in fixes for B006 and B008, both relating to mutable parameter lint errors.

Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>

11 files changed, 68 insertions, 33 deletions

diff --git a/tests/http/federation/test_matrix_federation_agent.py b/tests/http/federation/test_matrix_federation_agent.py
index 4c56253da5..73e12ea6c3 100644
--- a/tests/http/federation/test_matrix_federation_agent.py
+++ b/tests/http/federation/test_matrix_federation_agent.py
@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
+from typing import Optional
 
 from mock import Mock
 
@@ -180,7 +181,11 @@ class MatrixFederationAgentTests(unittest.TestCase):
                 _check_logcontext(context)
 
     def _handle_well_known_connection(
-        self, client_factory, expected_sni, content, response_headers={}
+        self,
+        client_factory,
+        expected_sni,
+        content,
+        response_headers: Optional[dict] = None,
     ):
         """Handle an outgoing HTTPs connection: wire it up to a server, check that the
         request is for a .well-known, and send the response.
@@ -202,10 +207,12 @@ class MatrixFederationAgentTests(unittest.TestCase):
         self.assertEqual(
             request.requestHeaders.getRawHeaders(b"user-agent"), [b"test-agent"]
         )
-        self._send_well_known_response(request, content, headers=response_headers)
+        self._send_well_known_response(request, content, headers=response_headers or {})
         return well_known_server
 
-    def _send_well_known_response(self, request, content, headers={}):
+    def _send_well_known_response(
+        self, request, content, headers: Optional[dict] = None
+    ):
         """Check that an incoming request looks like a valid .well-known request, and
         send back the response.
         """
@@ -213,7 +220,7 @@ class MatrixFederationAgentTests(unittest.TestCase):
         self.assertEqual(request.path, b"/.well-known/matrix/server")
         self.assertEqual(request.requestHeaders.getRawHeaders(b"host"), [b"testserv"])
         # send back a response
-        for k, v in headers.items():
+        for k, v in (headers or {}).items():
             request.setHeader(k, v)
         request.write(content)
         request.finish()
diff --git a/tests/replication/_base.py b/tests/replication/_base.py
index 1d4a592862..aff19d9fb3 100644
--- a/tests/replication/_base.py
+++ b/tests/replication/_base.py
@@ -266,7 +266,7 @@ class BaseMultiWorkerStreamTestCase(unittest.HomeserverTestCase):
         return resource
 
     def make_worker_hs(
-        self, worker_app: str, extra_config: dict = {}, **kwargs
+        self, worker_app: str, extra_config: Optional[dict] = None, **kwargs
     ) -> HomeServer:
         """Make a new worker HS instance, correctly connecting replcation
         stream to the master HS.
@@ -283,7 +283,7 @@ class BaseMultiWorkerStreamTestCase(unittest.HomeserverTestCase):
 
         config = self._get_worker_hs_config()
         config["worker_app"] = worker_app
-        config.update(extra_config)
+        config.update(extra_config or {})
 
         worker_hs = self.setup_test_homeserver(
             homeserver_to_use=GenericWorkerServer,
diff --git a/tests/replication/slave/storage/test_events.py b/tests/replication/slave/storage/test_events.py
index 0ceb0f935c..333374b183 100644
--- a/tests/replication/slave/storage/test_events.py
+++ b/tests/replication/slave/storage/test_events.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
+from typing import Iterable, Optional
 
 from canonicaljson import encode_canonical_json
 
@@ -332,15 +333,18 @@ class SlavedEventStoreTestCase(BaseSlavedStoreTestCase):
         room_id=ROOM_ID,
         type="m.room.message",
         key=None,
-        internal={},
+        internal: Optional[dict] = None,
         depth=None,
-        prev_events=[],
-        auth_events=[],
-        prev_state=[],
+        prev_events: Optional[list] = None,
+        auth_events: Optional[list] = None,
+        prev_state: Optional[list] = None,
         redacts=None,
-        push_actions=[],
+        push_actions: Iterable = frozenset(),
         **content
     ):
+        prev_events = prev_events or []
+        auth_events = auth_events or []
+        prev_state = prev_state or []
 
         if depth is None:
             depth = self.event_id
@@ -369,7 +373,7 @@ class SlavedEventStoreTestCase(BaseSlavedStoreTestCase):
         if redacts is not None:
             event_dict["redacts"] = redacts
 
-        event = make_event_from_dict(event_dict, internal_metadata_dict=internal)
+        event = make_event_from_dict(event_dict, internal_metadata_dict=internal or {})
 
         self.event_id += 1
         state_handler = self.hs.get_state_handler()
diff --git a/tests/rest/client/v1/test_rooms.py b/tests/rest/client/v1/test_rooms.py
index ed65f645fc..715414a310 100644
--- a/tests/rest/client/v1/test_rooms.py
+++ b/tests/rest/client/v1/test_rooms.py
@@ -19,6 +19,7 @@
 """Tests REST events for /rooms paths."""
 
 import json
+from typing import Iterable
 from urllib import parse as urlparse
 
 from mock import Mock
@@ -207,7 +208,9 @@ class RoomPermissionsTestCase(RoomBase):
         )
         self.assertEquals(403, channel.code, msg=channel.result["body"])
 
-    def _test_get_membership(self, room=None, members=[], expect_code=None):
+    def _test_get_membership(
+        self, room=None, members: Iterable = frozenset(), expect_code=None
+    ):
         for member in members:
             path = "/rooms/%s/state/m.room.member/%s" % (room, member)
             channel = self.make_request("GET", path)
diff --git a/tests/rest/client/v1/utils.py b/tests/rest/client/v1/utils.py
index 946740aa5d..8a4dddae2b 100644
--- a/tests/rest/client/v1/utils.py
+++ b/tests/rest/client/v1/utils.py
@@ -132,7 +132,7 @@ class RestHelper:
         src: str,
         targ: str,
         membership: str,
-        extra_data: dict = {},
+        extra_data: Optional[dict] = None,
         tok: Optional[str] = None,
         expect_code: int = 200,
     ) -> None:
@@ -156,7 +156,7 @@ class RestHelper:
             path = path + "?access_token=%s" % tok
 
         data = {"membership": membership}
-        data.update(extra_data)
+        data.update(extra_data or {})
 
         channel = make_request(
             self.hs.get_reactor(),
@@ -187,7 +187,13 @@ class RestHelper:
         )
 
     def send_event(
-        self, room_id, type, content={}, txn_id=None, tok=None, expect_code=200
+        self,
+        room_id,
+        type,
+        content: Optional[dict] = None,
+        txn_id=None,
+        tok=None,
+        expect_code=200,
     ):
         if txn_id is None:
             txn_id = "m%s" % (str(time.time()))
@@ -201,7 +207,7 @@ class RestHelper:
             self.site,
             "PUT",
             path,
-            json.dumps(content).encode("utf8"),
+            json.dumps(content or {}).encode("utf8"),
         )
 
         assert (
diff --git a/tests/rest/client/v2_alpha/test_relations.py b/tests/rest/client/v2_alpha/test_relations.py
index e7bb5583fc..21ee436b91 100644
--- a/tests/rest/client/v2_alpha/test_relations.py
+++ b/tests/rest/client/v2_alpha/test_relations.py
@@ -16,6 +16,7 @@
 import itertools
 import json
 import urllib
+from typing import Optional
 
 from synapse.api.constants import EventTypes, RelationTypes
 from synapse.rest import admin
@@ -681,7 +682,7 @@ class RelationsTestCase(unittest.HomeserverTestCase):
         relation_type,
         event_type,
         key=None,
-        content={},
+        content: Optional[dict] = None,
         access_token=None,
         parent_id=None,
     ):
@@ -713,7 +714,7 @@ class RelationsTestCase(unittest.HomeserverTestCase):
             "POST",
             "/_matrix/client/unstable/rooms/%s/send_relation/%s/%s/%s%s"
             % (self.room, original_id, relation_type, event_type, query),
-            json.dumps(content).encode("utf-8"),
+            json.dumps(content or {}).encode("utf-8"),
             access_token=access_token,
         )
         return channel
diff --git a/tests/storage/test_id_generators.py b/tests/storage/test_id_generators.py
index aad6bc907e..6c389fe9ac 100644
--- a/tests/storage/test_id_generators.py
+++ b/tests/storage/test_id_generators.py
@@ -12,6 +12,8 @@
 # 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 typing import List, Optional
+
 from synapse.storage.database import DatabasePool
 from synapse.storage.engines import IncorrectDatabaseSetup
 from synapse.storage.util.id_generators import MultiWriterIdGenerator
@@ -43,7 +45,7 @@ class MultiWriterIdGeneratorTestCase(HomeserverTestCase):
         )
 
     def _create_id_generator(
-        self, instance_name="master", writers=["master"]
+        self, instance_name="master", writers: Optional[List[str]] = None
     ) -> MultiWriterIdGenerator:
         def _create(conn):
             return MultiWriterIdGenerator(
@@ -53,7 +55,7 @@ class MultiWriterIdGeneratorTestCase(HomeserverTestCase):
                 instance_name=instance_name,
                 tables=[("foobar", "instance_name", "stream_id")],
                 sequence_name="foobar_seq",
-                writers=writers,
+                writers=writers or ["master"],
             )
 
         return self.get_success_or_raise(self.db_pool.runWithConnection(_create))
@@ -476,7 +478,7 @@ class BackwardsMultiWriterIdGeneratorTestCase(HomeserverTestCase):
         )
 
     def _create_id_generator(
-        self, instance_name="master", writers=["master"]
+        self, instance_name="master", writers: Optional[List[str]] = None
     ) -> MultiWriterIdGenerator:
         def _create(conn):
             return MultiWriterIdGenerator(
@@ -486,7 +488,7 @@ class BackwardsMultiWriterIdGeneratorTestCase(HomeserverTestCase):
                 instance_name=instance_name,
                 tables=[("foobar", "instance_name", "stream_id")],
                 sequence_name="foobar_seq",
-                writers=writers,
+                writers=writers or ["master"],
                 positive=False,
             )
 
@@ -612,7 +614,7 @@ class MultiTableMultiWriterIdGeneratorTestCase(HomeserverTestCase):
         )
 
     def _create_id_generator(
-        self, instance_name="master", writers=["master"]
+        self, instance_name="master", writers: Optional[List[str]] = None
     ) -> MultiWriterIdGenerator:
         def _create(conn):
             return MultiWriterIdGenerator(
@@ -625,7 +627,7 @@ class MultiTableMultiWriterIdGeneratorTestCase(HomeserverTestCase):
                     ("foobar2", "instance_name", "stream_id"),
                 ],
                 sequence_name="foobar_seq",
-                writers=writers,
+                writers=writers or ["master"],
             )
 
         return self.get_success_or_raise(self.db_pool.runWithConnection(_create))
diff --git a/tests/storage/test_redaction.py b/tests/storage/test_redaction.py
index 2622207639..2d2f58903c 100644
--- a/tests/storage/test_redaction.py
+++ b/tests/storage/test_redaction.py
@@ -12,6 +12,7 @@
 # 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 typing import Optional
 
 from canonicaljson import json
 
@@ -47,10 +48,15 @@ class RedactionTestCase(unittest.HomeserverTestCase):
         self.depth = 1
 
     def inject_room_member(
-        self, room, user, membership, replaces_state=None, extra_content={}
+        self,
+        room,
+        user,
+        membership,
+        replaces_state=None,
+        extra_content: Optional[dict] = None,
     ):
         content = {"membership": membership}
-        content.update(extra_content)
+        content.update(extra_content or {})
         builder = self.event_builder_factory.for_room_version(
             RoomVersions.V1,
             {
diff --git a/tests/test_state.py b/tests/test_state.py
index 6227a3ba95..1d2019699d 100644
--- a/tests/test_state.py
+++ b/tests/test_state.py
@@ -12,6 +12,7 @@
 # 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 typing import List, Optional
 
 from mock import Mock
 
@@ -37,7 +38,7 @@ def create_event(
     state_key=None,
     depth=2,
     event_id=None,
-    prev_events=[],
+    prev_events: Optional[List[str]] = None,
     **kwargs
 ):
     global _next_event_id
@@ -58,7 +59,7 @@ def create_event(
         "sender": "@user_id:example.com",
         "room_id": "!room_id:example.com",
         "depth": depth,
-        "prev_events": prev_events,
+        "prev_events": prev_events or [],
     }
 
     if state_key is not None:
diff --git a/tests/test_visibility.py b/tests/test_visibility.py
index 510b630114..1b4dd47a82 100644
--- a/tests/test_visibility.py
+++ b/tests/test_visibility.py
@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
+from typing import Optional
 
 from mock import Mock
 
@@ -147,9 +148,11 @@ class FilterEventsForServerTestCase(tests.unittest.TestCase):
         return event
 
     @defer.inlineCallbacks
-    def inject_room_member(self, user_id, membership="join", extra_content={}):
+    def inject_room_member(
+        self, user_id, membership="join", extra_content: Optional[dict] = None
+    ):
         content = {"membership": membership}
-        content.update(extra_content)
+        content.update(extra_content or {})
         builder = self.event_builder_factory.for_room_version(
             RoomVersions.V1,
             {
diff --git a/tests/util/test_ratelimitutils.py b/tests/util/test_ratelimitutils.py
index 4d1aee91d5..3fed55090a 100644
--- a/tests/util/test_ratelimitutils.py
+++ b/tests/util/test_ratelimitutils.py
@@ -12,6 +12,8 @@
 # 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 typing import Optional
+
 from synapse.config.homeserver import HomeServerConfig
 from synapse.util.ratelimitutils import FederationRateLimiter
 
@@ -89,9 +91,9 @@ def _await_resolution(reactor, d):
     return (reactor.seconds() - start_time) * 1000
 
 
-def build_rc_config(settings={}):
+def build_rc_config(settings: Optional[dict] = None):
     config_dict = default_config("test")
-    config_dict.update(settings)
+    config_dict.update(settings or {})
     config = HomeServerConfig()
     config.parse_config_dict(config_dict, "", "")
     return config.rc_federation