Update black to 19.10b0 (#6304)

* update version of black and also fix the mypy config being overridden

41 files changed, 191 insertions, 166 deletions

diff --git a/changelog.d/6304.misc b/changelog.d/6304.misc
new file mode 100644
index 0000000000..20372b4f7c
--- /dev/null
+++ b/changelog.d/6304.misc
@@ -0,0 +1 @@
+Update the version of black used to 19.10b0.
diff --git a/contrib/experiments/test_messaging.py b/contrib/experiments/test_messaging.py
index 6b22400a60..3bbbcfa1b4 100644
--- a/contrib/experiments/test_messaging.py
+++ b/contrib/experiments/test_messaging.py
@@ -78,7 +78,7 @@ class InputOutput(object):
             m = re.match("^join (\S+)$", line)
             if m:
                 # The `sender` wants to join a room.
-                room_name, = m.groups()
+                (room_name,) = m.groups()
                 self.print_line("%s joining %s" % (self.user, room_name))
                 self.server.join_room(room_name, self.user, self.user)
                 # self.print_line("OK.")
@@ -105,7 +105,7 @@ class InputOutput(object):
             m = re.match("^backfill (\S+)$", line)
             if m:
                 # we want to backfill a room
-                room_name, = m.groups()
+                (room_name,) = m.groups()
                 self.print_line("backfill %s" % room_name)
                 self.server.backfill(room_name)
                 return
diff --git a/mypy.ini b/mypy.ini
index ffadaddc0b..1d77c0ecc8 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -1,8 +1,11 @@
 [mypy]
-namespace_packages=True
-plugins=mypy_zope:plugin
-follow_imports=skip
-mypy_path=stubs
+namespace_packages = True
+plugins = mypy_zope:plugin
+follow_imports = normal
+check_untyped_defs = True
+show_error_codes = True
+show_traceback = True
+mypy_path = stubs
 
 [mypy-zope]
 ignore_missing_imports = True
diff --git a/synapse/federation/sender/per_destination_queue.py b/synapse/federation/sender/per_destination_queue.py
index cc75c39476..b754a09d7a 100644
--- a/synapse/federation/sender/per_destination_queue.py
+++ b/synapse/federation/sender/per_destination_queue.py
@@ -192,15 +192,16 @@ class PerDestinationQueue(object):
                 # We have to keep 2 free slots for presence and rr_edus
                 limit = MAX_EDUS_PER_TRANSACTION - 2
 
-                device_update_edus, dev_list_id = (
-                    yield self._get_device_update_edus(limit)
+                device_update_edus, dev_list_id = yield self._get_device_update_edus(
+                    limit
                 )
 
                 limit -= len(device_update_edus)
 
-                to_device_edus, device_stream_id = (
-                    yield self._get_to_device_message_edus(limit)
-                )
+                (
+                    to_device_edus,
+                    device_stream_id,
+                ) = yield self._get_to_device_message_edus(limit)
 
                 pending_edus = device_update_edus + to_device_edus
 
diff --git a/synapse/handlers/account_data.py b/synapse/handlers/account_data.py
index 38bc67191c..2d7e6df6e4 100644
--- a/synapse/handlers/account_data.py
+++ b/synapse/handlers/account_data.py
@@ -38,9 +38,10 @@ class AccountDataEventSource(object):
                 {"type": "m.tag", "content": {"tags": room_tags}, "room_id": room_id}
             )
 
-        account_data, room_account_data = (
-            yield self.store.get_updated_account_data_for_user(user_id, last_stream_id)
-        )
+        (
+            account_data,
+            room_account_data,
+        ) = yield self.store.get_updated_account_data_for_user(user_id, last_stream_id)
 
         for account_data_type, content in account_data.items():
             results.append({"type": account_data_type, "content": content})
diff --git a/synapse/handlers/appservice.py b/synapse/handlers/appservice.py
index 3e9b298154..fe62f78e67 100644
--- a/synapse/handlers/appservice.py
+++ b/synapse/handlers/appservice.py
@@ -73,7 +73,10 @@ class ApplicationServicesHandler(object):
             try:
                 limit = 100
                 while True:
-                    upper_bound, events = yield self.store.get_new_events_for_appservice(
+                    (
+                        upper_bound,
+                        events,
+                    ) = yield self.store.get_new_events_for_appservice(
                         self.current_max, limit
                     )
 
diff --git a/synapse/handlers/e2e_keys.py b/synapse/handlers/e2e_keys.py
index 5ea54f60be..0449034a4e 100644
--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -119,9 +119,10 @@ class E2eKeysHandler(object):
                 else:
                     query_list.append((user_id, None))
 
-            user_ids_not_in_cache, remote_results = (
-                yield self.store.get_user_devices_from_cache(query_list)
-            )
+            (
+                user_ids_not_in_cache,
+                remote_results,
+            ) = yield self.store.get_user_devices_from_cache(query_list)
             for user_id, devices in iteritems(remote_results):
                 user_devices = results.setdefault(user_id, {})
                 for device_id, device in iteritems(devices):
@@ -688,17 +689,21 @@ class E2eKeysHandler(object):
 
         try:
             # get our self-signing key to verify the signatures
-            _, self_signing_key_id, self_signing_verify_key = yield self._get_e2e_cross_signing_verify_key(
-                user_id, "self_signing"
-            )
+            (
+                _,
+                self_signing_key_id,
+                self_signing_verify_key,
+            ) = yield self._get_e2e_cross_signing_verify_key(user_id, "self_signing")
 
             # get our master key, since we may have received a signature of it.
             # We need to fetch it here so that we know what its key ID is, so
             # that we can check if a signature that was sent is a signature of
             # the master key or of a device
-            master_key, _, master_verify_key = yield self._get_e2e_cross_signing_verify_key(
-                user_id, "master"
-            )
+            (
+                master_key,
+                _,
+                master_verify_key,
+            ) = yield self._get_e2e_cross_signing_verify_key(user_id, "master")
 
             # fetch our stored devices.  This is used to 1. verify
             # signatures on the master key, and 2. to compare with what
@@ -838,9 +843,11 @@ class E2eKeysHandler(object):
 
         try:
             # get our user-signing key to verify the signatures
-            user_signing_key, user_signing_key_id, user_signing_verify_key = yield self._get_e2e_cross_signing_verify_key(
-                user_id, "user_signing"
-            )
+            (
+                user_signing_key,
+                user_signing_key_id,
+                user_signing_verify_key,
+            ) = yield self._get_e2e_cross_signing_verify_key(user_id, "user_signing")
         except SynapseError as e:
             failure = _exception_to_failure(e)
             for user, devicemap in signatures.items():
@@ -859,7 +866,11 @@ class E2eKeysHandler(object):
             try:
                 # get the target user's master key, to make sure it matches
                 # what was sent
-                master_key, master_key_id, _ = yield self._get_e2e_cross_signing_verify_key(
+                (
+                    master_key,
+                    master_key_id,
+                    _,
+                ) = yield self._get_e2e_cross_signing_verify_key(
                     target_user, "master", user_id
                 )
 
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index d2d9f8c26a..a932d3085f 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -352,10 +352,11 @@ class FederationHandler(BaseHandler):
                             # note that if any of the missing prevs share missing state or
                             # auth events, the requests to fetch those events are deduped
                             # by the get_pdu_cache in federation_client.
-                            remote_state, got_auth_chain = (
-                                yield self.federation_client.get_state_for_room(
-                                    origin, room_id, p
-                                )
+                            (
+                                remote_state,
+                                got_auth_chain,
+                            ) = yield self.federation_client.get_state_for_room(
+                                origin, room_id, p
                             )
 
                             # we want the state *after* p; get_state_for_room returns the
diff --git a/synapse/handlers/initial_sync.py b/synapse/handlers/initial_sync.py
index 49c9e031f9..81dce96f4b 100644
--- a/synapse/handlers/initial_sync.py
+++ b/synapse/handlers/initial_sync.py
@@ -128,8 +128,8 @@ class InitialSyncHandler(BaseHandler):
 
         tags_by_room = yield self.store.get_tags_for_user(user_id)
 
-        account_data, account_data_by_room = (
-            yield self.store.get_account_data_for_user(user_id)
+        account_data, account_data_by_room = yield self.store.get_account_data_for_user(
+            user_id
         )
 
         public_room_ids = yield self.store.get_public_room_ids()
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 0d546d2487..d682dc2b7a 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -76,9 +76,10 @@ class MessageHandler(object):
         Raises:
             SynapseError if something went wrong.
         """
-        membership, membership_event_id = yield self.auth.check_in_room_or_world_readable(
-            room_id, user_id
-        )
+        (
+            membership,
+            membership_event_id,
+        ) = yield self.auth.check_in_room_or_world_readable(room_id, user_id)
 
         if membership == Membership.JOIN:
             data = yield self.state.get_current_state(room_id, event_type, state_key)
@@ -153,9 +154,10 @@ class MessageHandler(object):
                     % (user_id, room_id, at_token),
                 )
         else:
-            membership, membership_event_id = (
-                yield self.auth.check_in_room_or_world_readable(room_id, user_id)
-            )
+            (
+                membership,
+                membership_event_id,
+            ) = yield self.auth.check_in_room_or_world_readable(room_id, user_id)
 
             if membership == Membership.JOIN:
                 state_ids = yield self.store.get_filtered_current_state_ids(
diff --git a/synapse/handlers/pagination.py b/synapse/handlers/pagination.py
index b7185fe7a0..97f15a1c32 100644
--- a/synapse/handlers/pagination.py
+++ b/synapse/handlers/pagination.py
@@ -212,9 +212,10 @@ class PaginationHandler(object):
         source_config = pagin_config.get_source_config("room")
 
         with (yield self.pagination_lock.read(room_id)):
-            membership, member_event_id = yield self.auth.check_in_room_or_world_readable(
-                room_id, user_id
-            )
+            (
+                membership,
+                member_event_id,
+            ) = yield self.auth.check_in_room_or_world_readable(room_id, user_id)
 
             if source_config.direction == "b":
                 # if we're going backwards, we might need to backfill. This
@@ -297,10 +298,8 @@ class PaginationHandler(object):
         }
 
         if state:
-            chunk["state"] = (
-                yield self._event_serializer.serialize_events(
-                    state, time_now, as_client_event=as_client_event
-                )
+            chunk["state"] = yield self._event_serializer.serialize_events(
+                state, time_now, as_client_event=as_client_event
             )
 
         return chunk
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index 53410f120b..cff6b0d375 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -396,8 +396,8 @@ class RegistrationHandler(BaseHandler):
             room_id = room_identifier
         elif RoomAlias.is_valid(room_identifier):
             room_alias = RoomAlias.from_string(room_identifier)
-            room_id, remote_room_hosts = (
-                yield room_member_handler.lookup_room_alias(room_alias)
+            room_id, remote_room_hosts = yield room_member_handler.lookup_room_alias(
+                room_alias
             )
             room_id = room_id.to_string()
         else:
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 650bd28abb..0182e5b432 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -147,21 +147,22 @@ class RoomCreationHandler(BaseHandler):
 
         # we create and auth the tombstone event before properly creating the new
         # room, to check our user has perms in the old room.
-        tombstone_event, tombstone_context = (
-            yield self.event_creation_handler.create_event(
-                requester,
-                {
-                    "type": EventTypes.Tombstone,
-                    "state_key": "",
-                    "room_id": old_room_id,
-                    "sender": user_id,
-                    "content": {
-                        "body": "This room has been replaced",
-                        "replacement_room": new_room_id,
-                    },
+        (
+            tombstone_event,
+            tombstone_context,
+        ) = yield self.event_creation_handler.create_event(
+            requester,
+            {
+                "type": EventTypes.Tombstone,
+                "state_key": "",
+                "room_id": old_room_id,
+                "sender": user_id,
+                "content": {
+                    "body": "This room has been replaced",
+                    "replacement_room": new_room_id,
                 },
-                token_id=requester.access_token_id,
-            )
+            },
+            token_id=requester.access_token_id,
         )
         old_room_version = yield self.store.get_room_version(old_room_id)
         yield self.auth.check_from_context(
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 380e2fad5e..9a940d2c05 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -759,22 +759,25 @@ class RoomMemberHandler(object):
         if room_avatar_event:
             room_avatar_url = room_avatar_event.content.get("url", "")
 
-        token, public_keys, fallback_public_key, display_name = (
-            yield self.identity_handler.ask_id_server_for_third_party_invite(
-                requester=requester,
-                id_server=id_server,
-                medium=medium,
-                address=address,
-                room_id=room_id,
-                inviter_user_id=user.to_string(),
-                room_alias=canonical_room_alias,
-                room_avatar_url=room_avatar_url,
-                room_join_rules=room_join_rules,
-                room_name=room_name,
-                inviter_display_name=inviter_display_name,
-                inviter_avatar_url=inviter_avatar_url,
-                id_access_token=id_access_token,
-            )
+        (
+            token,
+            public_keys,
+            fallback_public_key,
+            display_name,
+        ) = yield self.identity_handler.ask_id_server_for_third_party_invite(
+            requester=requester,
+            id_server=id_server,
+            medium=medium,
+            address=address,
+            room_id=room_id,
+            inviter_user_id=user.to_string(),
+            room_alias=canonical_room_alias,
+            room_avatar_url=room_avatar_url,
+            room_join_rules=room_join_rules,
+            room_name=room_name,
+            inviter_display_name=inviter_display_name,
+            inviter_avatar_url=inviter_avatar_url,
+            id_access_token=id_access_token,
         )
 
         yield self.event_creation_handler.create_and_send_nonmember_event(
diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py
index f4d8a60774..56ed262a1f 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -396,15 +396,11 @@ class SearchHandler(BaseHandler):
         time_now = self.clock.time_msec()
 
         for context in contexts.values():
-            context["events_before"] = (
-                yield self._event_serializer.serialize_events(
-                    context["events_before"], time_now
-                )
+            context["events_before"] = yield self._event_serializer.serialize_events(
+                context["events_before"], time_now
             )
-            context["events_after"] = (
-                yield self._event_serializer.serialize_events(
-                    context["events_after"], time_now
-                )
+            context["events_after"] = yield self._event_serializer.serialize_events(
+                context["events_after"], time_now
             )
 
         state_results = {}
diff --git a/synapse/handlers/stats.py b/synapse/handlers/stats.py
index 26bc276692..7f7d56390e 100644
--- a/synapse/handlers/stats.py
+++ b/synapse/handlers/stats.py
@@ -108,7 +108,10 @@ class StatsHandler(StateDeltasHandler):
                 user_deltas = {}
 
             # Then count deltas for total_events and total_event_bytes.
-            room_count, user_count = yield self.store.get_changes_room_total_events_and_bytes(
+            (
+                room_count,
+                user_count,
+            ) = yield self.store.get_changes_room_total_events_and_bytes(
                 self.pos, max_pos
             )
 
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 43a082dcda..b536d410e5 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -1206,10 +1206,11 @@ class SyncHandler(object):
         since_token = sync_result_builder.since_token
 
         if since_token and not sync_result_builder.full_state:
-            account_data, account_data_by_room = (
-                yield self.store.get_updated_account_data_for_user(
-                    user_id, since_token.account_data_key
-                )
+            (
+                account_data,
+                account_data_by_room,
+            ) = yield self.store.get_updated_account_data_for_user(
+                user_id, since_token.account_data_key
             )
 
             push_rules_changed = yield self.store.have_push_rules_changed_for_user(
@@ -1221,9 +1222,10 @@ class SyncHandler(object):
                     sync_config.user
                 )
         else:
-            account_data, account_data_by_room = (
-                yield self.store.get_account_data_for_user(sync_config.user.to_string())
-            )
+            (
+                account_data,
+                account_data_by_room,
+            ) = yield self.store.get_account_data_for_user(sync_config.user.to_string())
 
             account_data["m.push_rules"] = yield self.push_rules_for_user(
                 sync_config.user
diff --git a/synapse/logging/_structured.py b/synapse/logging/_structured.py
index 3220e985a9..334ddaf39a 100644
--- a/synapse/logging/_structured.py
+++ b/synapse/logging/_structured.py
@@ -185,7 +185,7 @@ DEFAULT_LOGGERS = {"synapse": {"level": "INFO"}}
 
 
 def parse_drain_configs(
-    drains: dict
+    drains: dict,
 ) -> typing.Generator[DrainConfiguration, None, None]:
     """
     Parse the drain configurations.
diff --git a/synapse/push/bulk_push_rule_evaluator.py b/synapse/push/bulk_push_rule_evaluator.py
index 2bbdd11941..1ba7bcd4d8 100644
--- a/synapse/push/bulk_push_rule_evaluator.py
+++ b/synapse/push/bulk_push_rule_evaluator.py
@@ -149,9 +149,10 @@ class BulkPushRuleEvaluator(object):
 
         room_members = yield self.store.get_joined_users_from_context(event, context)
 
-        (power_levels, sender_power_level) = (
-            yield self._get_power_levels_and_sender_level(event, context)
-        )
+        (
+            power_levels,
+            sender_power_level,
+        ) = yield self._get_power_levels_and_sender_level(event, context)
 
         evaluator = PushRuleEvaluatorForEvent(
             event, len(room_members), sender_power_level, power_levels
diff --git a/synapse/push/emailpusher.py b/synapse/push/emailpusher.py
index 42e5b0c0a5..8c818a86bf 100644
--- a/synapse/push/emailpusher.py
+++ b/synapse/push/emailpusher.py
@@ -234,14 +234,12 @@ class EmailPusher(object):
             return
 
         self.last_stream_ordering = last_stream_ordering
-        pusher_still_exists = (
-            yield self.store.update_pusher_last_stream_ordering_and_success(
-                self.app_id,
-                self.email,
-                self.user_id,
-                last_stream_ordering,
-                self.clock.time_msec(),
-            )
+        pusher_still_exists = yield self.store.update_pusher_last_stream_ordering_and_success(
+            self.app_id,
+            self.email,
+            self.user_id,
+            last_stream_ordering,
+            self.clock.time_msec(),
         )
         if not pusher_still_exists:
             # The pusher has been deleted while we were processing, so
diff --git a/synapse/push/httppusher.py b/synapse/push/httppusher.py
index 9a1bb64887..7dde2ad055 100644
--- a/synapse/push/httppusher.py
+++ b/synapse/push/httppusher.py
@@ -211,14 +211,12 @@ class HttpPusher(object):
                 http_push_processed_counter.inc()
                 self.backoff_delay = HttpPusher.INITIAL_BACKOFF_SEC
                 self.last_stream_ordering = push_action["stream_ordering"]
-                pusher_still_exists = (
-                    yield self.store.update_pusher_last_stream_ordering_and_success(
-                        self.app_id,
-                        self.pushkey,
-                        self.user_id,
-                        self.last_stream_ordering,
-                        self.clock.time_msec(),
-                    )
+                pusher_still_exists = yield self.store.update_pusher_last_stream_ordering_and_success(
+                    self.app_id,
+                    self.pushkey,
+                    self.user_id,
+                    self.last_stream_ordering,
+                    self.clock.time_msec(),
                 )
                 if not pusher_still_exists:
                     # The pusher has been deleted while we were processing, so
diff --git a/synapse/push/pusherpool.py b/synapse/push/pusherpool.py
index 08e840fdc2..0f6992202d 100644
--- a/synapse/push/pusherpool.py
+++ b/synapse/push/pusherpool.py
@@ -103,9 +103,7 @@ class PusherPool:
         # create the pusher setting last_stream_ordering to the current maximum
         # stream ordering in event_push_actions, so it will process
         # pushes from this point onwards.
-        last_stream_ordering = (
-            yield self.store.get_latest_push_action_stream_ordering()
-        )
+        last_stream_ordering = yield self.store.get_latest_push_action_stream_ordering()
 
         yield self.store.add_pusher(
             user_id=user_id,
diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 39a5c5e9de..00a7dd6d09 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -203,10 +203,11 @@ class LoginRestServlet(RestServlet):
                 address = address.lower()
 
             # Check for login providers that support 3pid login types
-            canonical_user_id, callback_3pid = (
-                yield self.auth_handler.check_password_provider_3pid(
-                    medium, address, login_submission["password"]
-                )
+            (
+                canonical_user_id,
+                callback_3pid,
+            ) = yield self.auth_handler.check_password_provider_3pid(
+                medium, address, login_submission["password"]
             )
             if canonical_user_id:
                 # Authentication through password provider and 3pid succeeded
@@ -280,8 +281,8 @@ class LoginRestServlet(RestServlet):
     def do_token_login(self, login_submission):
         token = login_submission["token"]
         auth_handler = self.auth_handler
-        user_id = (
-            yield auth_handler.validate_short_term_login_token_and_get_user_id(token)
+        user_id = yield auth_handler.validate_short_term_login_token_and_get_user_id(
+            token
         )
 
         result = yield self._register_device_with_callback(user_id, login_submission)
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 332d7138b1..f26eae794c 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -148,7 +148,7 @@ class PasswordResetSubmitTokenServlet(RestServlet):
         self.clock = hs.get_clock()
         self.store = hs.get_datastore()
         if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
-            self.failure_email_template, = load_jinja2_templates(
+            (self.failure_email_template,) = load_jinja2_templates(
                 self.config.email_template_dir,
                 [self.config.email_password_reset_template_failure_html],
             )
@@ -479,7 +479,7 @@ class AddThreepidEmailSubmitTokenServlet(RestServlet):
         self.clock = hs.get_clock()
         self.store = hs.get_datastore()
         if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
-            self.failure_email_template, = load_jinja2_templates(
+            (self.failure_email_template,) = load_jinja2_templates(
                 self.config.email_template_dir,
                 [self.config.email_add_threepid_template_failure_html],
             )
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index 6c7d25d411..91db923814 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -247,13 +247,13 @@ class RegistrationSubmitTokenServlet(RestServlet):
         self.store = hs.get_datastore()
 
         if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
-            self.failure_email_template, = load_jinja2_templates(
+            (self.failure_email_template,) = load_jinja2_templates(
                 self.config.email_template_dir,
                 [self.config.email_registration_template_failure_html],
             )
 
         if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
-            self.failure_email_template, = load_jinja2_templates(
+            (self.failure_email_template,) = load_jinja2_templates(
                 self.config.email_template_dir,
                 [self.config.email_registration_template_failure_html],
             )
diff --git a/synapse/rest/key/v2/remote_key_resource.py b/synapse/rest/key/v2/remote_key_resource.py
index 55580bc59e..e7fc3f0431 100644
--- a/synapse/rest/key/v2/remote_key_resource.py
+++ b/synapse/rest/key/v2/remote_key_resource.py
@@ -102,7 +102,7 @@ class RemoteKey(DirectServeResource):
     @wrap_json_request_handler
     async def _async_render_GET(self, request):
         if len(request.postpath) == 1:
-            server, = request.postpath
+            (server,) = request.postpath
             query = {server.decode("ascii"): {}}
         elif len(request.postpath) == 2:
             server, key_id = request.postpath
diff --git a/synapse/server.pyi b/synapse/server.pyi
index 16f8f6b573..83d1f11283 100644
--- a/synapse/server.pyi
+++ b/synapse/server.pyi
@@ -39,7 +39,7 @@ class HomeServer(object):
     def get_state_resolution_handler(self) -> synapse.state.StateResolutionHandler:
         pass
     def get_deactivate_account_handler(
-        self
+        self,
     ) -> synapse.handlers.deactivate_account.DeactivateAccountHandler:
         pass
     def get_room_creation_handler(self) -> synapse.handlers.room.RoomCreationHandler:
@@ -47,32 +47,32 @@ class HomeServer(object):
     def get_room_member_handler(self) -> synapse.handlers.room_member.RoomMemberHandler:
         pass
     def get_event_creation_handler(
-        self
+        self,
     ) -> synapse.handlers.message.EventCreationHandler:
         pass
     def get_set_password_handler(
-        self
+        self,
     ) -> synapse.handlers.set_password.SetPasswordHandler:
         pass
     def get_federation_sender(self) -> synapse.federation.sender.FederationSender:
         pass
     def get_federation_transport_client(
-        self
+        self,
     ) -> synapse.federation.transport.client.TransportLayerClient:
         pass
     def get_media_repository_resource(
-        self
+        self,
     ) -> synapse.rest.media.v1.media_repository.MediaRepositoryResource:
         pass
     def get_media_repository(
-        self
+        self,
     ) -> synapse.rest.media.v1.media_repository.MediaRepository:
         pass
     def get_server_notices_manager(
-        self
+        self,
     ) -> synapse.server_notices.server_notices_manager.ServerNoticesManager:
         pass
     def get_server_notices_sender(
-        self
+        self,
     ) -> synapse.server_notices.server_notices_sender.ServerNoticesSender:
         pass
diff --git a/synapse/storage/data_stores/main/__init__.py b/synapse/storage/data_stores/main/__init__.py
index b185ba0b3e..60ae01d972 100644
--- a/synapse/storage/data_stores/main/__init__.py
+++ b/synapse/storage/data_stores/main/__init__.py
@@ -317,7 +317,7 @@ class DataStore(
             ) u
         """
         txn.execute(sql, (time_from,))
-        count, = txn.fetchone()
+        (count,) = txn.fetchone()
         return count
 
     def count_r30_users(self):
@@ -396,7 +396,7 @@ class DataStore(
 
             txn.execute(sql, (thirty_days_ago_in_secs, thirty_days_ago_in_secs))
 
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             results["all"] = count
 
             return results
diff --git a/synapse/storage/data_stores/main/event_push_actions.py b/synapse/storage/data_stores/main/event_push_actions.py
index 22025effbc..04ce21ac66 100644
--- a/synapse/storage/data_stores/main/event_push_actions.py
+++ b/synapse/storage/data_stores/main/event_push_actions.py
@@ -863,7 +863,7 @@ class EventPushActionsStore(EventPushActionsWorkerStore):
         )
         stream_row = txn.fetchone()
         if stream_row:
-            offset_stream_ordering, = stream_row
+            (offset_stream_ordering,) = stream_row
             rotate_to_stream_ordering = min(
                 self.stream_ordering_day_ago, offset_stream_ordering
             )
diff --git a/synapse/storage/data_stores/main/events.py b/synapse/storage/data_stores/main/events.py
index 64a8a05279..aafc2007d3 100644
--- a/synapse/storage/data_stores/main/events.py
+++ b/synapse/storage/data_stores/main/events.py
@@ -1125,7 +1125,7 @@ class EventsStore(
                 AND stream_ordering > ?
             """
             txn.execute(sql, (self.stream_ordering_day_ago,))
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         ret = yield self.runInteraction("count_messages", _count_messages)
@@ -1146,7 +1146,7 @@ class EventsStore(
             """
 
             txn.execute(sql, (like_clause, self.stream_ordering_day_ago))
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         ret = yield self.runInteraction("count_daily_sent_messages", _count_messages)
@@ -1161,7 +1161,7 @@ class EventsStore(
                 AND stream_ordering > ?
             """
             txn.execute(sql, (self.stream_ordering_day_ago,))
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         ret = yield self.runInteraction("count_daily_active_rooms", _count)
@@ -1646,7 +1646,7 @@ class EventsStore(
         """,
             (room_id,),
         )
-        min_depth, = txn.fetchone()
+        (min_depth,) = txn.fetchone()
 
         logger.info("[purge] updating room_depth to %d", min_depth)
 
diff --git a/synapse/storage/data_stores/main/events_bg_updates.py b/synapse/storage/data_stores/main/events_bg_updates.py
index 31ea6f917f..51352b9966 100644
--- a/synapse/storage/data_stores/main/events_bg_updates.py
+++ b/synapse/storage/data_stores/main/events_bg_updates.py
@@ -438,7 +438,7 @@ class EventsBackgroundUpdatesStore(BackgroundUpdateStore):
             if not rows:
                 return 0
 
-            upper_event_id, = rows[-1]
+            (upper_event_id,) = rows[-1]
 
             # Update the redactions with the received_ts.
             #
diff --git a/synapse/storage/data_stores/main/group_server.py b/synapse/storage/data_stores/main/group_server.py
index aeae5a2b28..b3a2771f1b 100644
--- a/synapse/storage/data_stores/main/group_server.py
+++ b/synapse/storage/data_stores/main/group_server.py
@@ -249,7 +249,7 @@ class GroupServerStore(SQLBaseStore):
                 WHERE group_id = ? AND category_id = ?
             """
             txn.execute(sql, (group_id, category_id))
-            order, = txn.fetchone()
+            (order,) = txn.fetchone()
 
         if existing:
             to_update = {}
@@ -509,7 +509,7 @@ class GroupServerStore(SQLBaseStore):
                 WHERE group_id = ? AND role_id = ?
             """
             txn.execute(sql, (group_id, role_id))
-            order, = txn.fetchone()
+            (order,) = txn.fetchone()
 
         if existing:
             to_update = {}
diff --git a/synapse/storage/data_stores/main/monthly_active_users.py b/synapse/storage/data_stores/main/monthly_active_users.py
index e6ee1e4aaa..b41c3d317a 100644
--- a/synapse/storage/data_stores/main/monthly_active_users.py
+++ b/synapse/storage/data_stores/main/monthly_active_users.py
@@ -171,7 +171,7 @@ class MonthlyActiveUsersStore(SQLBaseStore):
             sql = "SELECT COALESCE(count(*), 0) FROM monthly_active_users"
 
             txn.execute(sql)
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         return self.runInteraction("count_users", _count_users)
diff --git a/synapse/storage/data_stores/main/push_rule.py b/synapse/storage/data_stores/main/push_rule.py
index cd95f1ce60..b520062d84 100644
--- a/synapse/storage/data_stores/main/push_rule.py
+++ b/synapse/storage/data_stores/main/push_rule.py
@@ -143,7 +143,7 @@ class PushRulesWorkerStore(
                     " WHERE user_id = ? AND ? < stream_id"
                 )
                 txn.execute(sql, (user_id, last_id))
-                count, = txn.fetchone()
+                (count,) = txn.fetchone()
                 return bool(count)
 
             return self.runInteraction(
diff --git a/synapse/storage/data_stores/main/registration.py b/synapse/storage/data_stores/main/registration.py
index 6c5b29288a..f70d41ecab 100644
--- a/synapse/storage/data_stores/main/registration.py
+++ b/synapse/storage/data_stores/main/registration.py
@@ -459,7 +459,7 @@ class RegistrationWorkerStore(SQLBaseStore):
                 WHERE appservice_id IS NULL
             """
             )
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         ret = yield self.runInteraction("count_users", _count_users)
diff --git a/synapse/storage/data_stores/main/roommember.py b/synapse/storage/data_stores/main/roommember.py
index bc04bfd7d4..2af24a20b7 100644
--- a/synapse/storage/data_stores/main/roommember.py
+++ b/synapse/storage/data_stores/main/roommember.py
@@ -927,7 +927,7 @@ class RoomMemberBackgroundUpdateStore(BackgroundUpdateStore):
                 if not row or not row[0]:
                     return processed, True
 
-                next_room, = row
+                (next_room,) = row
 
                 sql = """
                     UPDATE current_state_events
diff --git a/synapse/storage/data_stores/main/search.py b/synapse/storage/data_stores/main/search.py
index a59b8331e1..d1d7c6863d 100644
--- a/synapse/storage/data_stores/main/search.py
+++ b/synapse/storage/data_stores/main/search.py
@@ -672,7 +672,7 @@ class SearchStore(SearchBackgroundUpdateStore):
                     )
                 )
                 txn.execute(query, (value, search_query))
-                headline, = txn.fetchall()[0]
+                (headline,) = txn.fetchall()[0]
 
                 # Now we need to pick the possible highlights out of the haedline
                 # result.
diff --git a/synapse/storage/data_stores/main/state.py b/synapse/storage/data_stores/main/state.py
index 9b2207075b..3132848034 100644
--- a/synapse/storage/data_stores/main/state.py
+++ b/synapse/storage/data_stores/main/state.py
@@ -725,16 +725,18 @@ class StateGroupWorkerStore(
         member_filter, non_member_filter = state_filter.get_member_split()
 
         # Now we look them up in the member and non-member caches
-        non_member_state, incomplete_groups_nm, = (
-            yield self._get_state_for_groups_using_cache(
-                groups, self._state_group_cache, state_filter=non_member_filter
-            )
+        (
+            non_member_state,
+            incomplete_groups_nm,
+        ) = yield self._get_state_for_groups_using_cache(
+            groups, self._state_group_cache, state_filter=non_member_filter
         )
 
-        member_state, incomplete_groups_m, = (
-            yield self._get_state_for_groups_using_cache(
-                groups, self._state_group_members_cache, state_filter=member_filter
-            )
+        (
+            member_state,
+            incomplete_groups_m,
+        ) = yield self._get_state_for_groups_using_cache(
+            groups, self._state_group_members_cache, state_filter=member_filter
         )
 
         state = dict(non_member_state)
@@ -1076,7 +1078,7 @@ class StateBackgroundUpdateStore(
                     " WHERE id < ? AND room_id = ?",
                     (state_group, room_id),
                 )
-                prev_group, = txn.fetchone()
+                (prev_group,) = txn.fetchone()
                 new_last_state_group = state_group
 
                 if prev_group:
diff --git a/synapse/storage/data_stores/main/stats.py b/synapse/storage/data_stores/main/stats.py
index 4d59b7833f..45b3de7d56 100644
--- a/synapse/storage/data_stores/main/stats.py
+++ b/synapse/storage/data_stores/main/stats.py
@@ -773,7 +773,7 @@ class StatsStore(StateDeltasStore):
                 (room_id,),
             )
 
-            current_state_events_count, = txn.fetchone()
+            (current_state_events_count,) = txn.fetchone()
 
             users_in_room = self.get_users_in_room_txn(txn, room_id)
 
@@ -863,7 +863,7 @@ class StatsStore(StateDeltasStore):
                 """,
                 (user_id,),
             )
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count, pos
 
         joined_rooms, pos = yield self.runInteraction(
diff --git a/synapse/storage/util/id_generators.py b/synapse/storage/util/id_generators.py
index cbb0a4810a..9d851beaa5 100644
--- a/synapse/storage/util/id_generators.py
+++ b/synapse/storage/util/id_generators.py
@@ -46,7 +46,7 @@ def _load_current_id(db_conn, table, column, step=1):
         cur.execute("SELECT MAX(%s) FROM %s" % (column, table))
     else:
         cur.execute("SELECT MIN(%s) FROM %s" % (column, table))
-    val, = cur.fetchone()
+    (val,) = cur.fetchone()
     cur.close()
     current_id = int(val) if val else step
     return (max if step > 0 else min)(current_id, step)
diff --git a/tox.ini b/tox.ini
index 50b6afe611..afe9bc909b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -114,7 +114,7 @@ skip_install = True
 basepython = python3.6
 deps =
     flake8
-    black==19.3b0  # We pin so that our tests don't start failing on new releases of black.
+    black==19.10b0  # We pin so that our tests don't start failing on new releases of black.
 commands =
     python -m black --check --diff .
     /bin/sh -c "flake8 synapse tests scripts scripts-dev synctl {env:PEP8SUFFIX:}"
@@ -167,6 +167,6 @@ deps =
 env =
     MYPYPATH = stubs/
 extras = all
-commands = mypy --show-traceback --check-untyped-defs --show-error-codes --follow-imports=normal \
+commands = mypy \
             synapse/logging/ \
             synapse/config/