Use StrCollection in additional places. (#16301)

3 files changed, 9 insertions, 10 deletions

diff --git a/synapse/events/__init__.py b/synapse/events/__init__.py
index 35257a3b1b..3c1777b7ec 100644
--- a/synapse/events/__init__.py
+++ b/synapse/events/__init__.py
@@ -25,7 +25,6 @@ from typing import (
     Iterable,
     List,
     Optional,
-    Sequence,
     Tuple,
     Type,
     TypeVar,
@@ -408,7 +407,7 @@ class EventBase(metaclass=abc.ABCMeta):
     def keys(self) -> Iterable[str]:
         return self._dict.keys()
 
-    def prev_event_ids(self) -> Sequence[str]:
+    def prev_event_ids(self) -> List[str]:
         """Returns the list of prev event IDs. The order matches the order
         specified in the event, though there is no meaning to it.
 
@@ -553,7 +552,7 @@ class FrozenEventV2(EventBase):
         self._event_id = "$" + encode_base64(compute_event_reference_hash(self)[1])
         return self._event_id
 
-    def prev_event_ids(self) -> Sequence[str]:
+    def prev_event_ids(self) -> List[str]:
         """Returns the list of prev event IDs. The order matches the order
         specified in the event, though there is no meaning to it.
 
diff --git a/synapse/events/builder.py b/synapse/events/builder.py
index 14ea0e6640..1165c017ba 100644
--- a/synapse/events/builder.py
+++ b/synapse/events/builder.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-from typing import TYPE_CHECKING, Any, Collection, Dict, List, Optional, Tuple, Union
+from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple, Union
 
 import attr
 from signedjson.types import SigningKey
@@ -28,7 +28,7 @@ from synapse.event_auth import auth_types_for_event
 from synapse.events import EventBase, _EventInternalMetadata, make_event_from_dict
 from synapse.state import StateHandler
 from synapse.storage.databases.main import DataStore
-from synapse.types import EventID, JsonDict
+from synapse.types import EventID, JsonDict, StrCollection
 from synapse.types.state import StateFilter
 from synapse.util import Clock
 from synapse.util.stringutils import random_string
@@ -103,7 +103,7 @@ class EventBuilder:
 
     async def build(
         self,
-        prev_event_ids: Collection[str],
+        prev_event_ids: StrCollection,
         auth_event_ids: Optional[List[str]],
         depth: Optional[int] = None,
     ) -> EventBase:
@@ -136,7 +136,7 @@ class EventBuilder:
 
         format_version = self.room_version.event_format
         # The types of auth/prev events changes between event versions.
-        prev_events: Union[Collection[str], List[Tuple[str, Dict[str, str]]]]
+        prev_events: Union[StrCollection, List[Tuple[str, Dict[str, str]]]]
         auth_events: Union[List[str], List[Tuple[str, Dict[str, str]]]]
         if format_version == EventFormatVersions.ROOM_V1_V2:
             auth_events = await self._store.add_event_hashes(auth_event_ids)
diff --git a/synapse/events/validator.py b/synapse/events/validator.py
index 34625dd7a1..5da50cb0d2 100644
--- a/synapse/events/validator.py
+++ b/synapse/events/validator.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import collections.abc
-from typing import Iterable, List, Type, Union, cast
+from typing import List, Type, Union, cast
 
 import jsonschema
 from pydantic import Field, StrictBool, StrictStr
@@ -36,7 +36,7 @@ from synapse.events.utils import (
 from synapse.federation.federation_server import server_matches_acl_event
 from synapse.http.servlet import validate_json_object
 from synapse.rest.models import RequestBodyModel
-from synapse.types import EventID, JsonDict, RoomID, UserID
+from synapse.types import EventID, JsonDict, RoomID, StrCollection, UserID
 
 
 class EventValidator:
@@ -225,7 +225,7 @@ class EventValidator:
 
             self._ensure_state_event(event)
 
-    def _ensure_strings(self, d: JsonDict, keys: Iterable[str]) -> None:
+    def _ensure_strings(self, d: JsonDict, keys: StrCollection) -> None:
         for s in keys:
             if s not in d:
                 raise SynapseError(400, "'%s' not in content" % (s,))