django-stubs 4.2.1 gives transaction.on_commit a more accurate type
annotation, but this exposed that mypy can’t handle the lambda default
parameters that we use to recapture loop variables such as
for stream_id in public_stream_ids:
peer_user_ids = …
event = …
transaction.on_commit(
lambda event=event, peer_user_ids=peer_user_ids: send_event(
realm, event, peer_user_ids
)
)
https://github.com/python/mypy/issues/15459
A workaround that mypy accepts is
transaction.on_commit(
(
lambda event, peer_user_ids: lambda: send_event(
realm, event, peer_user_ids
)
)(event, peer_user_ids)
)
But that’s kind of ugly and potentially error-prone, so let’s make a
helper function for this very common pattern.
send_event_on_commit(realm, event, peer_user_ids)
Signed-off-by: Anders Kaseorg <anders@zulip.com>
To explain the rationale of this change, for example, there is
`get_user_activity_summary` which accepts either a `Collection[UserActivity]`,
where `QuerySet[T]` is not strictly `Sequence[T]` because its slicing behavior
is different from the `Protocol`, making `Collection` necessary.
Similarily, we should have `Iterable[T]` instead of `List[T]` so that
`QuerySet[T]` will also be an acceptable subtype, or `Sequence[T]` when we
also expect it to be indexed.
Signed-off-by: Zixuan James Li <p359101898@gmail.com>