Message: Add unreact() method

[AnayGarodia]

Summary

• add Message.unreact(emoji) to locate the client's matching reaction event and redact it
• leave the call as a no-op when the client has no matching reaction
• translate relation and redaction failures into MatrixError with the requested message
• cover successful removal, another user's reaction, and Matrix API errors

Verification

• black --fast --check matrix/ tests/
• mypy matrix/
• pytest tests/test_message.py -q (32 passed)
• pytest -q (354 passed)

Closes #114

[Copilot]

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[PenguinBoi12]

Generally it's pretty good, well done. There's only one maintainability issue and a missing test I'd like you to address before I approve this PR. Don't hesitate if you have any questions.

[PenguinBoi12]

I'm not a big fan of duplicating the logic here that we already have in fetch_reactions. However, we can't use fetch_reactions directly because it doesn't contain the information we need (event_id). There's a couple of solutions but I believe the simplest solution for now is extracting the iteration over reactions in a private helper method:

# types.py
@dataclass
class ReactionEvent:
    emoji: str
    sender: str
    event_id: str



# message.py (message class)
async def _iter_reaction_events(self) -> AsyncIterator[ReactionEvent]:
    """Yield (emoji, sender, event_id) for each reaction relation on this message."""
    try:
        async for event in self.client.room_get_event_relations(
            room_id=self.room.room_id,
            event_id=self.event_id,
        ):
            emoji = getattr(event, "key", None)
            sender = getattr(event, "sender", None)
            event_id = getattr(event, "event_id", None)

            if emoji and sender and event_id:
                yield ReactionEvent(emoji=emoji, sender=sender, event_id=event_id)
    except Exception as e:
        raise MatrixError(f"Failed to fetch reactions: {e}")

And then you can use it in both fetch_reactions and unreact:

# message.py (message class)
async def fetch_reactions(self) -> list[Reaction]:
    """..."""
    raw: dict[str, list[str]] = {}

    async for reaction_event in self._iter_reaction_events():
        raw.setdefault(reaction_event.emoji, []).append(reaction_event.sender)

    return [Reaction(key=emoji, senders=senders) for emoji, senders in raw.items()]

...

async def unreact(self, emoji: str) -> None:
    """..."""
    reaction_event_id = None

    async for reaction_event in self._iter_reaction_events():
        if reaction_event.emoji == emoji and reaction_event.sender == self.client.user_id:
            reaction_event_id = reaction_event.event_id
            break

    if reaction_event_id is None:
        return

    await matrix_call(
        self.client.room_redact(
            room_id=self.room.room_id,
            event_id=reaction_event_id,
        ),
        error_message="Failed to remove reaction",
    )

Ideally, we would bring changes to the existing Reaction dataclass so that instead of having sender we have list of ReactionEvent but it might be too out of scope of this PR so it's not required. The changes above are enough for now.

[PenguinBoi12]

Although this will go away with the changes from the comment above, the exception message is identical to the next matrix_call's message which could lead to confusing

[PenguinBoi12]

Good test coverage overall, but there's a small gap: unreact wraps the relation loop, but none of the three tests actually test the possible exception raising from there.

Something like:

@pytest.mark.asyncio
async def test_unreact_with_relations_error__expect_matrix_error(message, client):
    async def mock_relations(*args, **kwargs):
        raise Exception("Network error")
        yield

    client.room_get_event_relations = mock_relations

    with pytest.raises(MatrixError, match="Failed to fetch reactions: ..."):
        await message.unreact("👍")

This is similar to test_fetch_reactions_with_error__expect_matrix_error

[AnayGarodia]

Addressed all requested changes in a2f9b50:

• added a private async reaction-event iterator and reused it from both fetch_reactions() and unreact()
• added the ReactionEvent dataclass with emoji, sender, and event ID
• added coverage for relation-fetch failures in unreact()
• fixed the EOF hook finding in examples/config.yaml

Full pre-commit run --all-files passes, including Black, mypy, and pytest. Ready for re-review.

[PenguinBoi12]

It seems like editor changed some whitespace or something, but it doesn't seem to change anything. Just be careful with that in the future.

[PenguinBoi12]

LGTM 🦭

Thanks for the contribution and don't forget to ⭐