synapse/tests/handlers/test_sliding_sync.py

#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright (C) 2024 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#
import logging
from typing import AbstractSet
from unittest.mock import patch

import attr
from parameterized import parameterized, parameterized_class

from twisted.internet.testing import MemoryReactor

from synapse.api.constants import (
    EventTypes,
    JoinRules,
    Membership,
)
from synapse.api.room_versions import RoomVersions
from synapse.handlers.sliding_sync import (
    MAX_NUMBER_PREVIOUS_STATE_KEYS_TO_REMEMBER,
    RoomsForUserType,
    RoomSyncConfig,
    StateValues,
    _required_state_changes,
    _RequiredStateChangesReturn,
)
from synapse.rest import admin
from synapse.rest.client import knock, login, room
from synapse.server import HomeServer
from synapse.storage.util.id_generators import MultiWriterIdGenerator
from synapse.types import JsonDict, StateMap, StreamToken, UserID, create_requester
from synapse.types.handlers.sliding_sync import (
    PerConnectionState,
    SlidingSyncConfig,
)
from synapse.types.state import StateFilter
from synapse.util.clock import Clock

from tests import unittest
from tests.replication._base import BaseMultiWorkerStreamTestCase
from tests.rest.client.sliding_sync.test_sliding_sync import SlidingSyncBase
from tests.test_utils.event_injection import create_event
from tests.unittest import HomeserverTestCase, TestCase

logger = logging.getLogger(__name__)


class RoomSyncConfigTestCase(TestCase):
    def _assert_room_config_equal(
        self,
        actual: RoomSyncConfig,
        expected: RoomSyncConfig,
        message_prefix: str | None = None,
    ) -> None:
        self.assertEqual(actual.timeline_limit, expected.timeline_limit, message_prefix)

        # `self.assertEqual(...)` works fine to catch differences but the output is
        # almost impossible to read because of the way it truncates the output and the
        # order doesn't actually matter.
        self.assertCountEqual(
            actual.required_state_map, expected.required_state_map, message_prefix
        )
        for event_type, expected_state_keys in expected.required_state_map.items():
            self.assertCountEqual(
                actual.required_state_map[event_type],
                expected_state_keys,
                f"{message_prefix}: Mismatch for {event_type}",
            )

    @parameterized.expand(
        [
            (
                "from_list_config",
                """
                Test that we can convert a `SlidingSyncConfig.SlidingSyncList` to a
                `RoomSyncConfig`.
                """,
                # Input
                SlidingSyncConfig.SlidingSyncList(
                    timeline_limit=10,
                    required_state=[
                        (EventTypes.Name, ""),
                        (EventTypes.Member, "@foo"),
                        (EventTypes.Member, "@bar"),
                        (EventTypes.Member, "@baz"),
                        (EventTypes.CanonicalAlias, ""),
                    ],
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Name: {""},
                        EventTypes.Member: {
                            "@foo",
                            "@bar",
                            "@baz",
                        },
                        EventTypes.CanonicalAlias: {""},
                    },
                ),
            ),
            (
                "from_room_subscription",
                """
                Test that we can convert a `SlidingSyncConfig.RoomSubscription` to a
                `RoomSyncConfig`.
                """,
                # Input
                SlidingSyncConfig.RoomSubscription(
                    timeline_limit=10,
                    required_state=[
                        (EventTypes.Name, ""),
                        (EventTypes.Member, "@foo"),
                        (EventTypes.Member, "@bar"),
                        (EventTypes.Member, "@baz"),
                        (EventTypes.CanonicalAlias, ""),
                    ],
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Name: {""},
                        EventTypes.Member: {
                            "@foo",
                            "@bar",
                            "@baz",
                        },
                        EventTypes.CanonicalAlias: {""},
                    },
                ),
            ),
            (
                "wildcard",
                """
                Test that a wildcard (*) for both the `event_type` and `state_key` will override
                all other values.

                Note: MSC3575 describes different behavior to how we're handling things here but
                since it's not wrong to return more state than requested (`required_state` is
                just the minimum requested), it doesn't matter if we include things that the
                client wanted excluded. This complexity is also under scrutiny, see
                https://github.com/matrix-org/matrix-spec-proposals/pull/3575#discussion_r1185109050

                > One unique exception is when you request all state events via ["*", "*"]. When used,
                > all state events are returned by default, and additional entries FILTER OUT the returned set
                > of state events. These additional entries cannot use '*' themselves.
                > For example, ["*", "*"], ["m.room.member", "@alice:example.com"] will _exclude_ every m.room.member
                > event _except_ for @alice:example.com, and include every other state event.
                > In addition, ["*", "*"], ["m.space.child", "*"] is an error, the m.space.child filter is not
                > required as it would have been returned anyway.
                >
                > -- MSC3575 (https://github.com/matrix-org/matrix-spec-proposals/pull/3575)
                """,
                # Input
                SlidingSyncConfig.SlidingSyncList(
                    timeline_limit=10,
                    required_state=[
                        (EventTypes.Name, ""),
                        (StateValues.WILDCARD, StateValues.WILDCARD),
                        (EventTypes.Member, "@foo"),
                        (EventTypes.CanonicalAlias, ""),
                    ],
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        StateValues.WILDCARD: {StateValues.WILDCARD},
                    },
                ),
            ),
            (
                "wildcard_type",
                """
                Test that a wildcard (*) as a `event_type` will override all other values for the
                same `state_key`.
                """,
                # Input
                SlidingSyncConfig.SlidingSyncList(
                    timeline_limit=10,
                    required_state=[
                        (EventTypes.Name, ""),
                        (StateValues.WILDCARD, ""),
                        (EventTypes.Member, "@foo"),
                        (EventTypes.CanonicalAlias, ""),
                    ],
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        StateValues.WILDCARD: {""},
                        EventTypes.Member: {"@foo"},
                    },
                ),
            ),
            (
                "multiple_wildcard_type",
                """
                Test that multiple wildcard (*) as a `event_type` will override all other values
                for the same `state_key`.
                """,
                # Input
                SlidingSyncConfig.SlidingSyncList(
                    timeline_limit=10,
                    required_state=[
                        (EventTypes.Name, ""),
                        (StateValues.WILDCARD, ""),
                        (EventTypes.Member, "@foo"),
                        (StateValues.WILDCARD, "@foo"),
                        ("org.matrix.personal_count", "@foo"),
                        (EventTypes.Member, "@bar"),
                        (EventTypes.CanonicalAlias, ""),
                    ],
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        StateValues.WILDCARD: {
                            "",
                            "@foo",
                        },
                        EventTypes.Member: {"@bar"},
                    },
                ),
            ),
            (
                "wildcard_state_key",
                """
                Test that a wildcard (*) as a `state_key` will override all other values for the
                same `event_type`.
                """,
                # Input
                SlidingSyncConfig.SlidingSyncList(
                    timeline_limit=10,
                    required_state=[
                        (EventTypes.Name, ""),
                        (EventTypes.Member, "@foo"),
                        (EventTypes.Member, StateValues.WILDCARD),
                        (EventTypes.Member, "@bar"),
                        (EventTypes.Member, StateValues.LAZY),
                        (EventTypes.Member, "@baz"),
                        (EventTypes.CanonicalAlias, ""),
                    ],
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Name: {""},
                        EventTypes.Member: {
                            StateValues.WILDCARD,
                        },
                        EventTypes.CanonicalAlias: {""},
                    },
                ),
            ),
            (
                "wildcard_merge",
                """
                Test that a wildcard (*) entries for the `event_type` and another one for
                `state_key` will play together.
                """,
                # Input
                SlidingSyncConfig.SlidingSyncList(
                    timeline_limit=10,
                    required_state=[
                        (EventTypes.Name, ""),
                        (StateValues.WILDCARD, ""),
                        (EventTypes.Member, "@foo"),
                        (EventTypes.Member, StateValues.WILDCARD),
                        (EventTypes.Member, "@bar"),
                        (EventTypes.CanonicalAlias, ""),
                    ],
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        StateValues.WILDCARD: {""},
                        EventTypes.Member: {StateValues.WILDCARD},
                    },
                ),
            ),
            (
                "wildcard_merge2",
                """
                Test that an all wildcard ("*", "*") entry will override any other
                values (including other wildcards).
                """,
                # Input
                SlidingSyncConfig.SlidingSyncList(
                    timeline_limit=10,
                    required_state=[
                        (EventTypes.Name, ""),
                        (StateValues.WILDCARD, ""),
                        (EventTypes.Member, StateValues.WILDCARD),
                        (EventTypes.Member, "@foo"),
                        # One of these should take precedence over everything else
                        (StateValues.WILDCARD, StateValues.WILDCARD),
                        (StateValues.WILDCARD, StateValues.WILDCARD),
                        (EventTypes.CanonicalAlias, ""),
                    ],
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        StateValues.WILDCARD: {StateValues.WILDCARD},
                    },
                ),
            ),
            (
                "lazy_members",
                """
                `$LAZY` room members should just be another additional key next to other
                explicit keys. We will unroll the special `$LAZY` meaning later.
                """,
                # Input
                SlidingSyncConfig.SlidingSyncList(
                    timeline_limit=10,
                    required_state=[
                        (EventTypes.Name, ""),
                        (EventTypes.Member, "@foo"),
                        (EventTypes.Member, "@bar"),
                        (EventTypes.Member, StateValues.LAZY),
                        (EventTypes.Member, "@baz"),
                        (EventTypes.CanonicalAlias, ""),
                    ],
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Name: {""},
                        EventTypes.Member: {
                            "@foo",
                            "@bar",
                            StateValues.LAZY,
                            "@baz",
                        },
                        EventTypes.CanonicalAlias: {""},
                    },
                ),
            ),
        ]
    )
    def test_from_room_config(
        self,
        _test_label: str,
        _test_description: str,
        room_params: SlidingSyncConfig.CommonRoomParameters,
        expected_room_sync_config: RoomSyncConfig,
    ) -> None:
        """
        Test `RoomSyncConfig.from_room_config(room_params)` will result in the `expected_room_sync_config`.
        """
        room_sync_config = RoomSyncConfig.from_room_config(room_params)

        self._assert_room_config_equal(
            room_sync_config,
            expected_room_sync_config,
        )

    @parameterized.expand(
        [
            (
                "no_direct_overlap",
                # A
                RoomSyncConfig(
                    timeline_limit=9,
                    required_state_map={
                        EventTypes.Name: {""},
                        EventTypes.Member: {
                            "@foo",
                            "@bar",
                        },
                    },
                ),
                # B
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Member: {
                            StateValues.LAZY,
                            "@baz",
                        },
                        EventTypes.CanonicalAlias: {""},
                    },
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Name: {""},
                        EventTypes.Member: {
                            "@foo",
                            "@bar",
                            StateValues.LAZY,
                            "@baz",
                        },
                        EventTypes.CanonicalAlias: {""},
                    },
                ),
            ),
            (
                "wildcard_overlap",
                # A
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        StateValues.WILDCARD: {StateValues.WILDCARD},
                    },
                ),
                # B
                RoomSyncConfig(
                    timeline_limit=9,
                    required_state_map={
                        EventTypes.Dummy: {StateValues.WILDCARD},
                        StateValues.WILDCARD: {"@bar"},
                        EventTypes.Member: {"@foo"},
                    },
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        StateValues.WILDCARD: {StateValues.WILDCARD},
                    },
                ),
            ),
            (
                "state_type_wildcard_overlap",
                # A
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Dummy: {"dummy"},
                        StateValues.WILDCARD: {
                            "",
                            "@foo",
                        },
                        EventTypes.Member: {"@bar"},
                    },
                ),
                # B
                RoomSyncConfig(
                    timeline_limit=9,
                    required_state_map={
                        EventTypes.Dummy: {"dummy2"},
                        StateValues.WILDCARD: {
                            "",
                            "@bar",
                        },
                        EventTypes.Member: {"@foo"},
                    },
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Dummy: {
                            "dummy",
                            "dummy2",
                        },
                        StateValues.WILDCARD: {
                            "",
                            "@foo",
                            "@bar",
                        },
                    },
                ),
            ),
            (
                "state_key_wildcard_overlap",
                # A
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Dummy: {"dummy"},
                        EventTypes.Member: {StateValues.WILDCARD},
                        "org.matrix.flowers": {StateValues.WILDCARD},
                    },
                ),
                # B
                RoomSyncConfig(
                    timeline_limit=9,
                    required_state_map={
                        EventTypes.Dummy: {StateValues.WILDCARD},
                        EventTypes.Member: {StateValues.WILDCARD},
                        "org.matrix.flowers": {"tulips"},
                    },
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Dummy: {StateValues.WILDCARD},
                        EventTypes.Member: {StateValues.WILDCARD},
                        "org.matrix.flowers": {StateValues.WILDCARD},
                    },
                ),
            ),
            (
                "state_type_and_state_key_wildcard_merge",
                # A
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Dummy: {"dummy"},
                        StateValues.WILDCARD: {
                            "",
                            "@foo",
                        },
                        EventTypes.Member: {"@bar"},
                    },
                ),
                # B
                RoomSyncConfig(
                    timeline_limit=9,
                    required_state_map={
                        EventTypes.Dummy: {"dummy2"},
                        StateValues.WILDCARD: {""},
                        EventTypes.Member: {StateValues.WILDCARD},
                    },
                ),
                # Expected
                RoomSyncConfig(
                    timeline_limit=10,
                    required_state_map={
                        EventTypes.Dummy: {
                            "dummy",
                            "dummy2",
                        },
                        StateValues.WILDCARD: {
                            "",
                            "@foo",
                        },
                        EventTypes.Member: {StateValues.WILDCARD},
                    },
                ),
            ),
        ]
    )
    def test_combine_room_sync_config(
        self,
        _test_label: str,
        a: RoomSyncConfig,
        b: RoomSyncConfig,
        expected: RoomSyncConfig,
    ) -> None:
        """
        Combine A into B and B into A to make sure we get the same result.
        """
        combined_config = a.combine_room_sync_config(b)
        self._assert_room_config_equal(combined_config, expected, "B into A")

        combined_config = a.combine_room_sync_config(b)
        self._assert_room_config_equal(combined_config, expected, "A into B")


# FIXME: This can be removed once we bump `SCHEMA_COMPAT_VERSION` and run the
# foreground update for
# `sliding_sync_joined_rooms`/`sliding_sync_membership_snapshots` (tracked by
# https://github.com/element-hq/synapse/issues/17623)
@parameterized_class(
    ("use_new_tables",),
    [
        (True,),
        (False,),
    ],
    class_name_func=lambda cls,
    num,
    params_dict: f"{cls.__name__}_{'new' if params_dict['use_new_tables'] else 'fallback'}",
)
class ComputeInterestedRoomsTestCase(SlidingSyncBase):
    """
    Tests Sliding Sync handler `compute_interested_rooms()` to make sure it returns
    the correct list of rooms IDs.
    """

    # FIXME: We should refactor these tests to run against `compute_interested_rooms(...)`
    # instead of just `get_room_membership_for_user_at_to_token(...)` which is only used
    # in the fallback path (`_compute_interested_rooms_fallback(...)`). These scenarios do
    # well to stress that logic and we shouldn't remove them just because we're removing
    # the fallback path (tracked by https://github.com/element-hq/synapse/issues/17623).

    servlets = [
        admin.register_servlets,
        knock.register_servlets,
        login.register_servlets,
        room.register_servlets,
    ]

    def default_config(self) -> JsonDict:
        config = super().default_config()
        # Enable sliding sync
        config["experimental_features"] = {"msc3575_enabled": True}
        return config

    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
        self.sliding_sync_handler = self.hs.get_sliding_sync_handler()
        self.store = self.hs.get_datastores().main
        self.event_sources = hs.get_event_sources()
        self.storage_controllers = hs.get_storage_controllers()
        persistence = self.hs.get_storage_controllers().persistence
        assert persistence is not None
        self.persistence = persistence

        super().prepare(reactor, clock, hs)

    def test_no_rooms(self) -> None:
        """
        Test when the user has never joined any rooms before
        """
        user1_id = self.register_user("user1", "pass")
        # user1_tok = self.login(user1_id, "pass")

        now_token = self.event_sources.get_current_token()

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=now_token,
                to_token=now_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)

        self.assertIncludes(room_id_results, set(), exact=True)

    def test_get_newly_joined_room(self) -> None:
        """
        Test that rooms that the user has newly_joined show up. newly_joined is when you
        join after the `from_token` and <= `to_token`.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room_token = self.event_sources.get_current_token()

        room_id = self.helper.create_room_as(user2_id, tok=user2_tok)
        join_response = self.helper.join(room_id, user1_id, tok=user1_tok)

        after_room_token = self.event_sources.get_current_token()

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room_token,
                to_token=after_room_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        self.assertIncludes(
            room_id_results,
            {room_id},
            exact=True,
        )
        # It should be pointing to the join event (latest membership event in the
        # from/to range)
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id].event_id,
            join_response["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id].membership,
            Membership.JOIN,
        )
        # We should be considered `newly_joined` because we joined during the token
        # range
        self.assertTrue(room_id in newly_joined)
        self.assertTrue(room_id not in newly_left)

    def test_get_already_joined_room(self) -> None:
        """
        Test that rooms that the user is already joined show up.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        room_id = self.helper.create_room_as(user2_id, tok=user2_tok)
        join_response = self.helper.join(room_id, user1_id, tok=user1_tok)

        after_room_token = self.event_sources.get_current_token()

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room_token,
                to_token=after_room_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        self.assertIncludes(room_id_results, {room_id}, exact=True)
        # It should be pointing to the join event (latest membership event in the
        # from/to range)
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id].event_id,
            join_response["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id].membership,
            Membership.JOIN,
        )
        # We should *NOT* be `newly_joined` because we joined before the token range
        self.assertTrue(room_id not in newly_joined)
        self.assertTrue(room_id not in newly_left)

    def test_get_invited_banned_knocked_room(self) -> None:
        """
        Test that rooms that the user is invited to, banned from, and knocked on show
        up.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room_token = self.event_sources.get_current_token()

        # Setup the invited room (user2 invites user1 to the room)
        invited_room_id = self.helper.create_room_as(user2_id, tok=user2_tok)
        invite_response = self.helper.invite(
            invited_room_id, targ=user1_id, tok=user2_tok
        )

        # Setup the ban room (user2 bans user1 from the room)
        ban_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, is_public=True
        )
        self.helper.join(ban_room_id, user1_id, tok=user1_tok)
        ban_response = self.helper.ban(
            ban_room_id, src=user2_id, targ=user1_id, tok=user2_tok
        )

        # Setup the knock room (user1 knocks on the room)
        knock_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, room_version=RoomVersions.V7.identifier
        )
        self.helper.send_state(
            knock_room_id,
            EventTypes.JoinRules,
            {"join_rule": JoinRules.KNOCK},
            tok=user2_tok,
        )
        # User1 knocks on the room
        knock_channel = self.make_request(
            "POST",
            "/_matrix/client/r0/knock/%s" % (knock_room_id,),
            b"{}",
            user1_tok,
        )
        self.assertEqual(knock_channel.code, 200, knock_channel.result)
        knock_room_membership_state_event = self.get_success(
            self.storage_controllers.state.get_current_state_event(
                knock_room_id, EventTypes.Member, user1_id
            )
        )
        assert knock_room_membership_state_event is not None

        after_room_token = self.event_sources.get_current_token()

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room_token,
                to_token=after_room_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Ensure that the invited, ban, and knock rooms show up
        self.assertIncludes(
            room_id_results,
            {
                invited_room_id,
                ban_room_id,
                knock_room_id,
            },
            exact=True,
        )
        # It should be pointing to the the respective membership event (latest
        # membership event in the from/to range)
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[invited_room_id].event_id,
            invite_response["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[invited_room_id].membership,
            Membership.INVITE,
        )
        self.assertTrue(invited_room_id not in newly_joined)
        self.assertTrue(invited_room_id not in newly_left)

        self.assertEqual(
            interested_rooms.room_membership_for_user_map[ban_room_id].event_id,
            ban_response["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[ban_room_id].membership,
            Membership.BAN,
        )
        self.assertTrue(ban_room_id not in newly_joined)
        self.assertTrue(ban_room_id not in newly_left)

        self.assertEqual(
            interested_rooms.room_membership_for_user_map[knock_room_id].event_id,
            knock_room_membership_state_event.event_id,
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[knock_room_id].membership,
            Membership.KNOCK,
        )
        self.assertTrue(knock_room_id not in newly_joined)
        self.assertTrue(knock_room_id not in newly_left)

    def test_get_kicked_room(self) -> None:
        """
        Test that a room that the user was kicked from still shows up. When the user
        comes back to their client, they should see that they were kicked.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # Setup the kick room (user2 kicks user1 from the room)
        kick_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, is_public=True
        )
        self.helper.join(kick_room_id, user1_id, tok=user1_tok)
        # Kick user1 from the room
        kick_response = self.helper.change_membership(
            room=kick_room_id,
            src=user2_id,
            targ=user1_id,
            tok=user2_tok,
            membership=Membership.LEAVE,
            extra_data={
                "reason": "Bad manners",
            },
        )

        after_kick_token = self.event_sources.get_current_token()

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_kick_token,
                to_token=after_kick_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # The kicked room should show up
        self.assertIncludes(room_id_results, {kick_room_id}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[kick_room_id].event_id,
            kick_response["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[kick_room_id].membership,
            Membership.LEAVE,
        )
        self.assertNotEqual(
            interested_rooms.room_membership_for_user_map[kick_room_id].sender, user1_id
        )
        # We should *NOT* be `newly_joined` because we were not joined at the the time
        # of the `to_token`.
        self.assertTrue(kick_room_id not in newly_joined)
        self.assertTrue(kick_room_id not in newly_left)

    def test_forgotten_rooms(self) -> None:
        """
        Forgotten rooms do not show up even if we forget after the from/to range.

        Ideally, we would be able to track when the `/forget` happens and apply it
        accordingly in the token range but the forgotten flag is only an extra bool in
        the `room_memberships` table.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # Setup a normal room that we leave. This won't show up in the sync response
        # because we left it before our token but is good to check anyway.
        leave_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, is_public=True
        )
        self.helper.join(leave_room_id, user1_id, tok=user1_tok)
        self.helper.leave(leave_room_id, user1_id, tok=user1_tok)

        # Setup the ban room (user2 bans user1 from the room)
        ban_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, is_public=True
        )
        self.helper.join(ban_room_id, user1_id, tok=user1_tok)
        self.helper.ban(ban_room_id, src=user2_id, targ=user1_id, tok=user2_tok)

        # Setup the kick room (user2 kicks user1 from the room)
        kick_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, is_public=True
        )
        self.helper.join(kick_room_id, user1_id, tok=user1_tok)
        # Kick user1 from the room
        self.helper.change_membership(
            room=kick_room_id,
            src=user2_id,
            targ=user1_id,
            tok=user2_tok,
            membership=Membership.LEAVE,
            extra_data={
                "reason": "Bad manners",
            },
        )

        before_room_forgets = self.event_sources.get_current_token()

        # Forget the room after we already have our tokens. This doesn't change
        # the membership event itself but will mark it internally in Synapse
        channel = self.make_request(
            "POST",
            f"/_matrix/client/r0/rooms/{leave_room_id}/forget",
            content={},
            access_token=user1_tok,
        )
        self.assertEqual(channel.code, 200, channel.result)
        channel = self.make_request(
            "POST",
            f"/_matrix/client/r0/rooms/{ban_room_id}/forget",
            content={},
            access_token=user1_tok,
        )
        self.assertEqual(channel.code, 200, channel.result)
        channel = self.make_request(
            "POST",
            f"/_matrix/client/r0/rooms/{kick_room_id}/forget",
            content={},
            access_token=user1_tok,
        )
        self.assertEqual(channel.code, 200, channel.result)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room_forgets,
                to_token=before_room_forgets,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)

        # We shouldn't see the room because it was forgotten
        self.assertIncludes(room_id_results, set(), exact=True)

    def test_newly_left_rooms(self) -> None:
        """
        Test that newly_left are marked properly
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")

        # Leave before we calculate the `from_token`
        room_id1 = self.helper.create_room_as(user1_id, tok=user1_tok)
        _leave_response1 = self.helper.leave(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Leave during the from_token/to_token range (newly_left)
        room_id2 = self.helper.create_room_as(user1_id, tok=user1_tok)
        leave_response2 = self.helper.leave(room_id2, user1_id, tok=user1_tok)

        after_room2_token = self.event_sources.get_current_token()

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room1_token,
                to_token=after_room2_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # `room_id1` should not show up because it was left before the token range.
        # `room_id2` should show up because it is `newly_left` within the token range.
        self.assertIncludes(
            room_id_results,
            {room_id2},
            exact=True,
            message="Corresponding map to disambiguate the opaque room IDs: "
            + str(
                {
                    "room_id1": room_id1,
                    "room_id2": room_id2,
                }
            ),
        )

        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id2].event_id,
            leave_response2["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id2].membership,
            Membership.LEAVE,
        )
        # We should *NOT* be `newly_joined` because we are instead `newly_left`
        self.assertTrue(room_id2 not in newly_joined)
        self.assertTrue(room_id2 in newly_left)

    def test_no_joins_after_to_token(self) -> None:
        """
        Rooms we join after the `to_token` should *not* show up. See condition "1b)"
        comments in the `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room1_token = self.event_sources.get_current_token()

        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok)
        join_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Room join after our `to_token` shouldn't show up
        room_id2 = self.helper.create_room_as(user2_id, tok=user2_tok)
        self.helper.join(room_id2, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            join_response1["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should be `newly_joined` because we joined during the token range
        self.assertTrue(room_id1 in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_join_during_range_and_left_room_after_to_token(self) -> None:
        """
        Room still shows up if we left the room but were joined during the
        from_token/to_token. See condition "1a)" comments in the
        `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room1_token = self.event_sources.get_current_token()

        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok)
        join_response = self.helper.join(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Leave the room after we already have our tokens
        leave_response = self.helper.leave(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # We should still see the room because we were joined during the
        # from_token/to_token time period.
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            join_response["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response": join_response["event_id"],
                    "leave_response": leave_response["event_id"],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should be `newly_joined` because we joined during the token range
        self.assertTrue(room_id1 in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_join_before_range_and_left_room_after_to_token(self) -> None:
        """
        Room still shows up if we left the room but were joined before the `from_token`
        so it should show up. See condition "1a)" comments in the
        `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok)
        join_response = self.helper.join(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Leave the room after we already have our tokens
        leave_response = self.helper.leave(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # We should still see the room because we were joined before the `from_token`
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            join_response["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response": join_response["event_id"],
                    "leave_response": leave_response["event_id"],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should *NOT* be `newly_joined` because we joined before the token range
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_kicked_before_range_and_left_after_to_token(self) -> None:
        """
        Room still shows up if we left the room but were kicked before the `from_token`
        so it should show up. See condition "1a)" comments in the
        `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # Setup the kick room (user2 kicks user1 from the room)
        kick_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, is_public=True
        )
        join_response1 = self.helper.join(kick_room_id, user1_id, tok=user1_tok)
        # Kick user1 from the room
        kick_response = self.helper.change_membership(
            room=kick_room_id,
            src=user2_id,
            targ=user1_id,
            tok=user2_tok,
            membership=Membership.LEAVE,
            extra_data={
                "reason": "Bad manners",
            },
        )

        after_kick_token = self.event_sources.get_current_token()

        # Leave the room after we already have our tokens
        #
        # We have to join before we can leave (leave -> leave isn't a valid transition
        # or at least it doesn't work in Synapse, 403 forbidden)
        join_response2 = self.helper.join(kick_room_id, user1_id, tok=user1_tok)
        leave_response = self.helper.leave(kick_room_id, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_kick_token,
                to_token=after_kick_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # We shouldn't see the room because it was forgotten
        self.assertIncludes(room_id_results, {kick_room_id}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[kick_room_id].event_id,
            kick_response["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response1": join_response1["event_id"],
                    "kick_response": kick_response["event_id"],
                    "join_response2": join_response2["event_id"],
                    "leave_response": leave_response["event_id"],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[kick_room_id].membership,
            Membership.LEAVE,
        )
        self.assertNotEqual(
            interested_rooms.room_membership_for_user_map[kick_room_id].sender, user1_id
        )
        # We should *NOT* be `newly_joined` because we were kicked
        self.assertTrue(kick_room_id not in newly_joined)
        self.assertTrue(kick_room_id not in newly_left)

    def test_newly_left_during_range_and_join_leave_after_to_token(self) -> None:
        """
        Newly left room should show up. But we're also testing that joining and leaving
        after the `to_token` doesn't mess with the results. See condition "2)" and "1a)"
        comments in the `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room1_token = self.event_sources.get_current_token()

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        # Join and leave the room during the from/to range
        join_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)
        leave_response1 = self.helper.leave(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Join and leave the room after we already have our tokens
        join_response2 = self.helper.join(room_id1, user1_id, tok=user1_tok)
        leave_response2 = self.helper.leave(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should still show up because it's newly_left during the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            leave_response1["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response1": join_response1["event_id"],
                    "leave_response1": leave_response1["event_id"],
                    "join_response2": join_response2["event_id"],
                    "leave_response2": leave_response2["event_id"],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.LEAVE,
        )
        # We should *NOT* be `newly_joined` because we are actually `newly_left` during
        # the token range
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 in newly_left)

    def test_newly_left_during_range_and_join_after_to_token(self) -> None:
        """
        Newly left room should show up. But we're also testing that joining after the
        `to_token` doesn't mess with the results. See condition "2)" and "1b)" comments
        in the `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room1_token = self.event_sources.get_current_token()

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        # Join and leave the room during the from/to range
        join_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)
        leave_response1 = self.helper.leave(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Join the room after we already have our tokens
        join_response2 = self.helper.join(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should still show up because it's newly_left during the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            leave_response1["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response1": join_response1["event_id"],
                    "leave_response1": leave_response1["event_id"],
                    "join_response2": join_response2["event_id"],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.LEAVE,
        )
        # We should *NOT* be `newly_joined` because we are actually `newly_left` during
        # the token range
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 in newly_left)

    def test_no_from_token(self) -> None:
        """
        Test that if we don't provide a `from_token`, we get all the rooms that we had
        membership in up to the `to_token`.

        Providing `from_token` only really has the effect that it marks rooms as
        `newly_left` in the response.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        room_id2 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)

        # Join room1
        join_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)

        # Join and leave the room2 before the `to_token`
        self.helper.join(room_id2, user1_id, tok=user1_tok)
        _leave_response2 = self.helper.leave(room_id2, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Join the room2 after we already have our tokens
        self.helper.join(room_id2, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=None,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Only rooms we were joined to before the `to_token` should show up
        self.assertIncludes(room_id_results, {room_id1}, exact=True)

        # Room1
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            join_response1["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should *NOT* be `newly_joined`/`newly_left` because there is no
        # `from_token` to define a "live" range to compare against
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_from_token_ahead_of_to_token(self) -> None:
        """
        Test when the provided `from_token` comes after the `to_token`. We should
        basically expect the same result as having no `from_token`.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        room_id2 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        room_id3 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        room_id4 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)

        # Join room1 before `to_token`
        join_room1_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)

        # Join and leave the room2 before `to_token`
        _join_room2_response1 = self.helper.join(room_id2, user1_id, tok=user1_tok)
        _leave_room2_response1 = self.helper.leave(room_id2, user1_id, tok=user1_tok)

        # Note: These are purposely swapped. The `from_token` should come after
        # the `to_token` in this test
        to_token = self.event_sources.get_current_token()

        # Join room2 after `to_token`
        _join_room2_response2 = self.helper.join(room_id2, user1_id, tok=user1_tok)

        # --------

        # Join room3 after `to_token`
        _join_room3_response1 = self.helper.join(room_id3, user1_id, tok=user1_tok)

        # Join and leave the room4 after `to_token`
        _join_room4_response1 = self.helper.join(room_id4, user1_id, tok=user1_tok)
        _leave_room4_response1 = self.helper.leave(room_id4, user1_id, tok=user1_tok)

        # Note: These are purposely swapped. The `from_token` should come after the
        # `to_token` in this test
        from_token = self.event_sources.get_current_token()

        # Join the room4 after we already have our tokens
        self.helper.join(room_id4, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=from_token,
                to_token=to_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # In the "current" state snapshot, we're joined to all of the rooms but in the
        # from/to token range...
        self.assertIncludes(
            room_id_results,
            {
                # Included because we were joined before both tokens
                room_id1,
                # Excluded because we left before the `from_token` and `to_token`
                # room_id2,
                # Excluded because we joined after the `to_token`
                # room_id3,
                # Excluded because we joined after the `to_token`
                # room_id4,
            },
            exact=True,
            message="Corresponding map to disambiguate the opaque room IDs: "
            + str(
                {
                    "room_id1": room_id1,
                    "room_id2": room_id2,
                    "room_id3": room_id3,
                    "room_id4": room_id4,
                }
            ),
        )

        # Room1
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            join_room1_response1["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should *NOT* be `newly_joined`/`newly_left` because we joined `room1`
        # before either of the tokens
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_leave_before_range_and_join_leave_after_to_token(self) -> None:
        """
        Test old left rooms. But we're also testing that joining and leaving after the
        `to_token` doesn't mess with the results. See condition "1a)" comments in the
        `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        # Join and leave the room before the from/to range
        self.helper.join(room_id1, user1_id, tok=user1_tok)
        self.helper.leave(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Join and leave the room after we already have our tokens
        self.helper.join(room_id1, user1_id, tok=user1_tok)
        self.helper.leave(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)

        self.assertIncludes(room_id_results, set(), exact=True)

    def test_leave_before_range_and_join_after_to_token(self) -> None:
        """
        Test old left room. But we're also testing that joining after the `to_token`
        doesn't mess with the results. See condition "1b)" comments in the
        `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        # Join and leave the room before the from/to range
        self.helper.join(room_id1, user1_id, tok=user1_tok)
        self.helper.leave(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Join the room after we already have our tokens
        self.helper.join(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)

        self.assertIncludes(room_id_results, set(), exact=True)

    def test_join_leave_multiple_times_during_range_and_after_to_token(
        self,
    ) -> None:
        """
        Join and leave multiple times shouldn't affect rooms from showing up. It just
        matters that we had membership in the from/to range. But we're also testing that
        joining and leaving after the `to_token` doesn't mess with the results.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room1_token = self.event_sources.get_current_token()

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        # Join, leave, join back to the room during the from/to range
        join_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)
        leave_response1 = self.helper.leave(room_id1, user1_id, tok=user1_tok)
        join_response2 = self.helper.join(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Leave and Join the room multiple times after we already have our tokens
        leave_response2 = self.helper.leave(room_id1, user1_id, tok=user1_tok)
        join_response3 = self.helper.join(room_id1, user1_id, tok=user1_tok)
        leave_response3 = self.helper.leave(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because it was newly_left and joined during the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            join_response2["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response1": join_response1["event_id"],
                    "leave_response1": leave_response1["event_id"],
                    "join_response2": join_response2["event_id"],
                    "leave_response2": leave_response2["event_id"],
                    "join_response3": join_response3["event_id"],
                    "leave_response3": leave_response3["event_id"],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should be `newly_joined` because we joined during the token range
        self.assertTrue(room_id1 in newly_joined)
        # We should *NOT* be `newly_left` because we joined during the token range and
        # was still joined at the end of the range
        self.assertTrue(room_id1 not in newly_left)

    def test_join_leave_multiple_times_before_range_and_after_to_token(
        self,
    ) -> None:
        """
        Join and leave multiple times before the from/to range shouldn't affect rooms
        from showing up. It just matters that we had membership in the
        from/to range. But we're also testing that joining and leaving after the
        `to_token` doesn't mess with the results.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        # Join, leave, join back to the room before the from/to range
        join_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)
        leave_response1 = self.helper.leave(room_id1, user1_id, tok=user1_tok)
        join_response2 = self.helper.join(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Leave and Join the room multiple times after we already have our tokens
        leave_response2 = self.helper.leave(room_id1, user1_id, tok=user1_tok)
        join_response3 = self.helper.join(room_id1, user1_id, tok=user1_tok)
        leave_response3 = self.helper.leave(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because we were joined before the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            join_response2["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response1": join_response1["event_id"],
                    "leave_response1": leave_response1["event_id"],
                    "join_response2": join_response2["event_id"],
                    "leave_response2": leave_response2["event_id"],
                    "join_response3": join_response3["event_id"],
                    "leave_response3": leave_response3["event_id"],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should *NOT* be `newly_joined` because we joined before the token range
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_invite_before_range_and_join_leave_after_to_token(
        self,
    ) -> None:
        """
        Make it look like we joined after the token range but we were invited before the
        from/to range so the room should still show up. See condition "1a)" comments in
        the `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)

        # Invited to the room before the token
        invite_response = self.helper.invite(
            room_id1, src=user2_id, targ=user1_id, tok=user2_tok
        )

        after_room1_token = self.event_sources.get_current_token()

        # Join and leave the room after we already have our tokens
        join_respsonse = self.helper.join(room_id1, user1_id, tok=user1_tok)
        leave_response = self.helper.leave(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because we were invited before the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            invite_response["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "invite_response": invite_response["event_id"],
                    "join_respsonse": join_respsonse["event_id"],
                    "leave_response": leave_response["event_id"],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.INVITE,
        )
        # We should *NOT* be `newly_joined` because we were only invited before the
        # token range
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_join_and_display_name_changes_in_token_range(
        self,
    ) -> None:
        """
        Test that we point to the correct membership event within the from/to range even
        if there are multiple `join` membership events in a row indicating
        `displayname`/`avatar_url` updates.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room1_token = self.event_sources.get_current_token()

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        join_response = self.helper.join(room_id1, user1_id, tok=user1_tok)
        # Update the displayname during the token range
        displayname_change_during_token_range_response = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname during token range",
            },
            tok=user1_tok,
        )

        after_room1_token = self.event_sources.get_current_token()

        # Update the displayname after the token range
        displayname_change_after_token_range_response = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname after token range",
            },
            tok=user1_tok,
        )

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because we were joined during the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            displayname_change_during_token_range_response["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response": join_response["event_id"],
                    "displayname_change_during_token_range_response": displayname_change_during_token_range_response[
                        "event_id"
                    ],
                    "displayname_change_after_token_range_response": displayname_change_after_token_range_response[
                        "event_id"
                    ],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should be `newly_joined` because we joined during the token range
        self.assertTrue(room_id1 in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_display_name_changes_in_token_range(
        self,
    ) -> None:
        """
        Test that we point to the correct membership event within the from/to range even
        if there is `displayname`/`avatar_url` updates.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        join_response = self.helper.join(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Update the displayname during the token range
        displayname_change_during_token_range_response = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname during token range",
            },
            tok=user1_tok,
        )

        after_change1_token = self.event_sources.get_current_token()

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room1_token,
                to_token=after_change1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because we were joined during the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            displayname_change_during_token_range_response["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response": join_response["event_id"],
                    "displayname_change_during_token_range_response": displayname_change_during_token_range_response[
                        "event_id"
                    ],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should *NOT* be `newly_joined` because we joined before the token range
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_display_name_changes_before_and_after_token_range(
        self,
    ) -> None:
        """
        Test that we point to the correct membership event even though there are no
        membership events in the from/range but there are `displayname`/`avatar_url`
        changes before/after the token range.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        join_response = self.helper.join(room_id1, user1_id, tok=user1_tok)
        # Update the displayname before the token range
        displayname_change_before_token_range_response = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname during token range",
            },
            tok=user1_tok,
        )

        after_room1_token = self.event_sources.get_current_token()

        # Update the displayname after the token range
        displayname_change_after_token_range_response = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname after token range",
            },
            tok=user1_tok,
        )

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because we were joined before the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            displayname_change_before_token_range_response["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response": join_response["event_id"],
                    "displayname_change_before_token_range_response": displayname_change_before_token_range_response[
                        "event_id"
                    ],
                    "displayname_change_after_token_range_response": displayname_change_after_token_range_response[
                        "event_id"
                    ],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should *NOT* be `newly_joined` because we joined before the token range
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_newly_joined_display_name_changes_leave_after_token_range(
        self,
    ) -> None:
        """
        Test that we point to the correct membership event within the from/to range even
        if we are `newly_joined` and there are multiple `join` membership events in a
        row indicating `displayname`/`avatar_url` updates and we leave after the
        `to_token`.

        See condition "1a)" comments in the `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room1_token = self.event_sources.get_current_token()

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        join_response = self.helper.join(room_id1, user1_id, tok=user1_tok)

        # Update the displayname during the token range
        displayname_change_during_token_range_response = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname during token range",
            },
            tok=user1_tok,
        )

        after_room1_token = self.event_sources.get_current_token()

        # Update the displayname after the token range
        displayname_change_after_token_range_response = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname after token range",
            },
            tok=user1_tok,
        )

        # Leave after the token
        self.helper.leave(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because we were joined during the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            displayname_change_during_token_range_response["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response": join_response["event_id"],
                    "displayname_change_during_token_range_response": displayname_change_during_token_range_response[
                        "event_id"
                    ],
                    "displayname_change_after_token_range_response": displayname_change_after_token_range_response[
                        "event_id"
                    ],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should be `newly_joined` because we joined during the token range
        self.assertTrue(room_id1 in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_display_name_changes_leave_after_token_range(
        self,
    ) -> None:
        """
        Test that we point to the correct membership event within the from/to range even
        if there are multiple `join` membership events in a row indicating
        `displayname`/`avatar_url` updates and we leave after the `to_token`.

        See condition "1a)" comments in the `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        _before_room1_token = self.event_sources.get_current_token()

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        join_response = self.helper.join(room_id1, user1_id, tok=user1_tok)

        after_join_token = self.event_sources.get_current_token()

        # Update the displayname during the token range
        displayname_change_during_token_range_response = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname during token range",
            },
            tok=user1_tok,
        )

        after_display_name_change_token = self.event_sources.get_current_token()

        # Update the displayname after the token range
        displayname_change_after_token_range_response = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname after token range",
            },
            tok=user1_tok,
        )

        # Leave after the token
        self.helper.leave(room_id1, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_join_token,
                to_token=after_display_name_change_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because we were joined during the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            displayname_change_during_token_range_response["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response": join_response["event_id"],
                    "displayname_change_during_token_range_response": displayname_change_during_token_range_response[
                        "event_id"
                    ],
                    "displayname_change_after_token_range_response": displayname_change_after_token_range_response[
                        "event_id"
                    ],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We only changed our display name during the token range so we shouldn't be
        # considered `newly_joined` or `newly_left`
        self.assertTrue(room_id1 not in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_display_name_changes_join_after_token_range(
        self,
    ) -> None:
        """
        Test that multiple `join` membership events (after the `to_token`) in a row
        indicating `displayname`/`avatar_url` updates doesn't affect the results (we
        joined after the token range so it shouldn't show up)

        See condition "1b)" comments in the `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room1_token = self.event_sources.get_current_token()

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)

        after_room1_token = self.event_sources.get_current_token()

        self.helper.join(room_id1, user1_id, tok=user1_tok)
        # Update the displayname after the token range
        self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname after token range",
            },
            tok=user1_tok,
        )

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)

        # Room shouldn't show up because we joined after the from/to range
        self.assertIncludes(room_id_results, set(), exact=True)

    def test_newly_joined_with_leave_join_in_token_range(
        self,
    ) -> None:
        """
        Test that even though we're joined before the token range, if we leave and join
        within the token range, it's still counted as `newly_joined`.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        self.helper.join(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Leave and join back during the token range
        self.helper.leave(room_id1, user1_id, tok=user1_tok)
        join_response2 = self.helper.join(room_id1, user1_id, tok=user1_tok)

        after_more_changes_token = self.event_sources.get_current_token()

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=after_room1_token,
                to_token=after_more_changes_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because we were joined during the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            join_response2["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should be considered `newly_joined` because there is some non-join event in
        # between our latest join event.
        self.assertTrue(room_id1 in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_newly_joined_only_joins_during_token_range(
        self,
    ) -> None:
        """
        Test that a join and more joins caused by display name changes, all during the
        token range, still count as `newly_joined`.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room1_token = self.event_sources.get_current_token()

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        # Join, leave, join back to the room before the from/to range
        join_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)
        # Update the displayname during the token range (looks like another join)
        displayname_change_during_token_range_response1 = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname during token range",
            },
            tok=user1_tok,
        )
        # Update the displayname during the token range (looks like another join)
        displayname_change_during_token_range_response2 = self.helper.send_state(
            room_id1,
            event_type=EventTypes.Member,
            state_key=user1_id,
            body={
                "membership": Membership.JOIN,
                "displayname": "displayname during token range",
            },
            tok=user1_tok,
        )

        after_room1_token = self.event_sources.get_current_token()

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room1_token,
                to_token=after_room1_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room should show up because it was newly_left and joined during the from/to range
        self.assertIncludes(room_id_results, {room_id1}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            displayname_change_during_token_range_response2["event_id"],
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response1": join_response1["event_id"],
                    "displayname_change_during_token_range_response1": displayname_change_during_token_range_response1[
                        "event_id"
                    ],
                    "displayname_change_during_token_range_response2": displayname_change_during_token_range_response2[
                        "event_id"
                    ],
                }
            ),
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should be `newly_joined` because we first joined during the token range
        self.assertTrue(room_id1 in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

    def test_multiple_rooms_are_not_confused(
        self,
    ) -> None:
        """
        Test that multiple rooms are not confused as we fixup the list. This test is
        spawning from a real world bug in the code where I was accidentally using
        `event.room_id` in one of the fix-up loops but the `event` being referenced was
        actually from a different loop.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # We create the room with user2 so the room isn't left with no members when we
        # leave and can still re-join.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        room_id2 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)

        # Invited and left the room before the token
        self.helper.invite(room_id1, src=user2_id, targ=user1_id, tok=user2_tok)
        _leave_room1_response = self.helper.leave(room_id1, user1_id, tok=user1_tok)
        # Invited to room2
        invite_room2_response = self.helper.invite(
            room_id2, src=user2_id, targ=user1_id, tok=user2_tok
        )

        before_room3_token = self.event_sources.get_current_token()

        # Invited and left room3 during the from/to range
        room_id3 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        self.helper.invite(room_id3, src=user2_id, targ=user1_id, tok=user2_tok)
        leave_room3_response = self.helper.leave(room_id3, user1_id, tok=user1_tok)

        after_room3_token = self.event_sources.get_current_token()

        # Join and leave the room after we already have our tokens
        self.helper.join(room_id1, user1_id, tok=user1_tok)
        self.helper.leave(room_id1, user1_id, tok=user1_tok)
        # Leave room2
        self.helper.leave(room_id2, user1_id, tok=user1_tok)
        # Leave room3
        self.helper.leave(room_id3, user1_id, tok=user1_tok)

        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_room3_token,
                to_token=after_room3_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        self.assertIncludes(
            room_id_results,
            {
                #  Excluded because we left before the from/to range
                # room_id1,
                # Invited before the from/to range
                room_id2,
                # `newly_left` during the from/to range
                room_id3,
            },
            exact=True,
        )

        # Room2
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id2].event_id,
            invite_room2_response["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id2].membership,
            Membership.INVITE,
        )
        # We should *NOT* be `newly_joined`/`newly_left` because we were invited before
        # the token range
        self.assertTrue(room_id2 not in newly_joined)
        self.assertTrue(room_id2 not in newly_left)

        # Room3
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id3].event_id,
            leave_room3_response["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id3].membership,
            Membership.LEAVE,
        )
        # We should be `newly_left` because we were invited and left during
        # the token range
        self.assertTrue(room_id3 not in newly_joined)
        self.assertTrue(room_id3 in newly_left)

    def test_state_reset(self) -> None:
        """
        Test a state reset scenario where the user gets removed from the room (when
        there is no corresponding leave event)
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # The room where the state reset will happen
        room_id1 = self.helper.create_room_as(
            user2_id,
            is_public=True,
            tok=user2_tok,
        )
        # Create a dummy event for us to point back to for the state reset
        dummy_event_response = self.helper.send(room_id1, "test", tok=user2_tok)
        dummy_event_id = dummy_event_response["event_id"]

        # Join after the dummy event
        join_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)

        # Join another room so we don't hit the short-circuit and return early if they
        # have no room membership
        room_id2 = self.helper.create_room_as(user2_id, tok=user2_tok)
        self.helper.join(room_id2, user1_id, tok=user1_tok)

        before_reset_token = self.event_sources.get_current_token()

        # Trigger a state reset
        join_rule_event, join_rule_context = self.get_success(
            create_event(
                self.hs,
                prev_event_ids=[dummy_event_id],
                type=EventTypes.JoinRules,
                state_key="",
                content={"join_rule": JoinRules.INVITE},
                sender=user2_id,
                room_id=room_id1,
                room_version=self.get_success(self.store.get_room_version_id(room_id1)),
            )
        )
        _, join_rule_event_pos, _ = self.get_success(
            self.persistence.persist_event(join_rule_event, join_rule_context)
        )

        # Ensure that the state reset worked and only user2 is in the room now
        users_in_room = self.get_success(self.store.get_users_in_room(room_id1))
        self.assertIncludes(set(users_in_room), {user2_id}, exact=True)

        after_reset_token = self.event_sources.get_current_token()

        # The function under test
        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_reset_token,
                to_token=after_reset_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        # Room1 should show up because it was `newly_left` via state reset during the from/to range
        self.assertIncludes(room_id_results, {room_id1, room_id2}, exact=True)
        # It should be pointing to no event because we were removed from the room
        # without a corresponding leave event
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            None,
            "Corresponding map to disambiguate the opaque event IDs: "
            + str(
                {
                    "join_response1": join_response1["event_id"],
                }
            ),
        )
        # State reset caused us to leave the room and there is no corresponding leave event
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.LEAVE,
        )
        # We should *NOT* be `newly_joined` because we joined before the token range
        self.assertTrue(room_id1 not in newly_joined)
        # We should be `newly_left` because we were removed via state reset during the from/to range
        self.assertTrue(room_id1 in newly_left)


# FIXME: This can be removed once we bump `SCHEMA_COMPAT_VERSION` and run the
# foreground update for
# `sliding_sync_joined_rooms`/`sliding_sync_membership_snapshots` (tracked by
# https://github.com/element-hq/synapse/issues/17623)
@parameterized_class(
    ("use_new_tables",),
    [
        (True,),
        (False,),
    ],
    class_name_func=lambda cls,
    num,
    params_dict: f"{cls.__name__}_{'new' if params_dict['use_new_tables'] else 'fallback'}",
)
class ComputeInterestedRoomsShardTestCase(
    BaseMultiWorkerStreamTestCase, SlidingSyncBase
):
    """
    Tests Sliding Sync handler `compute_interested_rooms()` to make sure it works with
    sharded event stream_writers enabled
    """

    # FIXME: We should refactor these tests to run against `compute_interested_rooms(...)`
    # instead of just `get_room_membership_for_user_at_to_token(...)` which is only used
    # in the fallback path (`_compute_interested_rooms_fallback(...)`). These scenarios do
    # well to stress that logic and we shouldn't remove them just because we're removing
    # the fallback path (tracked by https://github.com/element-hq/synapse/issues/17623).

    servlets = [
        admin.register_servlets_for_client_rest_resource,
        room.register_servlets,
        login.register_servlets,
    ]

    def default_config(self) -> dict:
        config = super().default_config()
        # Enable sliding sync
        config["experimental_features"] = {"msc3575_enabled": True}

        # Enable shared event stream_writers
        config["stream_writers"] = {"events": ["worker1", "worker2", "worker3"]}
        config["instance_map"] = {
            "main": {"host": "testserv", "port": 8765},
            "worker1": {"host": "testserv", "port": 1001},
            "worker2": {"host": "testserv", "port": 1002},
            "worker3": {"host": "testserv", "port": 1003},
        }
        return config

    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
        self.sliding_sync_handler = self.hs.get_sliding_sync_handler()
        self.store = self.hs.get_datastores().main
        self.event_sources = hs.get_event_sources()

    def _create_room(self, room_id: str, user_id: str, tok: str) -> None:
        """
        Create a room with a specific room_id. We use this so that that we have a
        consistent room_id across test runs that hashes to the same value and will be
        sharded to a known worker in the tests.
        """

        # We control the room ID generation by patching out the
        # `_generate_room_id` method
        with patch(
            "synapse.handlers.room.RoomCreationHandler._generate_room_id"
        ) as mock:
            mock.side_effect = lambda: room_id
            self.helper.create_room_as(user_id, tok=tok)

    def test_sharded_event_persisters(self) -> None:
        """
        This test should catch bugs that would come from flawed stream position
        (`stream_ordering`) comparisons or making `RoomStreamToken`'s naively. To
        compare event positions properly, you need to consider both the `instance_name`
        and `stream_ordering` together.

        The test creates three event persister workers and a room that is sharded to
        each worker. On worker2, we make the event stream position stuck so that it lags
        behind the other workers and we start getting `RoomStreamToken` that have an
        `instance_map` component (i.e. q`m{min_pos}~{writer1}.{pos1}~{writer2}.{pos2}`).

        We then send some events to advance the stream positions of worker1 and worker3
        but worker2 is lagging behind because it's stuck. We are specifically testing
        that `get_room_membership_for_user_at_to_token(from_token=xxx, to_token=xxx)` should work
        correctly in these adverse conditions.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        self.make_worker_hs(
            "synapse.app.generic_worker",
            {"worker_name": "worker1"},
        )

        worker_hs2 = self.make_worker_hs(
            "synapse.app.generic_worker",
            {"worker_name": "worker2"},
        )

        self.make_worker_hs(
            "synapse.app.generic_worker",
            {"worker_name": "worker3"},
        )

        # Specially crafted room IDs that get persisted on different workers.
        #
        # Sharded to worker1
        room_id1 = "!fooo:test"
        # Sharded to worker2
        room_id2 = "!bar:test"
        # Sharded to worker3
        room_id3 = "!quux:test"

        # Create rooms on the different workers.
        self._create_room(room_id1, user2_id, user2_tok)
        self._create_room(room_id2, user2_id, user2_tok)
        self._create_room(room_id3, user2_id, user2_tok)
        join_response1 = self.helper.join(room_id1, user1_id, tok=user1_tok)
        join_response2 = self.helper.join(room_id2, user1_id, tok=user1_tok)
        # Leave room2
        _leave_room2_response = self.helper.leave(room_id2, user1_id, tok=user1_tok)
        join_response3 = self.helper.join(room_id3, user1_id, tok=user1_tok)
        # Leave room3
        self.helper.leave(room_id3, user1_id, tok=user1_tok)

        # Ensure that the events were sharded to different workers.
        pos1 = self.get_success(
            self.store.get_position_for_event(join_response1["event_id"])
        )
        self.assertEqual(pos1.instance_name, "worker1")
        pos2 = self.get_success(
            self.store.get_position_for_event(join_response2["event_id"])
        )
        self.assertEqual(pos2.instance_name, "worker2")
        pos3 = self.get_success(
            self.store.get_position_for_event(join_response3["event_id"])
        )
        self.assertEqual(pos3.instance_name, "worker3")

        before_stuck_activity_token = self.event_sources.get_current_token()

        # We now gut wrench into the events stream `MultiWriterIdGenerator` on worker2 to
        # mimic it getting stuck persisting an event. This ensures that when we send an
        # event on worker1/worker3 we end up in a state where worker2 events stream
        # position lags that on worker1/worker3, resulting in a RoomStreamToken with a
        # non-empty `instance_map` component.
        #
        # Worker2's event stream position will not advance until we call `__aexit__`
        # again.
        worker_store2 = worker_hs2.get_datastores().main
        assert isinstance(worker_store2._stream_id_gen, MultiWriterIdGenerator)
        actx = worker_store2._stream_id_gen.get_next()
        self.get_success(actx.__aenter__())

        # For room_id1/worker1: leave and join the room to advance the stream position
        # and generate membership changes.
        self.helper.leave(room_id1, user1_id, tok=user1_tok)
        join_room1_response = self.helper.join(room_id1, user1_id, tok=user1_tok)
        # For room_id2/worker2: which is currently stuck, join the room.
        join_on_worker2_response = self.helper.join(room_id2, user1_id, tok=user1_tok)
        # For room_id3/worker3: leave and join the room to advance the stream position
        # and generate membership changes.
        self.helper.leave(room_id3, user1_id, tok=user1_tok)
        join_on_worker3_response = self.helper.join(room_id3, user1_id, tok=user1_tok)

        # Get a token while things are stuck after our activity
        stuck_activity_token = self.event_sources.get_current_token()
        # Let's make sure we're working with a token that has an `instance_map`
        self.assertNotEqual(len(stuck_activity_token.room_key.instance_map), 0)

        # Just double check that the join event on worker2 (that is stuck) happened
        # after the position recorded for worker2 in the token but before the max
        # position in the token. This is crucial for the behavior we're trying to test.
        join_on_worker2_pos = self.get_success(
            self.store.get_position_for_event(join_on_worker2_response["event_id"])
        )
        # Ensure the join technially came after our token
        self.assertGreater(
            join_on_worker2_pos.stream,
            stuck_activity_token.room_key.get_stream_pos_for_instance("worker2"),
        )
        # But less than the max stream position of some other worker
        self.assertLess(
            join_on_worker2_pos.stream,
            # max
            stuck_activity_token.room_key.get_max_stream_pos(),
        )

        # Just double check that the join event on worker3 happened after the min stream
        # value in the token but still within the position recorded for worker3. This is
        # crucial for the behavior we're trying to test.
        join_on_worker3_pos = self.get_success(
            self.store.get_position_for_event(join_on_worker3_response["event_id"])
        )
        # Ensure the join came after the min but still encapsulated by the token
        self.assertGreaterEqual(
            join_on_worker3_pos.stream,
            # min
            stuck_activity_token.room_key.stream,
        )
        self.assertLessEqual(
            join_on_worker3_pos.stream,
            stuck_activity_token.room_key.get_stream_pos_for_instance("worker3"),
        )

        # We finish the fake persisting an event we started above and advance worker2's
        # event stream position (unstuck worker2).
        self.get_success(actx.__aexit__(None, None, None))

        # The function under test
        interested_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.compute_interested_rooms(
                SlidingSyncConfig(
                    user=UserID.from_string(user1_id),
                    requester=create_requester(user_id=user1_id),
                    lists={
                        "foo-list": SlidingSyncConfig.SlidingSyncList(
                            ranges=[(0, 99)],
                            required_state=[],
                            timeline_limit=1,
                        )
                    },
                    conn_id=None,
                ),
                PerConnectionState(),
                from_token=before_stuck_activity_token,
                to_token=stuck_activity_token,
            )
        )
        room_id_results = set(interested_rooms.lists["foo-list"].ops[0].room_ids)
        newly_joined = interested_rooms.newly_joined_rooms
        newly_left = interested_rooms.newly_left_rooms

        self.assertIncludes(
            room_id_results,
            {
                room_id1,
                # Excluded because we left before the from/to range and the second join
                # event happened while worker2 was stuck and technically occurs after
                # the `stuck_activity_token`.
                # room_id2,
                room_id3,
            },
            exact=True,
            message="Corresponding map to disambiguate the opaque room IDs: "
            + str(
                {
                    "room_id1": room_id1,
                    "room_id2": room_id2,
                    "room_id3": room_id3,
                }
            ),
        )

        # Room1
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].event_id,
            join_room1_response["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id1].membership,
            Membership.JOIN,
        )
        # We should be `newly_joined` because we joined during the token range
        self.assertTrue(room_id1 in newly_joined)
        self.assertTrue(room_id1 not in newly_left)

        # Room3
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id3].event_id,
            join_on_worker3_response["event_id"],
        )
        self.assertEqual(
            interested_rooms.room_membership_for_user_map[room_id3].membership,
            Membership.JOIN,
        )
        # We should be `newly_joined` because we joined during the token range
        self.assertTrue(room_id3 in newly_joined)
        self.assertTrue(room_id3 not in newly_left)


class FilterRoomsRelevantForSyncTestCase(HomeserverTestCase):
    """
    Tests Sliding Sync handler `filter_rooms_relevant_for_sync()` to make sure it returns
    the correct list of rooms IDs.
    """

    servlets = [
        admin.register_servlets,
        knock.register_servlets,
        login.register_servlets,
        room.register_servlets,
    ]

    def default_config(self) -> JsonDict:
        config = super().default_config()
        # Enable sliding sync
        config["experimental_features"] = {"msc3575_enabled": True}
        return config

    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
        self.sliding_sync_handler = self.hs.get_sliding_sync_handler()
        self.store = self.hs.get_datastores().main
        self.event_sources = hs.get_event_sources()
        self.storage_controllers = hs.get_storage_controllers()
        persistence = self.hs.get_storage_controllers().persistence
        assert persistence is not None
        self.persistence = persistence

    def _get_sync_room_ids_for_user(
        self,
        user: UserID,
        to_token: StreamToken,
        from_token: StreamToken | None,
    ) -> tuple[dict[str, RoomsForUserType], AbstractSet[str], AbstractSet[str]]:
        """
        Get the rooms the user should be syncing with
        """
        room_membership_for_user_map, newly_joined, newly_left = self.get_success(
            self.sliding_sync_handler.room_lists.get_room_membership_for_user_at_to_token(
                user=user,
                from_token=from_token,
                to_token=to_token,
            )
        )
        filtered_sync_room_map = self.get_success(
            self.sliding_sync_handler.room_lists.filter_rooms_relevant_for_sync(
                user=user,
                room_membership_for_user_map=room_membership_for_user_map,
                newly_left_room_ids=newly_left,
            )
        )

        return filtered_sync_room_map, newly_joined, newly_left

    def test_no_rooms(self) -> None:
        """
        Test when the user has never joined any rooms before
        """
        user1_id = self.register_user("user1", "pass")
        # user1_tok = self.login(user1_id, "pass")

        now_token = self.event_sources.get_current_token()

        room_id_results, newly_joined, newly_left = self._get_sync_room_ids_for_user(
            UserID.from_string(user1_id),
            from_token=now_token,
            to_token=now_token,
        )

        self.assertIncludes(room_id_results.keys(), set(), exact=True)

    def test_basic_rooms(self) -> None:
        """
        Test that rooms that the user is joined to, invited to, banned from, and knocked
        on show up.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_room_token = self.event_sources.get_current_token()

        join_room_id = self.helper.create_room_as(user2_id, tok=user2_tok)
        join_response = self.helper.join(join_room_id, user1_id, tok=user1_tok)

        # Setup the invited room (user2 invites user1 to the room)
        invited_room_id = self.helper.create_room_as(user2_id, tok=user2_tok)
        invite_response = self.helper.invite(
            invited_room_id, targ=user1_id, tok=user2_tok
        )

        # Setup the ban room (user2 bans user1 from the room)
        ban_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, is_public=True
        )
        self.helper.join(ban_room_id, user1_id, tok=user1_tok)
        ban_response = self.helper.ban(
            ban_room_id, src=user2_id, targ=user1_id, tok=user2_tok
        )

        # Setup the knock room (user1 knocks on the room)
        knock_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, room_version=RoomVersions.V7.identifier
        )
        self.helper.send_state(
            knock_room_id,
            EventTypes.JoinRules,
            {"join_rule": JoinRules.KNOCK},
            tok=user2_tok,
        )
        # User1 knocks on the room
        knock_channel = self.make_request(
            "POST",
            "/_matrix/client/r0/knock/%s" % (knock_room_id,),
            b"{}",
            user1_tok,
        )
        self.assertEqual(knock_channel.code, 200, knock_channel.result)
        knock_room_membership_state_event = self.get_success(
            self.storage_controllers.state.get_current_state_event(
                knock_room_id, EventTypes.Member, user1_id
            )
        )
        assert knock_room_membership_state_event is not None

        after_room_token = self.event_sources.get_current_token()

        room_id_results, newly_joined, newly_left = self._get_sync_room_ids_for_user(
            UserID.from_string(user1_id),
            from_token=before_room_token,
            to_token=after_room_token,
        )

        # Ensure that the invited, ban, and knock rooms show up
        self.assertIncludes(
            room_id_results.keys(),
            {
                join_room_id,
                invited_room_id,
                ban_room_id,
                knock_room_id,
            },
            exact=True,
        )
        # It should be pointing to the the respective membership event (latest
        # membership event in the from/to range)
        self.assertEqual(
            room_id_results[join_room_id].event_id,
            join_response["event_id"],
        )
        self.assertEqual(room_id_results[join_room_id].membership, Membership.JOIN)
        self.assertTrue(join_room_id in newly_joined)
        self.assertTrue(join_room_id not in newly_left)

        self.assertEqual(
            room_id_results[invited_room_id].event_id,
            invite_response["event_id"],
        )
        self.assertEqual(room_id_results[invited_room_id].membership, Membership.INVITE)
        self.assertTrue(invited_room_id not in newly_joined)
        self.assertTrue(invited_room_id not in newly_left)

        self.assertEqual(
            room_id_results[ban_room_id].event_id,
            ban_response["event_id"],
        )
        self.assertEqual(room_id_results[ban_room_id].membership, Membership.BAN)
        self.assertTrue(ban_room_id not in newly_joined)
        self.assertTrue(ban_room_id not in newly_left)

        self.assertEqual(
            room_id_results[knock_room_id].event_id,
            knock_room_membership_state_event.event_id,
        )
        self.assertEqual(room_id_results[knock_room_id].membership, Membership.KNOCK)
        self.assertTrue(knock_room_id not in newly_joined)
        self.assertTrue(knock_room_id not in newly_left)

    def test_only_newly_left_rooms_show_up(self) -> None:
        """
        Test that `newly_left` rooms still show up in the sync response but rooms that
        were left before the `from_token` don't show up. See condition "2)" comments in
        the `get_room_membership_for_user_at_to_token()` method.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")

        # Leave before we calculate the `from_token`
        room_id1 = self.helper.create_room_as(user1_id, tok=user1_tok)
        self.helper.leave(room_id1, user1_id, tok=user1_tok)

        after_room1_token = self.event_sources.get_current_token()

        # Leave during the from_token/to_token range (newly_left)
        room_id2 = self.helper.create_room_as(user1_id, tok=user1_tok)
        _leave_response2 = self.helper.leave(room_id2, user1_id, tok=user1_tok)

        after_room2_token = self.event_sources.get_current_token()

        room_id_results, newly_joined, newly_left = self._get_sync_room_ids_for_user(
            UserID.from_string(user1_id),
            from_token=after_room1_token,
            to_token=after_room2_token,
        )

        # Only the `newly_left` room should show up
        self.assertIncludes(room_id_results.keys(), {room_id2}, exact=True)
        self.assertEqual(
            room_id_results[room_id2].event_id,
            _leave_response2["event_id"],
        )
        # We should *NOT* be `newly_joined` because we are instead `newly_left`
        self.assertTrue(room_id2 not in newly_joined)
        self.assertTrue(room_id2 in newly_left)

    def test_get_kicked_room(self) -> None:
        """
        Test that a room that the user was kicked from still shows up. When the user
        comes back to their client, they should see that they were kicked.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # Setup the kick room (user2 kicks user1 from the room)
        kick_room_id = self.helper.create_room_as(
            user2_id, tok=user2_tok, is_public=True
        )
        self.helper.join(kick_room_id, user1_id, tok=user1_tok)
        # Kick user1 from the room
        kick_response = self.helper.change_membership(
            room=kick_room_id,
            src=user2_id,
            targ=user1_id,
            tok=user2_tok,
            membership=Membership.LEAVE,
            extra_data={
                "reason": "Bad manners",
            },
        )

        after_kick_token = self.event_sources.get_current_token()

        room_id_results, newly_joined, newly_left = self._get_sync_room_ids_for_user(
            UserID.from_string(user1_id),
            from_token=after_kick_token,
            to_token=after_kick_token,
        )

        # The kicked room should show up
        self.assertIncludes(room_id_results.keys(), {kick_room_id}, exact=True)
        # It should be pointing to the latest membership event in the from/to range
        self.assertEqual(
            room_id_results[kick_room_id].event_id,
            kick_response["event_id"],
        )
        self.assertEqual(room_id_results[kick_room_id].membership, Membership.LEAVE)
        self.assertNotEqual(room_id_results[kick_room_id].sender, user1_id)
        # We should *NOT* be `newly_joined` because we were not joined at the the time
        # of the `to_token`.
        self.assertTrue(kick_room_id not in newly_joined)
        self.assertTrue(kick_room_id not in newly_left)

    def test_state_reset(self) -> None:
        """
        Test a state reset scenario where the user gets removed from the room (when
        there is no corresponding leave event)
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        # The room where the state reset will happen
        room_id1 = self.helper.create_room_as(
            user2_id,
            is_public=True,
            tok=user2_tok,
        )
        # Create a dummy event for us to point back to for the state reset
        dummy_event_response = self.helper.send(room_id1, "test", tok=user2_tok)
        dummy_event_id = dummy_event_response["event_id"]

        # Join after the dummy event
        self.helper.join(room_id1, user1_id, tok=user1_tok)

        # Join another room so we don't hit the short-circuit and return early if they
        # have no room membership
        room_id2 = self.helper.create_room_as(user2_id, tok=user2_tok)
        self.helper.join(room_id2, user1_id, tok=user1_tok)

        before_reset_token = self.event_sources.get_current_token()

        # Trigger a state reset
        join_rule_event, join_rule_context = self.get_success(
            create_event(
                self.hs,
                prev_event_ids=[dummy_event_id],
                type=EventTypes.JoinRules,
                state_key="",
                content={"join_rule": JoinRules.INVITE},
                sender=user2_id,
                room_id=room_id1,
                room_version=self.get_success(self.store.get_room_version_id(room_id1)),
            )
        )
        _, join_rule_event_pos, _ = self.get_success(
            self.persistence.persist_event(join_rule_event, join_rule_context)
        )

        # Ensure that the state reset worked and only user2 is in the room now
        users_in_room = self.get_success(self.store.get_users_in_room(room_id1))
        self.assertIncludes(set(users_in_room), {user2_id}, exact=True)

        after_reset_token = self.event_sources.get_current_token()

        # The function under test
        room_id_results, newly_joined, newly_left = self._get_sync_room_ids_for_user(
            UserID.from_string(user1_id),
            from_token=before_reset_token,
            to_token=after_reset_token,
        )

        # Room1 should show up because it was `newly_left` via state reset during the from/to range
        self.assertIncludes(room_id_results.keys(), {room_id1, room_id2}, exact=True)
        # It should be pointing to no event because we were removed from the room
        # without a corresponding leave event
        self.assertEqual(
            room_id_results[room_id1].event_id,
            None,
        )
        # State reset caused us to leave the room and there is no corresponding leave event
        self.assertEqual(room_id_results[room_id1].membership, Membership.LEAVE)
        # We should *NOT* be `newly_joined` because we joined before the token range
        self.assertTrue(room_id1 not in newly_joined)
        # We should be `newly_left` because we were removed via state reset during the from/to range
        self.assertTrue(room_id1 in newly_left)


class SortRoomsTestCase(HomeserverTestCase):
    """
    Tests Sliding Sync handler `sort_rooms()` to make sure it sorts/orders rooms
    correctly.
    """

    servlets = [
        admin.register_servlets,
        knock.register_servlets,
        login.register_servlets,
        room.register_servlets,
    ]

    def default_config(self) -> JsonDict:
        config = super().default_config()
        # Enable sliding sync
        config["experimental_features"] = {"msc3575_enabled": True}
        return config

    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
        self.sliding_sync_handler = self.hs.get_sliding_sync_handler()
        self.store = self.hs.get_datastores().main
        self.event_sources = hs.get_event_sources()

    def _get_sync_room_ids_for_user(
        self,
        user: UserID,
        to_token: StreamToken,
        from_token: StreamToken | None,
    ) -> tuple[dict[str, RoomsForUserType], AbstractSet[str], AbstractSet[str]]:
        """
        Get the rooms the user should be syncing with
        """
        room_membership_for_user_map, newly_joined, newly_left = self.get_success(
            self.sliding_sync_handler.room_lists.get_room_membership_for_user_at_to_token(
                user=user,
                from_token=from_token,
                to_token=to_token,
            )
        )
        filtered_sync_room_map = self.get_success(
            self.sliding_sync_handler.room_lists.filter_rooms_relevant_for_sync(
                user=user,
                room_membership_for_user_map=room_membership_for_user_map,
                newly_left_room_ids=newly_left,
            )
        )

        return filtered_sync_room_map, newly_joined, newly_left

    def test_sort_activity_basic(self) -> None:
        """
        Rooms with newer activity are sorted first.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")

        room_id1 = self.helper.create_room_as(
            user1_id,
            tok=user1_tok,
        )
        room_id2 = self.helper.create_room_as(
            user1_id,
            tok=user1_tok,
        )

        after_rooms_token = self.event_sources.get_current_token()

        # Get the rooms the user should be syncing with
        sync_room_map, newly_joined, newly_left = self._get_sync_room_ids_for_user(
            UserID.from_string(user1_id),
            from_token=None,
            to_token=after_rooms_token,
        )

        # Sort the rooms (what we're testing)
        sorted_sync_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.sort_rooms(
                sync_room_map=sync_room_map,
                to_token=after_rooms_token,
            )
        )

        self.assertEqual(
            [room_membership.room_id for room_membership in sorted_sync_rooms],
            [room_id2, room_id1],
        )

    @parameterized.expand(
        [
            (Membership.LEAVE,),
            (Membership.INVITE,),
            (Membership.KNOCK,),
            (Membership.BAN,),
        ]
    )
    def test_activity_after_xxx(self, room1_membership: str) -> None:
        """
        When someone has left/been invited/knocked/been banned from a room, they
        shouldn't take anything into account after that membership event.
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")
        user2_id = self.register_user("user2", "pass")
        user2_tok = self.login(user2_id, "pass")

        before_rooms_token = self.event_sources.get_current_token()

        # Create the rooms as user2 so we can have user1 with a clean slate to work from
        # and join in whatever order we need for the tests.
        room_id1 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        # If we're testing knocks, set the room to knock
        if room1_membership == Membership.KNOCK:
            self.helper.send_state(
                room_id1,
                EventTypes.JoinRules,
                {"join_rule": JoinRules.KNOCK},
                tok=user2_tok,
            )
        room_id2 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)
        room_id3 = self.helper.create_room_as(user2_id, tok=user2_tok, is_public=True)

        # Here is the activity with user1 that will determine the sort of the rooms
        # (room2, room1, room3)
        self.helper.join(room_id3, user1_id, tok=user1_tok)
        if room1_membership == Membership.LEAVE:
            self.helper.join(room_id1, user1_id, tok=user1_tok)
            self.helper.leave(room_id1, user1_id, tok=user1_tok)
        elif room1_membership == Membership.INVITE:
            self.helper.invite(room_id1, src=user2_id, targ=user1_id, tok=user2_tok)
        elif room1_membership == Membership.KNOCK:
            self.helper.knock(room_id1, user1_id, tok=user1_tok)
        elif room1_membership == Membership.BAN:
            self.helper.ban(room_id1, src=user2_id, targ=user1_id, tok=user2_tok)
        self.helper.join(room_id2, user1_id, tok=user1_tok)

        # Activity before the token but the user is only been xxx to this room so it
        # shouldn't be taken into account
        self.helper.send(room_id1, "activity in room1", tok=user2_tok)

        after_rooms_token = self.event_sources.get_current_token()

        # Activity after the token. Just make it in a different order than what we
        # expect to make sure we're not taking the activity after the token into
        # account.
        self.helper.send(room_id1, "activity in room1", tok=user2_tok)
        self.helper.send(room_id2, "activity in room2", tok=user2_tok)
        self.helper.send(room_id3, "activity in room3", tok=user2_tok)

        # Get the rooms the user should be syncing with
        sync_room_map, newly_joined, newly_left = self._get_sync_room_ids_for_user(
            UserID.from_string(user1_id),
            from_token=before_rooms_token,
            to_token=after_rooms_token,
        )

        # Sort the rooms (what we're testing)
        sorted_sync_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.sort_rooms(
                sync_room_map=sync_room_map,
                to_token=after_rooms_token,
            )
        )

        self.assertEqual(
            [room_membership.room_id for room_membership in sorted_sync_rooms],
            [room_id2, room_id1, room_id3],
            "Corresponding map to disambiguate the opaque room IDs: "
            + str(
                {
                    "room_id1": room_id1,
                    "room_id2": room_id2,
                    "room_id3": room_id3,
                }
            ),
        )

    def test_default_bump_event_types(self) -> None:
        """
        Test that we only consider the *latest* event in the room when sorting (not
        `bump_event_types`).
        """
        user1_id = self.register_user("user1", "pass")
        user1_tok = self.login(user1_id, "pass")

        room_id1 = self.helper.create_room_as(
            user1_id,
            tok=user1_tok,
        )
        message_response = self.helper.send(room_id1, "message in room1", tok=user1_tok)
        room_id2 = self.helper.create_room_as(
            user1_id,
            tok=user1_tok,
        )
        self.helper.send(room_id2, "message in room2", tok=user1_tok)

        # Send a reaction in room1 which isn't in `DEFAULT_BUMP_EVENT_TYPES` but we only
        # care about sorting by the *latest* event in the room.
        self.helper.send_event(
            room_id1,
            type=EventTypes.Reaction,
            content={
                "m.relates_to": {
                    "event_id": message_response["event_id"],
                    "key": "👍",
                    "rel_type": "m.annotation",
                }
            },
            tok=user1_tok,
        )

        after_rooms_token = self.event_sources.get_current_token()

        # Get the rooms the user should be syncing with
        sync_room_map, newly_joined, newly_left = self._get_sync_room_ids_for_user(
            UserID.from_string(user1_id),
            from_token=None,
            to_token=after_rooms_token,
        )

        # Sort the rooms (what we're testing)
        sorted_sync_rooms = self.get_success(
            self.sliding_sync_handler.room_lists.sort_rooms(
                sync_room_map=sync_room_map,
                to_token=after_rooms_token,
            )
        )

        self.assertEqual(
            [room_membership.room_id for room_membership in sorted_sync_rooms],
            # room1 sorts before room2 because it has the latest event (the reaction).
            # We only care about the *latest* event in the room.
            [room_id1, room_id2],
        )


@attr.s(slots=True, auto_attribs=True, frozen=True)
class RequiredStateChangesTestParameters:
    previous_required_state_map: dict[str, set[str]]
    request_required_state_map: dict[str, set[str]]
    state_deltas: StateMap[str]
    expected_with_state_deltas: _RequiredStateChangesReturn
    expected_without_state_deltas: _RequiredStateChangesReturn

    previously_returned_lazy_user_ids: AbstractSet[str] = frozenset()
    request_lazy_load_user_ids: AbstractSet[str] = frozenset()


class RequiredStateChangesTestCase(unittest.TestCase):
    """Test cases for `_required_state_changes`"""

    @parameterized.expand(
        [
            (
                "simple_no_change",
                """Test no change to required state""",
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type1": {"state_key"}},
                    request_required_state_map={"type1": {"state_key"}},
                    state_deltas={("type1", "state_key"): "$event_id"},
                    # No changes
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        None, StateFilter.none()
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        None, StateFilter.none()
                    ),
                ),
            ),
            (
                "simple_add_type",
                """Test adding a type to the config""",
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type1": {"state_key"}},
                    request_required_state_map={
                        "type1": {"state_key"},
                        "type2": {"state_key"},
                    },
                    state_deltas={("type2", "state_key"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # We've added a type so we should persist the changed required state
                        # config.
                        {"type1": {"state_key"}, "type2": {"state_key"}},
                        # We should see the new type added
                        StateFilter.from_types([("type2", "state_key")]),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"state_key"}, "type2": {"state_key"}},
                        StateFilter.from_types([("type2", "state_key")]),
                    ),
                ),
            ),
            (
                "simple_add_type_from_nothing",
                """Test adding a type to the config when previously requesting nothing""",
                RequiredStateChangesTestParameters(
                    previous_required_state_map={},
                    request_required_state_map={
                        "type1": {"state_key"},
                        "type2": {"state_key"},
                    },
                    state_deltas={("type2", "state_key"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # We've added a type so we should persist the changed required state
                        # config.
                        {"type1": {"state_key"}, "type2": {"state_key"}},
                        # We should see the new types added
                        StateFilter.from_types(
                            [("type1", "state_key"), ("type2", "state_key")]
                        ),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"state_key"}, "type2": {"state_key"}},
                        StateFilter.from_types(
                            [("type1", "state_key"), ("type2", "state_key")]
                        ),
                    ),
                ),
            ),
            (
                "simple_add_state_key",
                """Test adding a state key to the config""",
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type": {"state_key1"}},
                    request_required_state_map={"type": {"state_key1", "state_key2"}},
                    state_deltas={("type", "state_key2"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # We've added a key so we should persist the changed required state
                        # config.
                        {"type": {"state_key1", "state_key2"}},
                        # We should see the new state_keys added
                        StateFilter.from_types([("type", "state_key2")]),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {"type": {"state_key1", "state_key2"}},
                        StateFilter.from_types([("type", "state_key2")]),
                    ),
                ),
            ),
            (
                "simple_retain_previous_state_keys",
                """Test adding a state key to the config and retaining a previously sent state_key""",
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type": {"state_key1"}},
                    request_required_state_map={"type": {"state_key2", "state_key3"}},
                    state_deltas={("type", "state_key2"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # We've added a key so we should persist the changed required state
                        # config.
                        #
                        # Retain `state_key1` from the `previous_required_state_map`
                        {"type": {"state_key1", "state_key2", "state_key3"}},
                        # We should see the new state_keys added
                        StateFilter.from_types(
                            [("type", "state_key2"), ("type", "state_key3")]
                        ),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {"type": {"state_key1", "state_key2", "state_key3"}},
                        StateFilter.from_types(
                            [("type", "state_key2"), ("type", "state_key3")]
                        ),
                    ),
                ),
            ),
            (
                "simple_remove_type",
                """
                Test removing a type from the config when there are a matching state
                delta does cause the persisted required state config to change

                Test removing a type from the config when there are no matching state
                deltas does *not* cause the persisted required state config to change
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        "type1": {"state_key"},
                        "type2": {"state_key"},
                    },
                    request_required_state_map={"type1": {"state_key"}},
                    state_deltas={("type2", "state_key"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Remove `type2` since there's been a change to that state,
                        # (persist the change to required state). That way next time,
                        # they request `type2`, we see that we haven't sent it before
                        # and send the new state. (we should still keep track that we've
                        # sent `type1` before).
                        {"type1": {"state_key"}},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # `type2` is no longer requested but since that state hasn't
                        # changed, nothing should change (we should still keep track
                        # that we've sent `type2` before).
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "simple_remove_type_to_nothing",
                """
                Test removing a type from the config and no longer requesting any state
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        "type1": {"state_key"},
                        "type2": {"state_key"},
                    },
                    request_required_state_map={},
                    state_deltas={("type2", "state_key"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Remove `type2` since there's been a change to that state,
                        # (persist the change to required state). That way next time,
                        # they request `type2`, we see that we haven't sent it before
                        # and send the new state. (we should still keep track that we've
                        # sent `type1` before).
                        {"type1": {"state_key"}},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # `type2` is no longer requested but since that state hasn't
                        # changed, nothing should change (we should still keep track
                        # that we've sent `type2` before).
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "simple_remove_state_key",
                """
                Test removing a state_key from the config
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type": {"state_key1", "state_key2"}},
                    request_required_state_map={"type": {"state_key1"}},
                    state_deltas={("type", "state_key2"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Remove `(type, state_key2)` since there's been a change
                        # to that state (persist the change to required state).
                        # That way next time, they request `(type, state_key2)`, we see
                        # that we haven't sent it before and send the new state. (we
                        # should still keep track that we've sent `(type, state_key1)`
                        # before).
                        {"type": {"state_key1"}},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # `(type, state_key2)` is no longer requested but since that
                        # state hasn't changed, nothing should change (we should still
                        # keep track that we've sent `(type, state_key1)` and `(type,
                        # state_key2)` before).
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "type_wildcards_add",
                """
                Test adding a wildcard type causes the persisted required state config
                to change and we request everything.

                If a event type wildcard has been added or removed we don't try and do
                anything fancy, and instead always update the effective room required
                state config to match the request.
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type1": {"state_key2"}},
                    request_required_state_map={
                        "type1": {"state_key2"},
                        StateValues.WILDCARD: {"state_key"},
                    },
                    state_deltas={
                        ("other_type", "state_key"): "$event_id",
                    },
                    # We've added a wildcard, so we persist the change and request everything
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"state_key2"}, StateValues.WILDCARD: {"state_key"}},
                        StateFilter.all(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"state_key2"}, StateValues.WILDCARD: {"state_key"}},
                        StateFilter.all(),
                    ),
                ),
            ),
            (
                "type_wildcards_remove",
                """
                Test removing a wildcard type causes the persisted required state config
                to change and request nothing.

                If a event type wildcard has been added or removed we don't try and do
                anything fancy, and instead always update the effective room required
                state config to match the request.
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        "type1": {"state_key2"},
                        StateValues.WILDCARD: {"state_key"},
                    },
                    request_required_state_map={"type1": {"state_key2"}},
                    state_deltas={
                        ("other_type", "state_key"): "$event_id",
                    },
                    # We've removed a type wildcard, so we persist the change but don't request anything
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"state_key2"}},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"state_key2"}},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "state_key_wildcards_add",
                """Test adding a wildcard state_key""",
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type1": {"state_key"}},
                    request_required_state_map={
                        "type1": {"state_key"},
                        "type2": {StateValues.WILDCARD},
                    },
                    state_deltas={("type2", "state_key"): "$event_id"},
                    # We've added a wildcard state_key, so we persist the change and
                    # request all of the state for that type
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"state_key"}, "type2": {StateValues.WILDCARD}},
                        StateFilter.from_types([("type2", None)]),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"state_key"}, "type2": {StateValues.WILDCARD}},
                        StateFilter.from_types([("type2", None)]),
                    ),
                ),
            ),
            (
                "state_key_wildcards_remove",
                """Test removing a wildcard state_key""",
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        "type1": {"state_key"},
                        "type2": {StateValues.WILDCARD},
                    },
                    request_required_state_map={"type1": {"state_key"}},
                    state_deltas={("type2", "state_key"): "$event_id"},
                    # We've removed a state_key wildcard, so we persist the change and
                    # request nothing
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"state_key"}},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                    # We've removed a state_key wildcard but there have been no matching
                    # state changes, so no changes needed, just persist the
                    # `request_required_state_map` as-is.
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "state_key_remove_some",
                """
                Test that removing state keys work when only some of the state keys have
                changed
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        "type1": {"state_key1", "state_key2", "state_key3"}
                    },
                    request_required_state_map={"type1": {"state_key1"}},
                    state_deltas={("type1", "state_key3"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # We've removed some state keys from the type, but only state_key3 was
                        # changed so only that one should be removed.
                        {"type1": {"state_key1", "state_key2"}},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # No changes needed, just persist the
                        # `request_required_state_map` as-is
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "state_key_me_add",
                """
                Test adding state keys work when using "$ME"
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={},
                    request_required_state_map={"type1": {StateValues.ME}},
                    state_deltas={("type1", "@user:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # We've added a type so we should persist the changed required state
                        # config.
                        {"type1": {StateValues.ME}},
                        # We should see the new state_keys added
                        StateFilter.from_types([("type1", "@user:test")]),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {StateValues.ME}},
                        StateFilter.from_types([("type1", "@user:test")]),
                    ),
                ),
            ),
            (
                "state_key_me_remove",
                """
                Test removing state keys work when using "$ME"
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type1": {StateValues.ME}},
                    request_required_state_map={},
                    state_deltas={("type1", "@user:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Remove `type1` since there's been a change to that state,
                        # (persist the change to required state). That way next time,
                        # they request `type1`, we see that we haven't sent it before
                        # and send the new state. (if we were tracking that we sent any
                        # other state, we should still keep track that).
                        {},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # `type1` is no longer requested but since that state hasn't
                        # changed, nothing should change (we should still keep track
                        # that we've sent `type1` before).
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "state_key_user_id_add",
                """
                Test adding state keys work when using your own user ID
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={},
                    request_required_state_map={"type1": {"@user:test"}},
                    state_deltas={("type1", "@user:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # We've added a type so we should persist the changed required state
                        # config.
                        {"type1": {"@user:test"}},
                        # We should see the new state_keys added
                        StateFilter.from_types([("type1", "@user:test")]),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {"@user:test"}},
                        StateFilter.from_types([("type1", "@user:test")]),
                    ),
                ),
            ),
            (
                "state_key_me_remove",
                """
                Test removing state keys work when using your own user ID
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type1": {"@user:test"}},
                    request_required_state_map={},
                    state_deltas={("type1", "@user:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Remove `type1` since there's been a change to that state,
                        # (persist the change to required state). That way next time,
                        # they request `type1`, we see that we haven't sent it before
                        # and send the new state. (if we were tracking that we sent any
                        # other state, we should still keep track that).
                        {},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # `type1` is no longer requested but since that state hasn't
                        # changed, nothing should change (we should still keep track
                        # that we've sent `type1` before).
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "state_key_lazy_add",
                """
                Test adding state keys work when using "$LAZY"
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={},
                    request_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    state_deltas={(EventTypes.Member, "@user:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # If a "$LAZY" has been added or removed we always update the
                        # required state to what was requested for simplicity.
                        {EventTypes.Member: {StateValues.LAZY}},
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {EventTypes.Member: {StateValues.LAZY}},
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "state_key_lazy_remove",
                """
                Test removing state keys work when using "$LAZY"
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    request_required_state_map={},
                    state_deltas={(EventTypes.Member, "@user:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # If a "$LAZY" has been added or removed we always update the
                        # required state to what was requested for simplicity.
                        {},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # `EventTypes.Member` is no longer requested but since that
                        # state hasn't changed, nothing should change (we should still
                        # keep track that we've sent `EventTypes.Member` before).
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "state_key_lazy_keep_previous_memberships_and_no_new_memberships",
                """
                This test mimics a request with lazy-loading room members enabled where
                we have previously sent down user2 and user3's membership events and now
                we're sending down another response without any timeline events.
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    request_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    previously_returned_lazy_user_ids={"@user2:test", "@user3:test"},
                    request_lazy_load_user_ids=set(),
                    state_deltas={(EventTypes.Member, "@user2:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # The `request_required_state_map` hasn't changed
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                        # Previous request did not include any explicit members,
                        # so there is no extra users to add to the lazy cache.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        # Remove "@user2:test" since that state has changed and is no
                        # longer being requested anymore. Since something was removed,
                        # we should persist the changed to required state. That way next
                        # time, they request "@user2:test", we see that we haven't sent
                        # it before and send the new state. (we should still keep track
                        # that we've sent specific `EventTypes.Member` before)
                        lazy_members_invalidated={"@user2:test"},
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # The `request_required_state_map` hasn't changed
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                        # Previous request did not include any explicit members,
                        # so there is no extra users to add to the lazy cache.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        # Nothing should change (we should still keep track that
                        # we've sent specific `EventTypes.Member` before).
                        lazy_members_invalidated=frozenset(),
                    ),
                ),
            ),
            (
                "state_key_lazy_keep_previous_memberships_with_new_memberships",
                """
                This test mimics a request with lazy-loading room members enabled where
                we have previously sent down user2 and user3's membership events and now
                we're sending down another response with a new event from user4.
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    request_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    previously_returned_lazy_user_ids={"@user2:test", "@user3:test"},
                    request_lazy_load_user_ids={"@user4:test"},
                    state_deltas={(EventTypes.Member, "@user2:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # The `request_required_state_map` hasn't changed
                        None,
                        # We should see the new state_keys added
                        StateFilter.from_types([(EventTypes.Member, "@user4:test")]),
                        # Previous request did not include any explicit members,
                        # so there is no extra users to add to the lazy cache.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        # Remove "@user2:test" since that state has changed and
                        # is no longer being requested anymore. Since something
                        # was removed, we also should persist the changed to
                        # required state. That way next time, they request
                        # "@user2:test", we see that we haven't sent it before
                        # and send the new state. (we should still keep track
                        # that we've sent specific `EventTypes.Member` before)
                        lazy_members_invalidated={"@user2:test"},
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # The `request_required_state_map` hasn't changed
                        None,
                        # We should see the new state_keys added
                        StateFilter.from_types([(EventTypes.Member, "@user4:test")]),
                        # Previous request did not include any explicit members,
                        # so there is no extra users to add to the lazy cache.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        lazy_members_invalidated=frozenset(),
                    ),
                ),
            ),
            (
                "state_key_expand_lazy_keep_previous_memberships",
                """
                Test expanding the `required_state` to lazy-loading room members.
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        EventTypes.Member: {"@user2:test", "@user3:test"}
                    },
                    request_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    previously_returned_lazy_user_ids=frozenset(),
                    request_lazy_load_user_ids=frozenset(),
                    state_deltas={(EventTypes.Member, "@user2:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Since `StateValues.LAZY` was added, we should persist the
                        # changed required state config.
                        {EventTypes.Member: {StateValues.LAZY}},
                        # No users are being lazy loaded, so nothing to request.
                        StateFilter.none(),
                        # Remember the fact that we've sent @user3 down before,
                        # but not @user2 as that has been invalidated.
                        extra_users_to_add_to_lazy_cache={"@user3:test"},
                        # Nothing to invalidate as there are no existing lazy members.
                        lazy_members_invalidated=frozenset(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # Since `StateValues.LAZY` was added, we should persist the
                        # changed required state config.
                        {EventTypes.Member: {StateValues.LAZY}},
                        # No users are being lazy loaded, so nothing to request.
                        StateFilter.none(),
                        # Remember the fact that we've sent the users down before.
                        extra_users_to_add_to_lazy_cache={"@user2:test", "@user3:test"},
                        # Nothing to invalidate as there are no existing lazy members.
                        lazy_members_invalidated=frozenset(),
                    ),
                ),
            ),
            (
                "state_key_expand_lazy_keep_previous_memberships_need_previous_sent",
                """
                Test expanding the `required_state` to lazy-loading room
                members. If a previously explicit membership is requested then
                we should not send it again (as it was already sent before).
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        EventTypes.Member: {"@user2:test", "@user3:test"}
                    },
                    request_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    previously_returned_lazy_user_ids=frozenset(),
                    request_lazy_load_user_ids={"@user3:test"},
                    state_deltas={(EventTypes.Member, "@user2:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Since `StateValues.LAZY` was added, we should persist the
                        # changed required state config.
                        {EventTypes.Member: {StateValues.LAZY}},
                        # We have already sent @user3 down before.
                        #
                        # `@user3:test` is required for lazy loading, but we've
                        # already sent it down before (due to it being in
                        # `previous_required_state_map`), so we don't need to
                        # request it again.
                        StateFilter.none(),
                        # Remember the fact that we've sent @user3 down before,
                        # but not @user2 as that has been invalidated.
                        extra_users_to_add_to_lazy_cache={"@user3:test"},
                        # Nothing to invalidate as there are no existing lazy members.
                        lazy_members_invalidated=frozenset(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # Since `StateValues.LAZY` was added, we should persist the
                        # changed required state config.
                        {EventTypes.Member: {StateValues.LAZY}},
                        # We have already sent @user3 down before.
                        #
                        # `@user3:test` is required for lazy loading, but we've
                        # already sent it down before (due to it being in
                        # `previous_required_state_map`), so we don't need to
                        # request it again.
                        StateFilter.none(),
                        # Remember the fact that we've sent the users down before.
                        extra_users_to_add_to_lazy_cache={"@user2:test", "@user3:test"},
                        # Nothing to invalidate as there are no existing lazy members.
                        lazy_members_invalidated=frozenset(),
                    ),
                ),
            ),
            (
                "state_key_retract_lazy_keep_previous_memberships_no_new_memberships",
                """
                Test retracting the `required_state` to no longer lazy-loading room members.
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    request_required_state_map={},
                    previously_returned_lazy_user_ids={"@user2:test", "@user3:test"},
                    request_lazy_load_user_ids=set(),
                    state_deltas={(EventTypes.Member, "@user2:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Remove `EventTypes.Member` since there's been a change to that
                        # state, (persist the change to required state).
                        {},
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                        # Previous request did not include any explicit members,
                        # so there is no extra users to add to the lazy cache.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        # Explicitly remove the now invalidated @user2:test
                        # membership.
                        #
                        # We don't invalidate @user3:test as that membership
                        # hasn't changed. We continue to store the existing lazy
                        # members since they might be useful for future
                        # requests. (Alternatively, we could invalidate all
                        # members in the room when the client stops lazy
                        # loading, but we opt to keep track of them).
                        lazy_members_invalidated={"@user2:test"},
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # `EventTypes.Member` is no longer requested but since that
                        # state hasn't changed, nothing should change (we should still
                        # keep track that we've sent `EventTypes.Member` before).
                        None,
                        # We don't need to request anything more if they are requesting
                        # less state now
                        StateFilter.none(),
                        # Previous request did not include any explicit members,
                        # so there is no extra users to add to the lazy cache.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        # Nothing has been invalidated.
                        lazy_members_invalidated=frozenset(),
                    ),
                ),
            ),
            (
                "state_key_retract_lazy_keep_previous_explicit_memberships",
                """
                Test removing explicit memberships from the `required_state`
                when lazy-loading room members tracks previously sent
                memberships.
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        EventTypes.Member: {
                            StateValues.LAZY,
                            "@user2:test",
                            "@user3:test",
                        }
                    },
                    request_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    previously_returned_lazy_user_ids=frozenset(),
                    request_lazy_load_user_ids={"@user3:test"},
                    state_deltas={(EventTypes.Member, "@user2:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Since an explicit membership was removed, we record
                        # the new required state config and move them to lazy
                        # members.
                        {EventTypes.Member: {StateValues.LAZY}},
                        # We have already sent @user3 down before.
                        #
                        # `@user3:test` is required for lazy loading, but we've
                        # already sent it down before (due to it being in
                        # `previous_required_state_map`), so we don't need to
                        # request it again.
                        StateFilter.none(),
                        # Remember the fact that we've sent @user3 down before,
                        # but not @user2 as that has been invalidated.
                        extra_users_to_add_to_lazy_cache={"@user3:test"},
                        # Nothing to invalidate as there are no existing lazy members.
                        lazy_members_invalidated=frozenset(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # While some explicit memberships were removed, there were no
                        # state changes, so we don't need to persist the new required
                        # state config yet.
                        None,
                        # We have already sent @user3 down before.
                        #
                        # `@user3:test` is required for lazy loading, but we've
                        # already sent it down before (due to it being in
                        # `previous_required_state_map`), so we don't need to
                        # request it again.
                        StateFilter.none(),
                        # Remember the fact that we've sent the users down before.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        # Nothing to invalidate as there are no existing lazy members.
                        lazy_members_invalidated=frozenset(),
                    ),
                ),
            ),
            (
                "state_key_retract_lazy_keep_previous_explicit_me_memberships",
                """
                Test removing explicit $ME memberships from the `required_state`
                when lazy-loading room members tracks previously sent
                memberships.
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        EventTypes.Member: {
                            StateValues.LAZY,
                            StateValues.ME,
                            "@user2:test",
                        }
                    },
                    request_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    previously_returned_lazy_user_ids=frozenset(),
                    request_lazy_load_user_ids={"@user:test"},
                    state_deltas={(EventTypes.Member, "@user2:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Since an explicit membership was removed, we record
                        # the new required state config and move them to lazy
                        # members.
                        {EventTypes.Member: {StateValues.LAZY}},
                        # We have already sent @user down before.
                        #
                        # `@user:test` is required for lazy loading, but we've
                        # already sent it down before (due to `StateValues.ME`
                        # being in `previous_required_state_map`), so we don't
                        # need to request it again.
                        StateFilter.none(),
                        # Remember the fact that we've sent @user down before,
                        # but not @user2 as that has been invalidated.
                        extra_users_to_add_to_lazy_cache={"@user:test"},
                        # Nothing to invalidate as there are no existing lazy members.
                        lazy_members_invalidated=frozenset(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # While some explicit memberships were removed, there were no
                        # state changes, so we don't need to persist the new required
                        # state config yet.
                        None,
                        # We have already sent @user down before.
                        #
                        # `@user:test` is required for lazy loading, but we've
                        # already sent it down before (due to `StateValues.ME`
                        # being in `previous_required_state_map`), so we don't
                        # need to request it again.
                        StateFilter.none(),
                        # No relevant state has changed and we don't persist the
                        # changed required_state_map, so we don't yet move the
                        # $ME state to the lazy cache.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        # Nothing to invalidate as there are no existing lazy members.
                        lazy_members_invalidated=frozenset(),
                    ),
                ),
            ),
            (
                "state_key_retract_lazy_keep_previous_memberships_with_new_memberships",
                """
                Test retracting the `required_state` to no longer lazy-loading room members.
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={EventTypes.Member: {StateValues.LAZY}},
                    request_required_state_map={EventTypes.Member: {"@user4:test"}},
                    previously_returned_lazy_user_ids={"@user2:test", "@user3:test"},
                    request_lazy_load_user_ids=frozenset(),
                    state_deltas={(EventTypes.Member, "@user2:test"): "$event_id"},
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        # Since "@user4:test" was added, we should persist the changed
                        # required state config.
                        {EventTypes.Member: {"@user4:test"}},
                        # We should see the new state_keys added
                        StateFilter.from_types([(EventTypes.Member, "@user4:test")]),
                        # Previous request did not include any explicit members,
                        # so there is no extra users to add to the lazy cache.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        # Also remove "@user2:test" since that state has changed and is no
                        # longer being requested anymore. Since something was removed,
                        # we also should persist the changed to required state. That way next
                        # time, they request "@user2:test", we see that we haven't sent
                        # it before and send the new state. (we should still keep track
                        # that we've sent specific `EventTypes.Member` before)
                        lazy_members_invalidated={"@user2:test"},
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        # Since "@user4:test" was added, we should persist the changed
                        # required state config.
                        {EventTypes.Member: {"@user4:test"}},
                        # We should see the new state_keys added
                        StateFilter.from_types([(EventTypes.Member, "@user4:test")]),
                        # Previous request did not include any explicit members,
                        # so there is no extra users to add to the lazy cache.
                        extra_users_to_add_to_lazy_cache=frozenset(),
                        # We don't invalidate user2 as they haven't changed
                        lazy_members_invalidated=frozenset(),
                    ),
                ),
            ),
            (
                "type_wildcard_with_state_key_wildcard_to_explicit_state_keys",
                """
                Test switching from a wildcard ("*", "*") to explicit state keys
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        StateValues.WILDCARD: {StateValues.WILDCARD}
                    },
                    request_required_state_map={
                        StateValues.WILDCARD: {"state_key1", "state_key2", "state_key3"}
                    },
                    state_deltas={("type1", "state_key1"): "$event_id"},
                    # If we were previously fetching everything ("*", "*"), always update the effective
                    # room required state config to match the request. And since we we're previously
                    # already fetching everything, we don't have to fetch anything now that they've
                    # narrowed.
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        {
                            StateValues.WILDCARD: {
                                "state_key1",
                                "state_key2",
                                "state_key3",
                            }
                        },
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {
                            StateValues.WILDCARD: {
                                "state_key1",
                                "state_key2",
                                "state_key3",
                            }
                        },
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "type_wildcard_with_explicit_state_keys_to_wildcard_state_key",
                """
                Test switching from explicit to wildcard state keys ("*", "*")
                """,
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        StateValues.WILDCARD: {"state_key1", "state_key2", "state_key3"}
                    },
                    request_required_state_map={
                        StateValues.WILDCARD: {StateValues.WILDCARD}
                    },
                    state_deltas={("type1", "state_key1"): "$event_id"},
                    # We've added a wildcard, so we persist the change and request everything
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        {StateValues.WILDCARD: {StateValues.WILDCARD}},
                        StateFilter.all(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {StateValues.WILDCARD: {StateValues.WILDCARD}},
                        StateFilter.all(),
                    ),
                ),
            ),
            (
                "state_key_wildcard_to_explicit_state_keys",
                """Test switching from a wildcard to explicit state keys with a concrete type""",
                RequiredStateChangesTestParameters(
                    previous_required_state_map={"type1": {StateValues.WILDCARD}},
                    request_required_state_map={
                        "type1": {"state_key1", "state_key2", "state_key3"}
                    },
                    state_deltas={("type1", "state_key1"): "$event_id"},
                    # If a state_key wildcard has been added or removed, we always
                    # update the effective room required state config to match the
                    # request. And since we we're previously already fetching
                    # everything, we don't have to fetch anything now that they've
                    # narrowed.
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        {
                            "type1": {
                                "state_key1",
                                "state_key2",
                                "state_key3",
                            }
                        },
                        StateFilter.none(),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {
                            "type1": {
                                "state_key1",
                                "state_key2",
                                "state_key3",
                            }
                        },
                        StateFilter.none(),
                    ),
                ),
            ),
            (
                "explicit_state_keys_to_wildcard_state_key",
                """Test switching from a wildcard to explicit state keys with a concrete type""",
                RequiredStateChangesTestParameters(
                    previous_required_state_map={
                        "type1": {"state_key1", "state_key2", "state_key3"}
                    },
                    request_required_state_map={"type1": {StateValues.WILDCARD}},
                    state_deltas={("type1", "state_key1"): "$event_id"},
                    # If a state_key wildcard has been added or removed, we always
                    # update the effective room required state config to match the
                    # request. And we need to request all of the state for that type
                    # because we previously, only sent down a few keys.
                    expected_with_state_deltas=_RequiredStateChangesReturn(
                        {"type1": {StateValues.WILDCARD, "state_key2", "state_key3"}},
                        StateFilter.from_types([("type1", None)]),
                    ),
                    expected_without_state_deltas=_RequiredStateChangesReturn(
                        {
                            "type1": {
                                StateValues.WILDCARD,
                                "state_key1",
                                "state_key2",
                                "state_key3",
                            }
                        },
                        StateFilter.from_types([("type1", None)]),
                    ),
                ),
            ),
        ]
    )
    def test_xxx(
        self,
        _test_label: str,
        _test_description: str,
        test_parameters: RequiredStateChangesTestParameters,
    ) -> None:
        # Without `state_deltas`
        state_changes = _required_state_changes(
            user_id="@user:test",
            prev_required_state_map=test_parameters.previous_required_state_map,
            request_required_state_map=test_parameters.request_required_state_map,
            previously_returned_lazy_user_ids=test_parameters.previously_returned_lazy_user_ids,
            request_lazy_load_user_ids=test_parameters.request_lazy_load_user_ids,
            state_deltas={},
        )

        self.assertEqual(
            state_changes.changed_required_state_map,
            test_parameters.expected_without_state_deltas.changed_required_state_map,
            "changed_required_state_map does not match (without state_deltas)",
        )
        self.assertEqual(
            state_changes.added_state_filter,
            test_parameters.expected_without_state_deltas.added_state_filter,
            "added_state_filter does not match (without state_deltas)",
        )
        self.assertEqual(
            state_changes.lazy_members_invalidated,
            test_parameters.expected_without_state_deltas.lazy_members_invalidated,
            "lazy_members_invalidated does not match (without state_deltas)",
        )
        self.assertEqual(
            state_changes.extra_users_to_add_to_lazy_cache,
            test_parameters.expected_without_state_deltas.extra_users_to_add_to_lazy_cache,
            "lazy_members_previously_returned does not match (without state_deltas)",
        )

        # With `state_deltas`
        state_changes = _required_state_changes(
            user_id="@user:test",
            prev_required_state_map=test_parameters.previous_required_state_map,
            request_required_state_map=test_parameters.request_required_state_map,
            previously_returned_lazy_user_ids=test_parameters.previously_returned_lazy_user_ids,
            request_lazy_load_user_ids=test_parameters.request_lazy_load_user_ids,
            state_deltas=test_parameters.state_deltas,
        )

        self.assertEqual(
            state_changes.changed_required_state_map,
            test_parameters.expected_with_state_deltas.changed_required_state_map,
            "changed_required_state_map does not match (with state_deltas)",
        )
        self.assertEqual(
            state_changes.added_state_filter,
            test_parameters.expected_with_state_deltas.added_state_filter,
            "added_state_filter does not match (with state_deltas)",
        )
        self.assertEqual(
            state_changes.lazy_members_invalidated,
            test_parameters.expected_with_state_deltas.lazy_members_invalidated,
            "lazy_members_invalidated does not match (with state_deltas)",
        )
        self.assertEqual(
            state_changes.extra_users_to_add_to_lazy_cache,
            test_parameters.expected_with_state_deltas.extra_users_to_add_to_lazy_cache,
            "lazy_members_previously_returned does not match (with state_deltas)",
        )

    @parameterized.expand(
        [
            # Test with a normal arbitrary type (no special meaning)
            ("arbitrary_type", "type", set()),
            # Test with membership
            ("membership", EventTypes.Member, set()),
            # Test with lazy-loading room members
            ("lazy_loading_membership", EventTypes.Member, {StateValues.LAZY}),
        ]
    )
    def test_limit_retained_previous_state_keys(
        self,
        _test_label: str,
        event_type: str,
        extra_state_keys: set[str],
    ) -> None:
        """
        Test that we limit the number of state_keys that we remember but always include
        the state_keys that we've just requested.
        """
        previous_required_state_map = {
            event_type: {
                # Prefix the state_keys we've "prev_"iously sent so they are easier to
                # identify in our assertions.
                f"prev_state_key{i}"
                for i in range(MAX_NUMBER_PREVIOUS_STATE_KEYS_TO_REMEMBER - 30)
            }
            | extra_state_keys
        }
        request_required_state_map = {
            event_type: {f"state_key{i}" for i in range(50)} | extra_state_keys
        }

        # (function under test)
        state_changes = _required_state_changes(
            user_id="@user:test",
            prev_required_state_map=previous_required_state_map,
            request_required_state_map=request_required_state_map,
            previously_returned_lazy_user_ids=frozenset(),
            request_lazy_load_user_ids=frozenset(),
            state_deltas={},
        )
        changed_required_state_map = state_changes.changed_required_state_map

        assert changed_required_state_map is not None

        # We should only remember up to the maximum number of state keys
        self.assertGreaterEqual(
            len(changed_required_state_map[event_type]),
            # Most of the time this will be `MAX_NUMBER_PREVIOUS_STATE_KEYS_TO_REMEMBER` but
            # because we are just naively selecting enough previous state_keys to fill
            # the limit, there might be some overlap in what's added back which means we
            # might have slightly less than the limit.
            #
            # `extra_state_keys` overlaps in the previous and requested
            # `required_state_map` so we might see this this scenario.
            MAX_NUMBER_PREVIOUS_STATE_KEYS_TO_REMEMBER - len(extra_state_keys),
        )

        # Should include all of the requested state
        self.assertIncludes(
            changed_required_state_map[event_type],
            request_required_state_map[event_type],
        )
        # And the rest is filled with the previous state keys
        #
        # We can't assert the exact state_keys since we don't know the order so we just
        # check that they all start with "prev_" and that we have the correct amount.
        remaining_state_keys = (
            changed_required_state_map[event_type]
            - request_required_state_map[event_type]
        )
        self.assertGreater(
            len(remaining_state_keys),
            0,
        )
        assert all(
            state_key.startswith("prev_") for state_key in remaining_state_keys
        ), "Remaining state_keys should be the previous state_keys"

    def test_request_more_state_keys_than_remember_limit(self) -> None:
        """
        Test requesting more state_keys than fit in our limit to remember from previous
        requests.
        """
        previous_required_state_map = {
            "type": {
                # Prefix the state_keys we've "prev_"iously sent so they are easier to
                # identify in our assertions.
                f"prev_state_key{i}"
                for i in range(MAX_NUMBER_PREVIOUS_STATE_KEYS_TO_REMEMBER - 30)
            }
        }
        request_required_state_map = {
            "type": {
                f"state_key{i}"
                # Requesting more than the MAX_NUMBER_PREVIOUS_STATE_KEYS_TO_REMEMBER
                for i in range(MAX_NUMBER_PREVIOUS_STATE_KEYS_TO_REMEMBER + 20)
            }
        }
        # Ensure that we are requesting more than the limit
        self.assertGreater(
            len(request_required_state_map["type"]),
            MAX_NUMBER_PREVIOUS_STATE_KEYS_TO_REMEMBER,
        )

        # (function under test)
        state_changes = _required_state_changes(
            user_id="@user:test",
            prev_required_state_map=previous_required_state_map,
            request_required_state_map=request_required_state_map,
            previously_returned_lazy_user_ids=frozenset(),
            request_lazy_load_user_ids=frozenset(),
            state_deltas={},
        )
        changed_required_state_map = state_changes.changed_required_state_map

        assert changed_required_state_map is not None

        # Should include all of the requested state
        self.assertIncludes(
            changed_required_state_map["type"],
            request_required_state_map["type"],
            exact=True,
        )