zulip/zerver/tests/test_soft_deactivation.py

from typing import AbstractSet
from unittest import mock

from django.utils.timezone import now as timezone_now

from zerver.actions.alert_words import do_add_alert_words
from zerver.lib.soft_deactivation import (
    add_missing_messages,
    do_auto_soft_deactivate_users,
    do_catch_up_soft_deactivated_users,
    do_soft_activate_users,
    do_soft_deactivate_user,
    do_soft_deactivate_users,
    get_soft_deactivated_users_for_catch_up,
    get_users_for_soft_deactivation,
    reactivate_user_if_soft_deactivated,
)
from zerver.lib.stream_subscription import get_subscriptions_for_send_message
from zerver.lib.test_classes import ZulipTestCase
from zerver.lib.test_helpers import get_subscription, get_user_messages, make_client
from zerver.models import (
    AlertWord,
    Client,
    Message,
    RealmAuditLog,
    Stream,
    UserActivity,
    UserMessage,
    UserProfile,
    get_realm,
    get_stream,
)

logger_string = "zulip.soft_deactivation"


class UserSoftDeactivationTests(ZulipTestCase):
    def test_do_soft_deactivate_user(self) -> None:
        user = self.example_user("hamlet")
        self.assertFalse(user.long_term_idle)

        with self.assertLogs(logger_string, level="INFO") as m:
            do_soft_deactivate_user(user)
        self.assertEqual(m.output, [f"INFO:{logger_string}:Soft deactivated user {user.id}"])

        user.refresh_from_db()
        self.assertTrue(user.long_term_idle)

    def test_do_soft_deactivate_users(self) -> None:
        users = [
            self.example_user("hamlet"),
            self.example_user("iago"),
            self.example_user("cordelia"),
        ]
        for user in users:
            self.assertFalse(user.long_term_idle)

        # We are sending this message to ensure that users have at least
        # one UserMessage row.
        self.send_huddle_message(users[0], users)

        with self.assertLogs(logger_string, level="INFO") as m:
            do_soft_deactivate_users(users)

        log_output = []
        for user in users:
            log_output.append(f"INFO:{logger_string}:Soft deactivated user {user.id}")
        log_output.append(
            f"INFO:{logger_string}:Soft-deactivated batch of {len(users[:100])} users; {len(users[100:])} remain to process"
        )

        self.assertEqual(m.output, log_output)

        for user in users:
            user.refresh_from_db()
            self.assertTrue(user.long_term_idle)

    def test_get_users_for_soft_deactivation(self) -> None:
        users = [
            self.example_user("hamlet"),
            self.example_user("iago"),
            self.example_user("cordelia"),
            self.example_user("ZOE"),
            self.example_user("othello"),
            self.example_user("prospero"),
            self.example_user("aaron"),
            self.example_user("polonius"),
            self.example_user("desdemona"),
            self.example_user("shiva"),
        ]
        client, _ = Client.objects.get_or_create(name="website")
        query = "/some/random/endpoint"
        last_visit = timezone_now()
        count = 150
        for user_profile in UserProfile.objects.all():
            UserActivity.objects.get_or_create(
                user_profile=user_profile,
                client=client,
                query=query,
                count=count,
                last_visit=last_visit,
            )
        filter_kwargs = dict(user_profile__realm=get_realm("zulip"))
        users_to_deactivate = get_users_for_soft_deactivation(-1, filter_kwargs)

        self.assert_length(users_to_deactivate, 10)
        for user in users_to_deactivate:
            self.assertTrue(user in users)

    def test_do_soft_activate_users(self) -> None:
        users = [
            self.example_user("hamlet"),
            self.example_user("iago"),
            self.example_user("cordelia"),
        ]
        self.send_huddle_message(users[0], users)

        with self.assertLogs(logger_string, level="INFO") as m:
            do_soft_deactivate_users(users)

        log_output = []
        for user in users:
            log_output.append(f"INFO:{logger_string}:Soft deactivated user {user.id}")
        log_output.append(
            f"INFO:{logger_string}:Soft-deactivated batch of {len(users[:100])} users; {len(users[100:])} remain to process"
        )

        self.assertEqual(m.output, log_output)

        for user in users:
            self.assertTrue(user.long_term_idle)

        with self.assertLogs(logger_string, level="INFO") as m:
            do_soft_activate_users(users)

        log_output = []
        for user in users:
            log_output.append(f"INFO:{logger_string}:Soft reactivated user {user.id}")

        self.assertEqual(m.output, log_output)

        for user in users:
            user.refresh_from_db()
            self.assertFalse(user.long_term_idle)

    def test_get_users_for_catch_up(self) -> None:
        users = [
            self.example_user("hamlet"),
            self.example_user("iago"),
            self.example_user("cordelia"),
            self.example_user("ZOE"),
            self.example_user("othello"),
            self.example_user("prospero"),
            self.example_user("aaron"),
            self.example_user("polonius"),
            self.example_user("desdemona"),
            self.example_user("shiva"),
        ]
        for user_profile in UserProfile.objects.all():
            user_profile.long_term_idle = True
            user_profile.save(update_fields=["long_term_idle"])

        filter_kwargs = dict(realm=get_realm("zulip"))
        users_to_catch_up = get_soft_deactivated_users_for_catch_up(filter_kwargs)

        self.assert_length(users_to_catch_up, 10)
        for user in users_to_catch_up:
            self.assertTrue(user in users)

    def test_do_catch_up_users(self) -> None:
        stream = "Verona"
        hamlet = self.example_user("hamlet")
        users = [
            self.example_user("iago"),
            self.example_user("cordelia"),
        ]
        all_users = [*users, hamlet]
        for user in all_users:
            self.subscribe(user, stream)

        with self.assertLogs(logger_string, level="INFO") as m:
            do_soft_deactivate_users(users)

        log_output = []
        for user in users:
            log_output.append(f"INFO:{logger_string}:Soft deactivated user {user.id}")
        log_output.append(
            f"INFO:{logger_string}:Soft-deactivated batch of {len(users[:100])} users; {len(users[100:])} remain to process"
        )

        self.assertEqual(m.output, log_output)

        for user in users:
            self.assertTrue(user.long_term_idle)

        message_id = self.send_stream_message(hamlet, stream, "Hello world!")
        already_received = UserMessage.objects.filter(message_id=message_id).count()

        with self.assertLogs(logger_string, level="INFO") as m:
            do_catch_up_soft_deactivated_users(users)
        self.assertEqual(
            m.output, [f"INFO:{logger_string}:Caught up {len(users)} soft-deactivated users"]
        )

        catch_up_received = UserMessage.objects.filter(message_id=message_id).count()
        self.assertEqual(already_received + len(users), catch_up_received)

        for user in users:
            user.refresh_from_db()
            self.assertTrue(user.long_term_idle)
            self.assertEqual(user.last_active_message_id, message_id)

    def test_do_auto_soft_deactivate_users(self) -> None:
        users = [
            self.example_user("iago"),
            self.example_user("cordelia"),
            self.example_user("ZOE"),
            self.example_user("othello"),
            self.example_user("prospero"),
            self.example_user("aaron"),
            self.example_user("polonius"),
            self.example_user("desdemona"),
        ]
        sender = self.example_user("hamlet")
        realm = get_realm("zulip")
        stream_name = "announce"
        for user in [*users, sender]:
            self.subscribe(user, stream_name)

        client, _ = Client.objects.get_or_create(name="website")
        query = "/some/random/endpoint"
        last_visit = timezone_now()
        count = 150
        for user_profile in users:
            UserActivity.objects.get_or_create(
                user_profile=user_profile,
                client=client,
                query=query,
                count=count,
                last_visit=last_visit,
            )

        with self.assertLogs(logger_string, level="INFO") as m:
            users_deactivated = do_auto_soft_deactivate_users(-1, realm)

        log_output = []
        for user in users:
            log_output.append(f"INFO:{logger_string}:Soft deactivated user {user.id}")
        log_output.append(
            f"INFO:{logger_string}:Soft-deactivated batch of {len(users[:100])} users; {len(users[100:])} remain to process"
        )
        log_output.append(f"INFO:{logger_string}:Caught up {len(users)} soft-deactivated users")
        self.assertEqual(set(m.output), set(log_output))

        self.assert_length(users_deactivated, len(users))
        for user in users:
            self.assertTrue(user in users_deactivated)

        # Verify that deactivated users are caught up automatically

        message_id = self.send_stream_message(sender, stream_name)
        received_count = UserMessage.objects.filter(
            user_profile__in=users, message_id=message_id
        ).count()
        self.assertEqual(0, received_count)

        with self.assertLogs(logger_string, level="INFO") as m:
            users_deactivated = do_auto_soft_deactivate_users(-1, realm)

        log_output = []
        log_output.append(f"INFO:{logger_string}:Caught up {len(users)} soft-deactivated users")
        self.assertEqual(set(m.output), set(log_output))

        self.assert_length(users_deactivated, 0)  # all users are already deactivated
        received_count = UserMessage.objects.filter(
            user_profile__in=users, message_id=message_id
        ).count()
        self.assert_length(users, received_count)

        # Verify that deactivated users are NOT caught up if
        # AUTO_CATCH_UP_SOFT_DEACTIVATED_USERS is off

        message_id = self.send_stream_message(sender, stream_name)
        received_count = UserMessage.objects.filter(
            user_profile__in=users, message_id=message_id
        ).count()
        self.assertEqual(0, received_count)

        with self.settings(AUTO_CATCH_UP_SOFT_DEACTIVATED_USERS=False):
            with self.assertLogs(logger_string, level="INFO") as m:
                users_deactivated = do_auto_soft_deactivate_users(-1, realm)
        self.assertEqual(
            m.output,
            [
                f"INFO:{logger_string}:Not catching up users since AUTO_CATCH_UP_SOFT_DEACTIVATED_USERS is off"
            ],
        )

        self.assert_length(users_deactivated, 0)  # all users are already deactivated
        received_count = UserMessage.objects.filter(
            user_profile__in=users, message_id=message_id
        ).count()
        self.assertEqual(0, received_count)


class SoftDeactivationMessageTest(ZulipTestCase):
    def test_reactivate_user_if_soft_deactivated(self) -> None:
        recipient_list = [self.example_user("hamlet"), self.example_user("iago")]
        for user_profile in recipient_list:
            self.subscribe(user_profile, "Denmark")

        sender = self.example_user("iago")
        stream_name = "Denmark"
        topic_name = "foo"

        def last_realm_audit_log_entry(event_type: int) -> RealmAuditLog:
            return RealmAuditLog.objects.filter(event_type=event_type).order_by("-event_time")[0]

        long_term_idle_user = self.example_user("hamlet")
        # We are sending this message to ensure that long_term_idle_user has
        # at least one UserMessage row.
        self.send_stream_message(long_term_idle_user, stream_name)
        with self.assertLogs(logger_string, level="INFO") as info_logs:
            do_soft_deactivate_users([long_term_idle_user])
        self.assertEqual(
            info_logs.output,
            [
                f"INFO:{logger_string}:Soft deactivated user {long_term_idle_user.id}",
                f"INFO:{logger_string}:Soft-deactivated batch of 1 users; 0 remain to process",
            ],
        )

        message = "Test message 1"
        message_id = self.send_stream_message(sender, stream_name, message, topic_name)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        idle_user_msg_count = len(idle_user_msg_list)
        self.assertNotEqual(idle_user_msg_list[-1].content, message)
        with self.assert_database_query_count(8):
            reactivate_user_if_soft_deactivated(long_term_idle_user)
        self.assertFalse(long_term_idle_user.long_term_idle)
        self.assertEqual(
            last_realm_audit_log_entry(RealmAuditLog.USER_SOFT_ACTIVATED).modified_user,
            long_term_idle_user,
        )
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        self.assert_length(idle_user_msg_list, idle_user_msg_count + 1)
        self.assertEqual(idle_user_msg_list[-1].content, message)
        long_term_idle_user.refresh_from_db()
        self.assertEqual(long_term_idle_user.last_active_message_id, message_id)

    def test_add_missing_messages(self) -> None:
        recipient_list = [self.example_user("hamlet"), self.example_user("iago")]
        for user_profile in recipient_list:
            self.subscribe(user_profile, "Denmark")

        sender = self.example_user("iago")
        realm = sender.realm
        sending_client = make_client(name="test suite")
        stream_name = "Denmark"
        stream = get_stream(stream_name, realm)
        topic_name = "foo"

        def send_fake_message(message_content: str, stream: Stream) -> Message:
            """
            The purpose of this helper is to create a Message object without corresponding
            UserMessage rows being created.
            """
            recipient = stream.recipient
            message = Message(
                sender=sender,
                realm=realm,
                recipient=recipient,
                content=message_content,
                date_sent=timezone_now(),
                sending_client=sending_client,
            )
            message.set_topic_name(topic_name)
            message.save()
            return message

        long_term_idle_user = self.example_user("hamlet")
        self.send_stream_message(long_term_idle_user, stream_name)
        with self.assertLogs(logger_string, level="INFO") as info_logs:
            do_soft_deactivate_users([long_term_idle_user])
        self.assertEqual(
            info_logs.output,
            [
                f"INFO:{logger_string}:Soft deactivated user {long_term_idle_user.id}",
                f"INFO:{logger_string}:Soft-deactivated batch of 1 users; 0 remain to process",
            ],
        )

        # Test that add_missing_messages() in simplest case of adding a
        # message for which UserMessage row doesn't exist for this user.
        sent_message = send_fake_message("Test message 1", stream)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        idle_user_msg_count = len(idle_user_msg_list)
        self.assertNotEqual(idle_user_msg_list[-1], sent_message)
        with self.assert_database_query_count(6):
            add_missing_messages(long_term_idle_user)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        self.assert_length(idle_user_msg_list, idle_user_msg_count + 1)
        self.assertEqual(idle_user_msg_list[-1], sent_message)
        long_term_idle_user.refresh_from_db()
        self.assertEqual(long_term_idle_user.last_active_message_id, sent_message.id)

        # Test that add_missing_messages() only adds messages that aren't
        # already present in the UserMessage table. This test works on the
        # fact that previous test just above this added a message but didn't
        # updated the last_active_message_id field for the user.
        sent_message = send_fake_message("Test message 2", stream)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        idle_user_msg_count = len(idle_user_msg_list)
        self.assertNotEqual(idle_user_msg_list[-1], sent_message)
        with self.assert_database_query_count(7):
            add_missing_messages(long_term_idle_user)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        self.assert_length(idle_user_msg_list, idle_user_msg_count + 1)
        self.assertEqual(idle_user_msg_list[-1], sent_message)
        long_term_idle_user.refresh_from_db()
        self.assertEqual(long_term_idle_user.last_active_message_id, sent_message.id)

        # Test UserMessage rows are created correctly in case of stream
        # Subscription was altered by admin while user was away.

        # Test for a public stream.
        sent_message_list = []
        sent_message_list.append(send_fake_message("Test message 3", stream))
        # Alter subscription to stream.
        self.unsubscribe(long_term_idle_user, stream_name)
        send_fake_message("Test message 4", stream)
        self.subscribe(long_term_idle_user, stream_name)
        sent_message_list.append(send_fake_message("Test message 5", stream))
        sent_message_list.reverse()
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        idle_user_msg_count = len(idle_user_msg_list)
        for sent_message in sent_message_list:
            self.assertNotEqual(idle_user_msg_list.pop(), sent_message)
        with self.assert_database_query_count(6):
            add_missing_messages(long_term_idle_user)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        self.assert_length(idle_user_msg_list, idle_user_msg_count + 2)
        for sent_message in sent_message_list:
            self.assertEqual(idle_user_msg_list.pop(), sent_message)
        long_term_idle_user.refresh_from_db()
        self.assertEqual(long_term_idle_user.last_active_message_id, sent_message_list[0].id)

        # Test consecutive subscribe/unsubscribe in a public stream
        sent_message_list = []

        sent_message_list.append(send_fake_message("Test message 6", stream))
        # Unsubscribe from stream and then immediately subscribe back again.
        self.unsubscribe(long_term_idle_user, stream_name)
        self.subscribe(long_term_idle_user, stream_name)
        sent_message_list.append(send_fake_message("Test message 7", stream))
        # Again unsubscribe from stream and send a message.
        # This will make sure that if initially in a unsubscribed state
        # a consecutive subscribe/unsubscribe doesn't misbehave.
        self.unsubscribe(long_term_idle_user, stream_name)
        send_fake_message("Test message 8", stream)
        # Do a subscribe and unsubscribe immediately.
        self.subscribe(long_term_idle_user, stream_name)
        self.unsubscribe(long_term_idle_user, stream_name)

        sent_message_list.reverse()
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        idle_user_msg_count = len(idle_user_msg_list)
        for sent_message in sent_message_list:
            self.assertNotEqual(idle_user_msg_list.pop(), sent_message)
        with self.assert_database_query_count(6):
            add_missing_messages(long_term_idle_user)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        self.assert_length(idle_user_msg_list, idle_user_msg_count + 2)
        for sent_message in sent_message_list:
            self.assertEqual(idle_user_msg_list.pop(), sent_message)
        long_term_idle_user.refresh_from_db()
        self.assertEqual(long_term_idle_user.last_active_message_id, sent_message_list[0].id)

        # Test for when user unsubscribes before soft deactivation
        # (must reactivate them in order to do this).

        do_soft_activate_users([long_term_idle_user])
        self.subscribe(long_term_idle_user, stream_name)
        # Send a real message to update last_active_message_id
        sent_message_id = self.send_stream_message(sender, stream_name, "Test message 9")
        self.unsubscribe(long_term_idle_user, stream_name)
        # Soft deactivate and send another message to the unsubscribed stream.
        with self.assertLogs(logger_string, level="INFO") as info_logs:
            do_soft_deactivate_users([long_term_idle_user])
        self.assertEqual(
            info_logs.output,
            [
                f"INFO:{logger_string}:Soft deactivated user {long_term_idle_user.id}",
                f"INFO:{logger_string}:Soft-deactivated batch of 1 users; 0 remain to process",
            ],
        )
        send_fake_message("Test message 10", stream)

        idle_user_msg_list = get_user_messages(long_term_idle_user)
        idle_user_msg_count = len(idle_user_msg_list)
        self.assertEqual(idle_user_msg_list[-1].id, sent_message_id)
        # There are no streams to fetch missing messages from, so
        # the Message.objects query will be avoided.
        with self.assert_database_query_count(4):
            add_missing_messages(long_term_idle_user)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        # No new UserMessage rows should have been created.
        self.assert_length(idle_user_msg_list, idle_user_msg_count)

        # Note: At this point in this test we have long_term_idle_user
        # unsubscribed from the 'Denmark' stream.

        # Test for a private stream.
        stream_name = "Core"
        private_stream = self.make_stream("Core", invite_only=True)
        self.subscribe(self.example_user("iago"), stream_name)
        sent_message_list = []
        send_fake_message("Test message 11", private_stream)
        self.subscribe(self.example_user("hamlet"), stream_name)
        sent_message_list.append(send_fake_message("Test message 12", private_stream))
        self.unsubscribe(long_term_idle_user, stream_name)
        send_fake_message("Test message 13", private_stream)
        self.subscribe(long_term_idle_user, stream_name)
        sent_message_list.append(send_fake_message("Test message 14", private_stream))
        sent_message_list.reverse()
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        idle_user_msg_count = len(idle_user_msg_list)
        for sent_message in sent_message_list:
            self.assertNotEqual(idle_user_msg_list.pop(), sent_message)
        with self.assert_database_query_count(6):
            add_missing_messages(long_term_idle_user)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        self.assert_length(idle_user_msg_list, idle_user_msg_count + 2)
        for sent_message in sent_message_list:
            self.assertEqual(idle_user_msg_list.pop(), sent_message)
        long_term_idle_user.refresh_from_db()
        self.assertEqual(long_term_idle_user.last_active_message_id, sent_message_list[0].id)

    @mock.patch("zerver.lib.soft_deactivation.BULK_CREATE_BATCH_SIZE", 2)
    def test_add_missing_messages_pagination(self) -> None:
        recipient_list = [self.example_user("hamlet"), self.example_user("iago")]
        stream_name = "Denmark"
        for user_profile in recipient_list:
            self.subscribe(user_profile, stream_name)

        sender = self.example_user("iago")
        long_term_idle_user = self.example_user("hamlet")
        self.send_stream_message(long_term_idle_user, stream_name)
        with self.assertLogs(logger_string, level="INFO") as info_logs:
            do_soft_deactivate_users([long_term_idle_user])
        self.assertEqual(
            info_logs.output,
            [
                f"INFO:{logger_string}:Soft deactivated user {long_term_idle_user.id}",
                f"INFO:{logger_string}:Soft-deactivated batch of 1 users; 0 remain to process",
            ],
        )

        num_new_messages = 5
        message_ids = []
        for _ in range(num_new_messages):
            message_id = self.send_stream_message(sender, stream_name)
            message_ids.append(message_id)

        idle_user_msg_list = get_user_messages(long_term_idle_user)
        idle_user_msg_count = len(idle_user_msg_list)
        with self.assert_database_query_count(10):
            add_missing_messages(long_term_idle_user)
        idle_user_msg_list = get_user_messages(long_term_idle_user)
        self.assert_length(idle_user_msg_list, idle_user_msg_count + num_new_messages)
        long_term_idle_user.refresh_from_db()
        self.assertEqual(long_term_idle_user.last_active_message_id, message_ids[-1])

    def test_user_message_filter(self) -> None:
        # In this test we are basically testing out the logic used out in
        # do_send_messages() in action.py for filtering the messages for which
        # UserMessage rows should be created for a soft-deactivated user.
        AlertWord.objects.all().delete()

        long_term_idle_user = self.example_user("hamlet")
        cordelia = self.example_user("cordelia")
        sender = self.example_user("iago")
        stream_name = "Brand New Stream"
        topic_name = "foo"
        realm_id = cordelia.realm_id

        self.subscribe(long_term_idle_user, stream_name)
        self.subscribe(cordelia, stream_name)
        self.subscribe(sender, stream_name)

        stream_id = get_stream(stream_name, cordelia.realm).id

        def send_stream_message(content: str) -> None:
            self.send_stream_message(sender, stream_name, content, topic_name)

        def send_personal_message(content: str) -> None:
            self.send_personal_message(sender, self.example_user("hamlet"), content)

        self.send_stream_message(long_term_idle_user, stream_name)

        with self.assertLogs(logger_string, level="INFO") as info_logs:
            do_soft_deactivate_users([long_term_idle_user])

        self.assertEqual(
            info_logs.output,
            [
                f"INFO:{logger_string}:Soft deactivated user {long_term_idle_user.id}",
                f"INFO:{logger_string}:Soft-deactivated batch of 1 users; 0 remain to process",
            ],
        )

        def assert_um_count(user: UserProfile, count: int) -> None:
            user_messages = get_user_messages(user)
            self.assert_length(user_messages, count)

        def assert_last_um_content(user: UserProfile, content: str, negate: bool = False) -> None:
            user_messages = get_user_messages(user)
            if negate:
                self.assertNotEqual(user_messages[-1].content, content)
            else:
                self.assertEqual(user_messages[-1].content, content)

        def assert_num_possible_users(
            expected_count: int,
            *,
            possible_stream_wildcard_mention: bool = False,
            topic_participant_user_ids: AbstractSet[int] = set(),
            possibly_mentioned_user_ids: AbstractSet[int] = set(),
        ) -> None:
            self.assertEqual(
                len(
                    get_subscriptions_for_send_message(
                        realm_id=realm_id,
                        stream_id=stream_id,
                        topic_name=topic_name,
                        possible_stream_wildcard_mention=possible_stream_wildcard_mention,
                        topic_participant_user_ids=topic_participant_user_ids,
                        possibly_mentioned_user_ids=possibly_mentioned_user_ids,
                    )
                ),
                expected_count,
            )

        def assert_stream_message_sent_to_idle_user(
            content: str,
            *,
            possible_stream_wildcard_mention: bool = False,
            topic_participant_user_ids: AbstractSet[int] = set(),
            possibly_mentioned_user_ids: AbstractSet[int] = set(),
        ) -> None:
            assert_num_possible_users(
                expected_count=3,
                possible_stream_wildcard_mention=possible_stream_wildcard_mention,
                topic_participant_user_ids=topic_participant_user_ids,
                possibly_mentioned_user_ids=possibly_mentioned_user_ids,
            )
            general_user_msg_count = len(get_user_messages(cordelia))
            soft_deactivated_user_msg_count = len(get_user_messages(long_term_idle_user))
            send_stream_message(content)
            assert_um_count(long_term_idle_user, soft_deactivated_user_msg_count + 1)
            assert_um_count(cordelia, general_user_msg_count + 1)
            assert_last_um_content(long_term_idle_user, content)
            assert_last_um_content(cordelia, content)

        def assert_stream_message_not_sent_to_idle_user(
            content: str,
            *,
            possibly_mentioned_user_ids: AbstractSet[int] = set(),
            false_alarm_row: bool = False,
        ) -> None:
            if false_alarm_row:
                # We will query for our idle user if he has **ANY** alert
                # words, but we won't actually write a UserMessage row until
                # we truly parse the message. We also get false alarms for
                # messages with quoted mentions.
                assert_num_possible_users(
                    3, possibly_mentioned_user_ids=possibly_mentioned_user_ids
                )
            else:
                assert_num_possible_users(2)
            general_user_msg_count = len(get_user_messages(cordelia))
            soft_deactivated_user_msg_count = len(get_user_messages(long_term_idle_user))
            send_stream_message(content)
            assert_um_count(long_term_idle_user, soft_deactivated_user_msg_count)
            assert_um_count(cordelia, general_user_msg_count + 1)
            assert_last_um_content(long_term_idle_user, content, negate=True)
            assert_last_um_content(cordelia, content)

        # Test that sending a message to a stream with soft deactivated user
        # doesn't end up creating UserMessage row for deactivated user.
        assert_stream_message_not_sent_to_idle_user("Test message 1")

        sub = get_subscription(stream_name, long_term_idle_user)

        # Sub settings override user settings.
        sub.push_notifications = True
        sub.save()
        assert_stream_message_sent_to_idle_user("Sub push")

        sub.push_notifications = False
        sub.save()
        assert_stream_message_not_sent_to_idle_user("Sub no push")

        # Let user defaults take over
        sub.push_notifications = None
        sub.save()

        long_term_idle_user.enable_stream_push_notifications = True
        long_term_idle_user.save()
        assert_stream_message_sent_to_idle_user("User push")

        long_term_idle_user.enable_stream_push_notifications = False
        long_term_idle_user.save()
        assert_stream_message_not_sent_to_idle_user("User no push")

        # Sub settings override user settings.
        sub.email_notifications = True
        sub.save()
        assert_stream_message_sent_to_idle_user("Sub email")

        sub.email_notifications = False
        sub.save()
        assert_stream_message_not_sent_to_idle_user("Sub no email")

        # Let user defaults take over
        sub.email_notifications = None
        sub.save()

        long_term_idle_user.enable_stream_email_notifications = True
        long_term_idle_user.save()
        assert_stream_message_sent_to_idle_user("User email")

        long_term_idle_user.enable_stream_email_notifications = False
        long_term_idle_user.save()
        assert_stream_message_not_sent_to_idle_user("User no email")

        # Test sending a direct message to soft deactivated user creates
        # UserMessage row.
        soft_deactivated_user_msg_count = len(get_user_messages(long_term_idle_user))
        message = "Test direct message"
        send_personal_message(message)
        assert_um_count(long_term_idle_user, soft_deactivated_user_msg_count + 1)
        assert_last_um_content(long_term_idle_user, message)

        # Test UserMessage row is created while user is deactivated if
        # user itself is mentioned.
        assert_stream_message_sent_to_idle_user(
            "Test @**King Hamlet** mention",
            possibly_mentioned_user_ids={long_term_idle_user.id},
        )

        assert_stream_message_not_sent_to_idle_user(
            "Test `@**King Hamlet**` mention",
            possibly_mentioned_user_ids={long_term_idle_user.id},
            false_alarm_row=True,
        )

        # Test UserMessage row is not created while user is deactivated if
        # anyone is mentioned but the user.
        assert_stream_message_not_sent_to_idle_user("Test @**Cordelia, Lear's daughter**  mention")

        # Test UserMessage row is created while user is deactivated if
        # there is a stream wildcard mention such as @all or @everyone
        assert_stream_message_sent_to_idle_user(
            "Test @**all** mention", possible_stream_wildcard_mention=True
        )
        assert_stream_message_sent_to_idle_user(
            "Test @**everyone** mention", possible_stream_wildcard_mention=True
        )
        assert_stream_message_sent_to_idle_user(
            "Test @**stream** mention", possible_stream_wildcard_mention=True
        )
        assert_stream_message_not_sent_to_idle_user("Test @**bogus** mention")

        # Test UserMessage row is created while user is deactivated if
        # there is a topic wildcard mention i.e. @topic
        do_soft_activate_users([long_term_idle_user])
        self.send_stream_message(long_term_idle_user, stream_name, "Hi", topic_name)
        topic_participant_user_ids = {long_term_idle_user.id}

        do_soft_deactivate_users([long_term_idle_user])
        assert_stream_message_sent_to_idle_user(
            "Test @**topic** mention", topic_participant_user_ids=topic_participant_user_ids
        )

        # Test UserMessage row is created while user is deactivated if there
        # is a alert word in message.
        do_add_alert_words(long_term_idle_user, ["test_alert_word"])
        assert_stream_message_sent_to_idle_user("Testing test_alert_word")

        do_add_alert_words(cordelia, ["cordelia"])
        assert_stream_message_not_sent_to_idle_user("cordelia", false_alarm_row=True)

        # Test UserMessage row is not created while user is deactivated if
        # message is a me message.
        assert_stream_message_not_sent_to_idle_user("/me says test", false_alarm_row=True)

        # Sanity check after removing the alert word for Hamlet.
        AlertWord.objects.filter(user_profile=long_term_idle_user).delete()
        assert_stream_message_not_sent_to_idle_user("no alert words")