Merge branch 'infraction-durations' of https://github.com/python-discord/bot into infraction-durations

4 files changed, 112 insertions, 140 deletions

diff --git a/tests/base.py b/tests/base.py
index 5e304ea9d..4863a1821 100644
--- a/tests/base.py
+++ b/tests/base.py
@@ -4,6 +4,7 @@ from contextlib import contextmanager
 from typing import Dict
 
 import discord
+from async_rediscache import RedisSession
 from discord.ext import commands
 
 from bot.log import get_logger
@@ -104,3 +105,26 @@ class CommandTestCase(unittest.IsolatedAsyncioTestCase):
             await cmd.can_run(ctx)
 
         self.assertCountEqual(permissions.keys(), cm.exception.missing_permissions)
+
+
+class RedisTestCase(unittest.IsolatedAsyncioTestCase):
+    """
+    Use this as a base class for any test cases that require a redis session.
+
+    This will prepare a fresh redis instance for each test function, and will
+    not make any assertions on its own. Tests can mutate the instance as they wish.
+    """
+
+    session = None
+
+    async def flush(self):
+        """Flush everything from the redis database to prevent carry-overs between tests."""
+        await self.session.client.flushall()
+
+    async def asyncSetUp(self):
+        self.session = await RedisSession(use_fakeredis=True).connect()
+        await self.flush()
+
+    async def asyncTearDown(self):
+        if self.session:
+            await self.session.client.close()
diff --git a/tests/bot/exts/backend/test_error_handler.py b/tests/bot/exts/backend/test_error_handler.py
index 0a58126e7..7562f6aa8 100644
--- a/tests/bot/exts/backend/test_error_handler.py
+++ b/tests/bot/exts/backend/test_error_handler.py
@@ -5,7 +5,7 @@ from botcore.site_api import ResponseCodeError
 from discord.ext.commands import errors
 
 from bot.errors import InvalidInfractedUserError, LockedResourceError
-from bot.exts.backend.error_handler import ErrorHandler, setup
+from bot.exts.backend import error_handler
 from bot.exts.info.tags import Tags
 from bot.exts.moderation.silence import Silence
 from bot.utils.checks import InWhitelistCheckFailure
@@ -18,14 +18,14 @@ class ErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
     def setUp(self):
         self.bot = MockBot()
         self.ctx = MockContext(bot=self.bot)
+        self.cog = error_handler.ErrorHandler(self.bot)
 
     async def test_error_handler_already_handled(self):
         """Should not do anything when error is already handled by local error handler."""
         self.ctx.reset_mock()
-        cog = ErrorHandler(self.bot)
         error = errors.CommandError()
         error.handled = "foo"
-        self.assertIsNone(await cog.on_command_error(self.ctx, error))
+        self.assertIsNone(await self.cog.on_command_error(self.ctx, error))
         self.ctx.send.assert_not_awaited()
 
     async def test_error_handler_command_not_found_error_not_invoked_by_handler(self):
@@ -45,28 +45,27 @@ class ErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
                 "called_try_get_tag": True
             }
         )
-        cog = ErrorHandler(self.bot)
-        cog.try_silence = AsyncMock()
-        cog.try_get_tag = AsyncMock()
-        cog.try_run_eval = AsyncMock(return_value=False)
+        self.cog.try_silence = AsyncMock()
+        self.cog.try_get_tag = AsyncMock()
+        self.cog.try_run_eval = AsyncMock(return_value=False)
 
         for case in test_cases:
             with self.subTest(try_silence_return=case["try_silence_return"], try_get_tag=case["called_try_get_tag"]):
                 self.ctx.reset_mock()
-                cog.try_silence.reset_mock(return_value=True)
-                cog.try_get_tag.reset_mock()
+                self.cog.try_silence.reset_mock(return_value=True)
+                self.cog.try_get_tag.reset_mock()
 
-                cog.try_silence.return_value = case["try_silence_return"]
+                self.cog.try_silence.return_value = case["try_silence_return"]
                 self.ctx.channel.id = 1234
 
-                self.assertIsNone(await cog.on_command_error(self.ctx, error))
+                self.assertIsNone(await self.cog.on_command_error(self.ctx, error))
 
                 if case["try_silence_return"]:
-                    cog.try_get_tag.assert_not_awaited()
-                    cog.try_silence.assert_awaited_once()
+                    self.cog.try_get_tag.assert_not_awaited()
+                    self.cog.try_silence.assert_awaited_once()
                 else:
-                    cog.try_silence.assert_awaited_once()
-                    cog.try_get_tag.assert_awaited_once()
+                    self.cog.try_silence.assert_awaited_once()
+                    self.cog.try_get_tag.assert_awaited_once()
 
                 self.ctx.send.assert_not_awaited()
 
@@ -74,59 +73,54 @@ class ErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
         """Should do nothing when error is `CommandNotFound` and have attribute `invoked_from_error_handler`."""
         ctx = MockContext(bot=self.bot, invoked_from_error_handler=True)
 
-        cog = ErrorHandler(self.bot)
-        cog.try_silence = AsyncMock()
-        cog.try_get_tag = AsyncMock()
-        cog.try_run_eval = AsyncMock()
+        self.cog.try_silence = AsyncMock()
+        self.cog.try_get_tag = AsyncMock()
+        self.cog.try_run_eval = AsyncMock()
 
         error = errors.CommandNotFound()
 
-        self.assertIsNone(await cog.on_command_error(ctx, error))
+        self.assertIsNone(await self.cog.on_command_error(ctx, error))
 
-        cog.try_silence.assert_not_awaited()
-        cog.try_get_tag.assert_not_awaited()
-        cog.try_run_eval.assert_not_awaited()
+        self.cog.try_silence.assert_not_awaited()
+        self.cog.try_get_tag.assert_not_awaited()
+        self.cog.try_run_eval.assert_not_awaited()
         self.ctx.send.assert_not_awaited()
 
     async def test_error_handler_user_input_error(self):
         """Should await `ErrorHandler.handle_user_input_error` when error is `UserInputError`."""
         self.ctx.reset_mock()
-        cog = ErrorHandler(self.bot)
-        cog.handle_user_input_error = AsyncMock()
+        self.cog.handle_user_input_error = AsyncMock()
         error = errors.UserInputError()
-        self.assertIsNone(await cog.on_command_error(self.ctx, error))
-        cog.handle_user_input_error.assert_awaited_once_with(self.ctx, error)
+        self.assertIsNone(await self.cog.on_command_error(self.ctx, error))
+        self.cog.handle_user_input_error.assert_awaited_once_with(self.ctx, error)
 
     async def test_error_handler_check_failure(self):
         """Should await `ErrorHandler.handle_check_failure` when error is `CheckFailure`."""
         self.ctx.reset_mock()
-        cog = ErrorHandler(self.bot)
-        cog.handle_check_failure = AsyncMock()
+        self.cog.handle_check_failure = AsyncMock()
         error = errors.CheckFailure()
-        self.assertIsNone(await cog.on_command_error(self.ctx, error))
-        cog.handle_check_failure.assert_awaited_once_with(self.ctx, error)
+        self.assertIsNone(await self.cog.on_command_error(self.ctx, error))
+        self.cog.handle_check_failure.assert_awaited_once_with(self.ctx, error)
 
     async def test_error_handler_command_on_cooldown(self):
         """Should send error with `ctx.send` when error is `CommandOnCooldown`."""
         self.ctx.reset_mock()
-        cog = ErrorHandler(self.bot)
         error = errors.CommandOnCooldown(10, 9, type=None)
-        self.assertIsNone(await cog.on_command_error(self.ctx, error))
+        self.assertIsNone(await self.cog.on_command_error(self.ctx, error))
         self.ctx.send.assert_awaited_once_with(error)
 
     async def test_error_handler_command_invoke_error(self):
         """Should call `handle_api_error` or `handle_unexpected_error` depending on original error."""
-        cog = ErrorHandler(self.bot)
-        cog.handle_api_error = AsyncMock()
-        cog.handle_unexpected_error = AsyncMock()
+        self.cog.handle_api_error = AsyncMock()
+        self.cog.handle_unexpected_error = AsyncMock()
         test_cases = (
             {
                 "args": (self.ctx, errors.CommandInvokeError(ResponseCodeError(AsyncMock()))),
-                "expect_mock_call": cog.handle_api_error
+                "expect_mock_call": self.cog.handle_api_error
             },
             {
                 "args": (self.ctx, errors.CommandInvokeError(TypeError)),
-                "expect_mock_call": cog.handle_unexpected_error
+                "expect_mock_call": self.cog.handle_unexpected_error
             },
             {
                 "args": (self.ctx, errors.CommandInvokeError(LockedResourceError("abc", "test"))),
@@ -141,7 +135,7 @@ class ErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
         for case in test_cases:
             with self.subTest(args=case["args"], expect_mock_call=case["expect_mock_call"]):
                 self.ctx.send.reset_mock()
-                self.assertIsNone(await cog.on_command_error(*case["args"]))
+                self.assertIsNone(await self.cog.on_command_error(*case["args"]))
                 if case["expect_mock_call"] == "send":
                     self.ctx.send.assert_awaited_once()
                 else:
@@ -151,29 +145,27 @@ class ErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
 
     async def test_error_handler_conversion_error(self):
         """Should call `handle_api_error` or `handle_unexpected_error` depending on original error."""
-        cog = ErrorHandler(self.bot)
-        cog.handle_api_error = AsyncMock()
-        cog.handle_unexpected_error = AsyncMock()
+        self.cog.handle_api_error = AsyncMock()
+        self.cog.handle_unexpected_error = AsyncMock()
         cases = (
             {
                 "error": errors.ConversionError(AsyncMock(), ResponseCodeError(AsyncMock())),
-                "mock_function_to_call": cog.handle_api_error
+                "mock_function_to_call": self.cog.handle_api_error
             },
             {
                 "error": errors.ConversionError(AsyncMock(), TypeError),
-                "mock_function_to_call": cog.handle_unexpected_error
+                "mock_function_to_call": self.cog.handle_unexpected_error
             }
         )
 
         for case in cases:
             with self.subTest(**case):
-                self.assertIsNone(await cog.on_command_error(self.ctx, case["error"]))
+                self.assertIsNone(await self.cog.on_command_error(self.ctx, case["error"]))
                 case["mock_function_to_call"].assert_awaited_once_with(self.ctx, case["error"].original)
 
     async def test_error_handler_two_other_errors(self):
         """Should call `handle_unexpected_error` if error is `MaxConcurrencyReached` or `ExtensionError`."""
-        cog = ErrorHandler(self.bot)
-        cog.handle_unexpected_error = AsyncMock()
+        self.cog.handle_unexpected_error = AsyncMock()
         errs = (
             errors.MaxConcurrencyReached(1, MagicMock()),
             errors.ExtensionError(name="foo")
@@ -181,16 +173,15 @@ class ErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
 
         for err in errs:
             with self.subTest(error=err):
-                cog.handle_unexpected_error.reset_mock()
-                self.assertIsNone(await cog.on_command_error(self.ctx, err))
-                cog.handle_unexpected_error.assert_awaited_once_with(self.ctx, err)
+                self.cog.handle_unexpected_error.reset_mock()
+                self.assertIsNone(await self.cog.on_command_error(self.ctx, err))
+                self.cog.handle_unexpected_error.assert_awaited_once_with(self.ctx, err)
 
     @patch("bot.exts.backend.error_handler.log")
     async def test_error_handler_other_errors(self, log_mock):
         """Should `log.debug` other errors."""
-        cog = ErrorHandler(self.bot)
         error = errors.DisabledCommand()  # Use this just as a other error
-        self.assertIsNone(await cog.on_command_error(self.ctx, error))
+        self.assertIsNone(await self.cog.on_command_error(self.ctx, error))
         log_mock.debug.assert_called_once()
 
 
@@ -202,7 +193,7 @@ class TrySilenceTests(unittest.IsolatedAsyncioTestCase):
         self.silence = Silence(self.bot)
         self.bot.get_command.return_value = self.silence.silence
         self.ctx = MockContext(bot=self.bot)
-        self.cog = ErrorHandler(self.bot)
+        self.cog = error_handler.ErrorHandler(self.bot)
 
     async def test_try_silence_context_invoked_from_error_handler(self):
         """Should set `Context.invoked_from_error_handler` to `True`."""
@@ -334,7 +325,7 @@ class TryGetTagTests(unittest.IsolatedAsyncioTestCase):
         self.bot = MockBot()
         self.ctx = MockContext()
         self.tag = Tags(self.bot)
-        self.cog = ErrorHandler(self.bot)
+        self.cog = error_handler.ErrorHandler(self.bot)
         self.bot.get_command.return_value = self.tag.get_command
 
     async def test_try_get_tag_get_command(self):
@@ -399,7 +390,7 @@ class IndividualErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
     def setUp(self):
         self.bot = MockBot()
         self.ctx = MockContext(bot=self.bot)
-        self.cog = ErrorHandler(self.bot)
+        self.cog = error_handler.ErrorHandler(self.bot)
 
     async def test_handle_input_error_handler_errors(self):
         """Should handle each error probably."""
@@ -555,5 +546,5 @@ class ErrorHandlerSetupTests(unittest.IsolatedAsyncioTestCase):
     async def test_setup(self):
         """Should call `bot.add_cog` with `ErrorHandler`."""
         bot = MockBot()
-        await setup(bot)
+        await error_handler.setup(bot)
         bot.add_cog.assert_awaited_once()
diff --git a/tests/bot/exts/moderation/test_incidents.py b/tests/bot/exts/moderation/test_incidents.py
index cfe0c4b03..97682163f 100644
--- a/tests/bot/exts/moderation/test_incidents.py
+++ b/tests/bot/exts/moderation/test_incidents.py
@@ -8,11 +8,11 @@ from unittest.mock import AsyncMock, MagicMock, Mock, call, patch
 
 import aiohttp
 import discord
-from async_rediscache import RedisSession
 
 from bot.constants import Colours
 from bot.exts.moderation import incidents
 from bot.utils.messages import format_user
+from tests.base import RedisTestCase
 from tests.helpers import (
     MockAsyncWebhook, MockAttachment, MockBot, MockMember, MockMessage, MockReaction, MockRole, MockTextChannel,
     MockUser
@@ -270,7 +270,7 @@ class TestAddSignals(unittest.IsolatedAsyncioTestCase):
         self.incident.add_reaction.assert_not_called()
 
 
-class TestIncidents(unittest.IsolatedAsyncioTestCase):
+class TestIncidents(RedisTestCase):
     """
     Tests for bound methods of the `Incidents` cog.
 
@@ -279,22 +279,6 @@ class TestIncidents(unittest.IsolatedAsyncioTestCase):
     the instance as they wish.
     """
 
-    session = None
-
-    async def flush(self):
-        """Flush everything from the database to prevent carry-overs between tests."""
-        with await self.session.pool as connection:
-            await connection.flushall()
-
-    async def asyncSetUp(self):  # noqa: N802
-        self.session = RedisSession(use_fakeredis=True)
-        await self.session.connect()
-        await self.flush()
-
-    async def asyncTearDown(self):  # noqa: N802
-        if self.session:
-            await self.session.close()
-
     def setUp(self):
         """
         Prepare a fresh `Incidents` instance for each test.
@@ -656,7 +640,7 @@ class TestOnRawReactionAdd(TestIncidents):
             emoji="reaction",
         )
 
-    async def asyncSetUp(self):  # noqa: N802
+    async def asyncSetUp(self):
         """
         Prepare an empty task and assign it as `crawl_task`.
 
diff --git a/tests/bot/exts/moderation/test_silence.py b/tests/bot/exts/moderation/test_silence.py
index 65aecad28..2622f46a7 100644
--- a/tests/bot/exts/moderation/test_silence.py
+++ b/tests/bot/exts/moderation/test_silence.py
@@ -1,4 +1,3 @@
-import asyncio
 import itertools
 import unittest
 from datetime import datetime, timezone
@@ -6,31 +5,15 @@ from typing import List, Tuple
 from unittest import mock
 from unittest.mock import AsyncMock, Mock
 
-from async_rediscache import RedisSession
 from discord import PermissionOverwrite
 
 from bot.constants import Channels, Guild, MODERATION_ROLES, Roles
 from bot.exts.moderation import silence
+from tests.base import RedisTestCase
 from tests.helpers import (
     MockBot, MockContext, MockGuild, MockMember, MockRole, MockTextChannel, MockVoiceChannel, autospec
 )
 
-redis_session = None
-redis_loop = asyncio.get_event_loop()
-
-
-def setUpModule():  # noqa: N802
-    """Create and connect to the fakeredis session."""
-    global redis_session
-    redis_session = RedisSession(use_fakeredis=True)
-    redis_loop.run_until_complete(redis_session.connect())
-
-
-def tearDownModule():  # noqa: N802
-    """Close the fakeredis session."""
-    if redis_session:
-        redis_loop.run_until_complete(redis_session.close())
-
 
 # Have to subclass it because builtins can't be patched.
 class PatchedDatetime(datetime):
@@ -39,8 +22,24 @@ class PatchedDatetime(datetime):
     now = mock.create_autospec(datetime, "now")
 
 
-class SilenceNotifierTests(unittest.IsolatedAsyncioTestCase):
+class SilenceTest(RedisTestCase):
+    """A base class for Silence tests that correctly sets up the cog and redis."""
+
+    @autospec(silence, "Scheduler", pass_mocks=False)
+    @autospec(silence.Silence, "_reschedule", pass_mocks=False)
+    def setUp(self) -> None:
+        self.bot = MockBot(get_channel=lambda _id: MockTextChannel(id=_id))
+        self.cog = silence.Silence(self.bot)
+
+    @autospec(silence, "SilenceNotifier", pass_mocks=False)
+    async def asyncSetUp(self) -> None:
+        await super().asyncSetUp()
+        await self.cog.cog_load()  # Populate instance attributes.
+
+
+class SilenceNotifierTests(SilenceTest):
     def setUp(self) -> None:
+        super().setUp()
         self.alert_channel = MockTextChannel()
         self.notifier = silence.SilenceNotifier(self.alert_channel)
         self.notifier.stop = self.notifier_stop_mock = Mock()
@@ -105,34 +104,24 @@ class SilenceNotifierTests(unittest.IsolatedAsyncioTestCase):
 
 
 @autospec(silence.Silence, "previous_overwrites", "unsilence_timestamps", pass_mocks=False)
-class SilenceCogTests(unittest.IsolatedAsyncioTestCase):
+class SilenceCogTests(SilenceTest):
     """Tests for the general functionality of the Silence cog."""
 
-    @autospec(silence, "Scheduler", pass_mocks=False)
-    def setUp(self) -> None:
-        self.bot = MockBot()
-        self.cog = silence.Silence(self.bot)
-
     @autospec(silence, "SilenceNotifier", pass_mocks=False)
     async def test_cog_load_got_guild(self):
         """Bot got guild after it became available."""
-        await self.cog.cog_load()
         self.bot.wait_until_guild_available.assert_awaited_once()
         self.bot.get_guild.assert_called_once_with(Guild.id)
 
     @autospec(silence, "SilenceNotifier", pass_mocks=False)
     async def test_cog_load_got_channels(self):
         """Got channels from bot."""
-        self.bot.get_channel.side_effect = lambda id_: MockTextChannel(id=id_)
-
         await self.cog.cog_load()
         self.assertEqual(self.cog._mod_alerts_channel.id, Channels.mod_alerts)
 
     @autospec(silence, "SilenceNotifier")
     async def test_cog_load_got_notifier(self, notifier):
         """Notifier was started with channel."""
-        self.bot.get_channel.side_effect = lambda id_: MockTextChannel(id=id_)
-
         await self.cog.cog_load()
         notifier.assert_called_once_with(MockTextChannel(id=Channels.mod_log))
         self.assertEqual(self.cog.notifier, notifier.return_value)
@@ -245,15 +234,9 @@ class SilenceCogTests(unittest.IsolatedAsyncioTestCase):
             self.assertEqual(member.move_to.call_count, 1 if member == failing_member else 2)
 
 
-class SilenceArgumentParserTests(unittest.IsolatedAsyncioTestCase):
+class SilenceArgumentParserTests(SilenceTest):
     """Tests for the silence argument parser utility function."""
 
-    def setUp(self):
-        self.bot = MockBot()
-        self.cog = silence.Silence(self.bot)
-        self.cog._init_task = asyncio.Future()
-        self.cog._init_task.set_result(None)
-
     @autospec(silence.Silence, "send_message", pass_mocks=False)
     @autospec(silence.Silence, "_set_silence_overwrites", return_value=False, pass_mocks=False)
     @autospec(silence.Silence, "parse_silence_args")
@@ -321,17 +304,19 @@ class SilenceArgumentParserTests(unittest.IsolatedAsyncioTestCase):
 
 
 @autospec(silence.Silence, "previous_overwrites", "unsilence_timestamps", pass_mocks=False)
-class RescheduleTests(unittest.IsolatedAsyncioTestCase):
+class RescheduleTests(RedisTestCase):
     """Tests for the rescheduling of cached unsilences."""
 
-    @autospec(silence, "Scheduler", "SilenceNotifier", pass_mocks=False)
-    def setUp(self):
+    @autospec(silence, "Scheduler", pass_mocks=False)
+    def setUp(self) -> None:
         self.bot = MockBot()
         self.cog = silence.Silence(self.bot)
         self.cog._unsilence_wrapper = mock.create_autospec(self.cog._unsilence_wrapper)
 
-        with mock.patch.object(self.cog, "_reschedule", autospec=True):
-            asyncio.run(self.cog.cog_load())  # Populate instance attributes.
+    @autospec(silence, "SilenceNotifier", pass_mocks=False)
+    async def asyncSetUp(self) -> None:
+        await super().asyncSetUp()
+        await self.cog.cog_load()  # Populate instance attributes.
 
     async def test_skipped_missing_channel(self):
         """Did nothing because the channel couldn't be retrieved."""
@@ -406,22 +391,14 @@ def voice_sync_helper(function):
 
 
 @autospec(silence.Silence, "previous_overwrites", "unsilence_timestamps", pass_mocks=False)
-class SilenceTests(unittest.IsolatedAsyncioTestCase):
+class SilenceTests(SilenceTest):
     """Tests for the silence command and its related helper methods."""
 
-    @autospec(silence.Silence, "_reschedule", pass_mocks=False)
-    @autospec(silence, "Scheduler", "SilenceNotifier", pass_mocks=False)
     def setUp(self) -> None:
-        self.bot = MockBot(get_channel=lambda _: MockTextChannel())
-        self.cog = silence.Silence(self.bot)
-        self.cog._init_task = asyncio.Future()
-        self.cog._init_task.set_result(None)
+        super().setUp()
 
         # Avoid unawaited coroutine warnings.
         self.cog.scheduler.schedule_later.side_effect = lambda delay, task_id, coro: coro.close()
-
-        asyncio.run(self.cog.cog_load())  # Populate instance attributes.
-
         self.text_channel = MockTextChannel()
         self.text_overwrite = PermissionOverwrite(
             send_messages=True,
@@ -679,24 +656,13 @@ class SilenceTests(unittest.IsolatedAsyncioTestCase):
 
 
 @autospec(silence.Silence, "unsilence_timestamps", pass_mocks=False)
-class UnsilenceTests(unittest.IsolatedAsyncioTestCase):
+class UnsilenceTests(SilenceTest):
     """Tests for the unsilence command and its related helper methods."""
 
-    @autospec(silence.Silence, "_reschedule", pass_mocks=False)
-    @autospec(silence, "Scheduler", "SilenceNotifier", pass_mocks=False)
     def setUp(self) -> None:
-        self.bot = MockBot(get_channel=lambda _: MockTextChannel())
-        self.cog = silence.Silence(self.bot)
-        self.cog._init_task = asyncio.Future()
-        self.cog._init_task.set_result(None)
-
-        overwrites_cache = mock.create_autospec(self.cog.previous_overwrites, spec_set=True)
-        self.cog.previous_overwrites = overwrites_cache
-
-        asyncio.run(self.cog.cog_load())  # Populate instance attributes.
+        super().setUp()
 
         self.cog.scheduler.__contains__.return_value = True
-        overwrites_cache.get.return_value = '{"send_messages": true, "add_reactions": false}'
         self.text_channel = MockTextChannel()
         self.text_overwrite = PermissionOverwrite(send_messages=False, add_reactions=False)
         self.text_channel.overwrites_for.return_value = self.text_overwrite
@@ -705,6 +671,13 @@ class UnsilenceTests(unittest.IsolatedAsyncioTestCase):
         self.voice_overwrite = PermissionOverwrite(connect=True, speak=True)
         self.voice_channel.overwrites_for.return_value = self.voice_overwrite
 
+    async def asyncSetUp(self) -> None:
+        await super().asyncSetUp()
+        overwrites_cache = mock.create_autospec(self.cog.previous_overwrites, spec_set=True)
+        self.cog.previous_overwrites = overwrites_cache
+
+        overwrites_cache.get.return_value = '{"send_messages": true, "add_reactions": false}'
+
     async def test_sent_correct_message(self):
         """Appropriate failure/success message was sent by the command."""
         unsilenced_overwrite = PermissionOverwrite(send_messages=True, add_reactions=True)