Merge branch 'master' into antimalware-logging

23 files changed, 443 insertions, 190 deletions

diff --git a/tests/bot/cogs/sync/test_base.py b/tests/bot/cogs/sync/test_base.py
index e6a6f9688..fe0594efe 100644
--- a/tests/bot/cogs/sync/test_base.py
+++ b/tests/bot/cogs/sync/test_base.py
@@ -13,8 +13,8 @@ class TestSyncer(Syncer):
     """Syncer subclass with mocks for abstract methods for testing purposes."""
 
     name = "test"
-    _get_diff = helpers.AsyncMock()
-    _sync = helpers.AsyncMock()
+    _get_diff = mock.AsyncMock()
+    _sync = mock.AsyncMock()
 
 
 class SyncerBaseTests(unittest.TestCase):
@@ -29,7 +29,7 @@ class SyncerBaseTests(unittest.TestCase):
             Syncer(self.bot)
 
 
-class SyncerSendPromptTests(unittest.TestCase):
+class SyncerSendPromptTests(unittest.IsolatedAsyncioTestCase):
     """Tests for sending the sync confirmation prompt."""
 
     def setUp(self):
@@ -61,7 +61,6 @@ class SyncerSendPromptTests(unittest.TestCase):
 
         return mock_channel, mock_message
 
-    @helpers.async_test
     async def test_send_prompt_edits_and_returns_message(self):
         """The given message should be edited to display the prompt and then should be returned."""
         msg = helpers.MockMessage()
@@ -71,7 +70,6 @@ class SyncerSendPromptTests(unittest.TestCase):
         self.assertIn("content", msg.edit.call_args[1])
         self.assertEqual(ret_val, msg)
 
-    @helpers.async_test
     async def test_send_prompt_gets_dev_core_channel(self):
         """The dev-core channel should be retrieved if an extant message isn't given."""
         subtests = (
@@ -84,9 +82,8 @@ class SyncerSendPromptTests(unittest.TestCase):
                 mock_()
                 await self.syncer._send_prompt()
 
-                method.assert_called_once_with(constants.Channels.devcore)
+                method.assert_called_once_with(constants.Channels.dev_core)
 
-    @helpers.async_test
     async def test_send_prompt_returns_None_if_channel_fetch_fails(self):
         """None should be returned if there's an HTTPException when fetching the channel."""
         self.bot.get_channel.return_value = None
@@ -96,7 +93,6 @@ class SyncerSendPromptTests(unittest.TestCase):
 
         self.assertIsNone(ret_val)
 
-    @helpers.async_test
     async def test_send_prompt_sends_and_returns_new_message_if_not_given(self):
         """A new message mentioning core devs should be sent and returned if message isn't given."""
         for mock_ in (self.mock_get_channel, self.mock_fetch_channel):
@@ -108,7 +104,6 @@ class SyncerSendPromptTests(unittest.TestCase):
                 self.assertIn(self.syncer._CORE_DEV_MENTION, mock_channel.send.call_args[0][0])
                 self.assertEqual(ret_val, mock_message)
 
-    @helpers.async_test
     async def test_send_prompt_adds_reactions(self):
         """The message should have reactions for confirmation added."""
         extant_message = helpers.MockMessage()
@@ -129,13 +124,13 @@ class SyncerSendPromptTests(unittest.TestCase):
                 mock_message.add_reaction.assert_has_calls(calls)
 
 
-class SyncerConfirmationTests(unittest.TestCase):
+class SyncerConfirmationTests(unittest.IsolatedAsyncioTestCase):
     """Tests for waiting for a sync confirmation reaction on the prompt."""
 
     def setUp(self):
         self.bot = helpers.MockBot()
         self.syncer = TestSyncer(self.bot)
-        self.core_dev_role = helpers.MockRole(id=constants.Roles.core_developer)
+        self.core_dev_role = helpers.MockRole(id=constants.Roles.core_developers)
 
     @staticmethod
     def get_message_reaction(emoji):
@@ -211,7 +206,6 @@ class SyncerConfirmationTests(unittest.TestCase):
                 ret_val = self.syncer._reaction_check(*args)
                 self.assertFalse(ret_val)
 
-    @helpers.async_test
     async def test_wait_for_confirmation(self):
         """The message should always be edited and only return True if the emoji is a check mark."""
         subtests = (
@@ -251,14 +245,13 @@ class SyncerConfirmationTests(unittest.TestCase):
                     self.assertIs(actual_return, ret_val)
 
 
-class SyncerSyncTests(unittest.TestCase):
+class SyncerSyncTests(unittest.IsolatedAsyncioTestCase):
     """Tests for main function orchestrating the sync."""
 
     def setUp(self):
         self.bot = helpers.MockBot(user=helpers.MockMember(bot=True))
         self.syncer = TestSyncer(self.bot)
 
-    @helpers.async_test
     async def test_sync_respects_confirmation_result(self):
         """The sync should abort if confirmation fails and continue if confirmed."""
         mock_message = helpers.MockMessage()
@@ -274,7 +267,7 @@ class SyncerSyncTests(unittest.TestCase):
 
                 diff = _Diff({1, 2, 3}, {4, 5}, None)
                 self.syncer._get_diff.return_value = diff
-                self.syncer._get_confirmation_result = helpers.AsyncMock(
+                self.syncer._get_confirmation_result = mock.AsyncMock(
                     return_value=(confirmed, message)
                 )
 
@@ -289,7 +282,6 @@ class SyncerSyncTests(unittest.TestCase):
                 else:
                     self.syncer._sync.assert_not_called()
 
-    @helpers.async_test
     async def test_sync_diff_size(self):
         """The diff size should be correctly calculated."""
         subtests = (
@@ -303,7 +295,7 @@ class SyncerSyncTests(unittest.TestCase):
             with self.subTest(size=size, diff=diff):
                 self.syncer._get_diff.reset_mock()
                 self.syncer._get_diff.return_value = diff
-                self.syncer._get_confirmation_result = helpers.AsyncMock(return_value=(False, None))
+                self.syncer._get_confirmation_result = mock.AsyncMock(return_value=(False, None))
 
                 guild = helpers.MockGuild()
                 await self.syncer.sync(guild)
@@ -312,7 +304,6 @@ class SyncerSyncTests(unittest.TestCase):
                 self.syncer._get_confirmation_result.assert_called_once()
                 self.assertEqual(self.syncer._get_confirmation_result.call_args[0][0], size)
 
-    @helpers.async_test
     async def test_sync_message_edited(self):
         """The message should be edited if one was sent, even if the sync has an API error."""
         subtests = (
@@ -324,7 +315,7 @@ class SyncerSyncTests(unittest.TestCase):
         for message, side_effect, should_edit in subtests:
             with self.subTest(message=message, side_effect=side_effect, should_edit=should_edit):
                 self.syncer._sync.side_effect = side_effect
-                self.syncer._get_confirmation_result = helpers.AsyncMock(
+                self.syncer._get_confirmation_result = mock.AsyncMock(
                     return_value=(True, message)
                 )
 
@@ -335,7 +326,6 @@ class SyncerSyncTests(unittest.TestCase):
                     message.edit.assert_called_once()
                     self.assertIn("content", message.edit.call_args[1])
 
-    @helpers.async_test
     async def test_sync_confirmation_context_redirect(self):
         """If ctx is given, a new message should be sent and author should be ctx's author."""
         mock_member = helpers.MockMember()
@@ -349,7 +339,10 @@ class SyncerSyncTests(unittest.TestCase):
                 if ctx is not None:
                     ctx.send.return_value = message
 
-                self.syncer._get_confirmation_result = helpers.AsyncMock(return_value=(False, None))
+                # Make sure `_get_diff` returns a MagicMock, not an AsyncMock
+                self.syncer._get_diff.return_value = mock.MagicMock()
+
+                self.syncer._get_confirmation_result = mock.AsyncMock(return_value=(False, None))
 
                 guild = helpers.MockGuild()
                 await self.syncer.sync(guild, ctx)
@@ -362,16 +355,15 @@ class SyncerSyncTests(unittest.TestCase):
                 self.assertEqual(self.syncer._get_confirmation_result.call_args[0][2], message)
 
     @mock.patch.object(constants.Sync, "max_diff", new=3)
-    @helpers.async_test
     async def test_confirmation_result_small_diff(self):
         """Should always return True and the given message if the diff size is too small."""
         author = helpers.MockMember()
         expected_message = helpers.MockMessage()
 
-        for size in (3, 2):
+        for size in (3, 2):  # pragma: no cover
             with self.subTest(size=size):
-                self.syncer._send_prompt = helpers.AsyncMock()
-                self.syncer._wait_for_confirmation = helpers.AsyncMock()
+                self.syncer._send_prompt = mock.AsyncMock()
+                self.syncer._wait_for_confirmation = mock.AsyncMock()
 
                 coro = self.syncer._get_confirmation_result(size, author, expected_message)
                 result, actual_message = await coro
@@ -382,7 +374,6 @@ class SyncerSyncTests(unittest.TestCase):
                 self.syncer._wait_for_confirmation.assert_not_called()
 
     @mock.patch.object(constants.Sync, "max_diff", new=3)
-    @helpers.async_test
     async def test_confirmation_result_large_diff(self):
         """Should return True if confirmed and False if _send_prompt fails or aborted."""
         author = helpers.MockMember()
@@ -394,10 +385,10 @@ class SyncerSyncTests(unittest.TestCase):
             (False, mock_message, False, "aborted"),
         )
 
-        for expected_result, expected_message, confirmed, msg in subtests:
+        for expected_result, expected_message, confirmed, msg in subtests:  # pragma: no cover
             with self.subTest(msg=msg):
-                self.syncer._send_prompt = helpers.AsyncMock(return_value=expected_message)
-                self.syncer._wait_for_confirmation = helpers.AsyncMock(return_value=confirmed)
+                self.syncer._send_prompt = mock.AsyncMock(return_value=expected_message)
+                self.syncer._wait_for_confirmation = mock.AsyncMock(return_value=confirmed)
 
                 coro = self.syncer._get_confirmation_result(4, author)
                 actual_result, actual_message = await coro
diff --git a/tests/bot/cogs/sync/test_cog.py b/tests/bot/cogs/sync/test_cog.py
index 98c9afc0d..81398c61f 100644
--- a/tests/bot/cogs/sync/test_cog.py
+++ b/tests/bot/cogs/sync/test_cog.py
@@ -11,19 +11,7 @@ from tests import helpers
 from tests.base import CommandTestCase
 
 
-class MockSyncer(helpers.CustomMockMixin, mock.MagicMock):
-    """
-    A MagicMock subclass to mock Syncer objects.
-
-    Instances of this class will follow the specifications of `bot.cogs.sync.syncers.Syncer`
-    instances. For more information, see the `MockGuild` docstring.
-    """
-
-    def __init__(self, **kwargs) -> None:
-        super().__init__(spec_set=Syncer, **kwargs)
-
-
-class SyncExtensionTests(unittest.TestCase):
+class SyncExtensionTests(unittest.IsolatedAsyncioTestCase):
     """Tests for the sync extension."""
 
     @staticmethod
@@ -34,22 +22,21 @@ class SyncExtensionTests(unittest.TestCase):
         bot.add_cog.assert_called_once()
 
 
-class SyncCogTestCase(unittest.TestCase):
+class SyncCogTestCase(unittest.IsolatedAsyncioTestCase):
     """Base class for Sync cog tests. Sets up patches for syncers."""
 
     def setUp(self):
         self.bot = helpers.MockBot()
 
-        # These patch the type. When the type is called, a MockSyncer instanced is returned.
-        # MockSyncer is needed so that our custom AsyncMock is used.
-        # TODO: Use autospec instead in 3.8, which will automatically use AsyncMock when needed.
         self.role_syncer_patcher = mock.patch(
             "bot.cogs.sync.syncers.RoleSyncer",
-            new=mock.MagicMock(return_value=MockSyncer())
+            autospec=Syncer,
+            spec_set=True
         )
         self.user_syncer_patcher = mock.patch(
             "bot.cogs.sync.syncers.UserSyncer",
-            new=mock.MagicMock(return_value=MockSyncer())
+            autospec=Syncer,
+            spec_set=True
         )
         self.RoleSyncer = self.role_syncer_patcher.start()
         self.UserSyncer = self.user_syncer_patcher.start()
@@ -72,13 +59,13 @@ class SyncCogTestCase(unittest.TestCase):
 class SyncCogTests(SyncCogTestCase):
     """Tests for the Sync cog."""
 
-    @mock.patch.object(sync.Sync, "sync_guild")
+    @mock.patch.object(sync.Sync, "sync_guild", new_callable=mock.MagicMock)
     def test_sync_cog_init(self, sync_guild):
         """Should instantiate syncers and run a sync for the guild."""
         # Reset because a Sync cog was already instantiated in setUp.
         self.RoleSyncer.reset_mock()
         self.UserSyncer.reset_mock()
-        self.bot.loop.create_task.reset_mock()
+        self.bot.loop.create_task = mock.MagicMock()
 
         mock_sync_guild_coro = mock.MagicMock()
         sync_guild.return_value = mock_sync_guild_coro
@@ -90,7 +77,6 @@ class SyncCogTests(SyncCogTestCase):
         sync_guild.assert_called_once_with()
         self.bot.loop.create_task.assert_called_once_with(mock_sync_guild_coro)
 
-    @helpers.async_test
     async def test_sync_cog_sync_guild(self):
         """Roles and users should be synced only if a guild is successfully retrieved."""
         for guild in (helpers.MockGuild(), None):
@@ -126,14 +112,12 @@ class SyncCogTests(SyncCogTestCase):
             json=updated_information,
         )
 
-    @helpers.async_test
     async def test_sync_cog_patch_user(self):
         """A PATCH request should be sent and 404 errors ignored."""
         for side_effect in (None, self.response_error(404)):
             with self.subTest(side_effect=side_effect):
                 await self.patch_user_helper(side_effect)
 
-    @helpers.async_test
     async def test_sync_cog_patch_user_non_404(self):
         """A PATCH request should be sent and the error raised if it's not a 404."""
         with self.assertRaises(ResponseCodeError):
@@ -145,9 +129,8 @@ class SyncCogListenerTests(SyncCogTestCase):
 
     def setUp(self):
         super().setUp()
-        self.cog.patch_user = helpers.AsyncMock(spec_set=self.cog.patch_user)
+        self.cog.patch_user = mock.AsyncMock(spec_set=self.cog.patch_user)
 
-    @helpers.async_test
     async def test_sync_cog_on_guild_role_create(self):
         """A POST request should be sent with the new role's data."""
         self.assertTrue(self.cog.on_guild_role_create.__cog_listener__)
@@ -164,7 +147,6 @@ class SyncCogListenerTests(SyncCogTestCase):
 
         self.bot.api_client.post.assert_called_once_with("bot/roles", json=role_data)
 
-    @helpers.async_test
     async def test_sync_cog_on_guild_role_delete(self):
         """A DELETE request should be sent."""
         self.assertTrue(self.cog.on_guild_role_delete.__cog_listener__)
@@ -174,7 +156,6 @@ class SyncCogListenerTests(SyncCogTestCase):
 
         self.bot.api_client.delete.assert_called_once_with("bot/roles/99")
 
-    @helpers.async_test
     async def test_sync_cog_on_guild_role_update(self):
         """A PUT request should be sent if the colour, name, permissions, or position changes."""
         self.assertTrue(self.cog.on_guild_role_update.__cog_listener__)
@@ -212,7 +193,6 @@ class SyncCogListenerTests(SyncCogTestCase):
                     else:
                         self.bot.api_client.put.assert_not_called()
 
-    @helpers.async_test
     async def test_sync_cog_on_member_remove(self):
         """Member should patched to set in_guild as False."""
         self.assertTrue(self.cog.on_member_remove.__cog_listener__)
@@ -225,7 +205,6 @@ class SyncCogListenerTests(SyncCogTestCase):
             updated_information={"in_guild": False}
         )
 
-    @helpers.async_test
     async def test_sync_cog_on_member_update_roles(self):
         """Members should be patched if their roles have changed."""
         self.assertTrue(self.cog.on_member_update.__cog_listener__)
@@ -240,7 +219,6 @@ class SyncCogListenerTests(SyncCogTestCase):
         data = {"roles": sorted(role.id for role in after_member.roles)}
         self.cog.patch_user.assert_called_once_with(after_member.id, updated_information=data)
 
-    @helpers.async_test
     async def test_sync_cog_on_member_update_other(self):
         """Members should not be patched if other attributes have changed."""
         self.assertTrue(self.cog.on_member_update.__cog_listener__)
@@ -262,7 +240,6 @@ class SyncCogListenerTests(SyncCogTestCase):
 
                 self.cog.patch_user.assert_not_called()
 
-    @helpers.async_test
     async def test_sync_cog_on_user_update(self):
         """A user should be patched only if the name, discriminator, or avatar changes."""
         self.assertTrue(self.cog.on_user_update.__cog_listener__)
@@ -341,7 +318,6 @@ class SyncCogListenerTests(SyncCogTestCase):
 
         return data
 
-    @helpers.async_test
     async def test_sync_cog_on_member_join(self):
         """Should PUT user's data or POST it if the user doesn't exist."""
         for side_effect in (None, self.response_error(404)):
@@ -354,7 +330,6 @@ class SyncCogListenerTests(SyncCogTestCase):
                 else:
                     self.bot.api_client.post.assert_not_called()
 
-    @helpers.async_test
     async def test_sync_cog_on_member_join_non_404(self):
         """ResponseCodeError should be re-raised if status code isn't a 404."""
         with self.assertRaises(ResponseCodeError):
@@ -366,7 +341,6 @@ class SyncCogListenerTests(SyncCogTestCase):
 class SyncCogCommandTests(SyncCogTestCase, CommandTestCase):
     """Tests for the commands in the Sync cog."""
 
-    @helpers.async_test
     async def test_sync_roles_command(self):
         """sync() should be called on the RoleSyncer."""
         ctx = helpers.MockContext()
@@ -374,7 +348,6 @@ class SyncCogCommandTests(SyncCogTestCase, CommandTestCase):
 
         self.cog.role_syncer.sync.assert_called_once_with(ctx.guild, ctx)
 
-    @helpers.async_test
     async def test_sync_users_command(self):
         """sync() should be called on the UserSyncer."""
         ctx = helpers.MockContext()
@@ -382,7 +355,7 @@ class SyncCogCommandTests(SyncCogTestCase, CommandTestCase):
 
         self.cog.user_syncer.sync.assert_called_once_with(ctx.guild, ctx)
 
-    def test_commands_require_admin(self):
+    async def test_commands_require_admin(self):
         """The sync commands should only run if the author has the administrator permission."""
         cmds = (
             self.cog.sync_group,
@@ -392,4 +365,4 @@ class SyncCogCommandTests(SyncCogTestCase, CommandTestCase):
 
         for cmd in cmds:
             with self.subTest(cmd=cmd):
-                self.assertHasPermissionsCheck(cmd, {"administrator": True})
+                await self.assertHasPermissionsCheck(cmd, {"administrator": True})
diff --git a/tests/bot/cogs/sync/test_roles.py b/tests/bot/cogs/sync/test_roles.py
index 14fb2577a..79eee98f4 100644
--- a/tests/bot/cogs/sync/test_roles.py
+++ b/tests/bot/cogs/sync/test_roles.py
@@ -18,7 +18,7 @@ def fake_role(**kwargs):
     return kwargs
 
 
-class RoleSyncerDiffTests(unittest.TestCase):
+class RoleSyncerDiffTests(unittest.IsolatedAsyncioTestCase):
     """Tests for determining differences between roles in the DB and roles in the Guild cache."""
 
     def setUp(self):
@@ -39,7 +39,6 @@ class RoleSyncerDiffTests(unittest.TestCase):
 
         return guild
 
-    @helpers.async_test
     async def test_empty_diff_for_identical_roles(self):
         """No differences should be found if the roles in the guild and DB are identical."""
         self.bot.api_client.get.return_value = [fake_role()]
@@ -50,7 +49,6 @@ class RoleSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_diff_for_updated_roles(self):
         """Only updated roles should be added to the 'updated' set of the diff."""
         updated_role = fake_role(id=41, name="new")
@@ -63,7 +61,6 @@ class RoleSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_diff_for_new_roles(self):
         """Only new roles should be added to the 'created' set of the diff."""
         new_role = fake_role(id=41, name="new")
@@ -76,7 +73,6 @@ class RoleSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_diff_for_deleted_roles(self):
         """Only deleted roles should be added to the 'deleted' set of the diff."""
         deleted_role = fake_role(id=61, name="deleted")
@@ -89,7 +85,6 @@ class RoleSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_diff_for_new_updated_and_deleted_roles(self):
         """When roles are added, updated, and removed, all of them are returned properly."""
         new = fake_role(id=41, name="new")
@@ -109,14 +104,13 @@ class RoleSyncerDiffTests(unittest.TestCase):
         self.assertEqual(actual_diff, expected_diff)
 
 
-class RoleSyncerSyncTests(unittest.TestCase):
+class RoleSyncerSyncTests(unittest.IsolatedAsyncioTestCase):
     """Tests for the API requests that sync roles."""
 
     def setUp(self):
         self.bot = helpers.MockBot()
         self.syncer = RoleSyncer(self.bot)
 
-    @helpers.async_test
     async def test_sync_created_roles(self):
         """Only POST requests should be made with the correct payload."""
         roles = [fake_role(id=111), fake_role(id=222)]
@@ -132,7 +126,6 @@ class RoleSyncerSyncTests(unittest.TestCase):
         self.bot.api_client.put.assert_not_called()
         self.bot.api_client.delete.assert_not_called()
 
-    @helpers.async_test
     async def test_sync_updated_roles(self):
         """Only PUT requests should be made with the correct payload."""
         roles = [fake_role(id=111), fake_role(id=222)]
@@ -148,7 +141,6 @@ class RoleSyncerSyncTests(unittest.TestCase):
         self.bot.api_client.post.assert_not_called()
         self.bot.api_client.delete.assert_not_called()
 
-    @helpers.async_test
     async def test_sync_deleted_roles(self):
         """Only DELETE requests should be made with the correct payload."""
         roles = [fake_role(id=111), fake_role(id=222)]
diff --git a/tests/bot/cogs/sync/test_users.py b/tests/bot/cogs/sync/test_users.py
index 421bf6bb6..818883012 100644
--- a/tests/bot/cogs/sync/test_users.py
+++ b/tests/bot/cogs/sync/test_users.py
@@ -17,7 +17,7 @@ def fake_user(**kwargs):
     return kwargs
 
 
-class UserSyncerDiffTests(unittest.TestCase):
+class UserSyncerDiffTests(unittest.IsolatedAsyncioTestCase):
     """Tests for determining differences between users in the DB and users in the Guild cache."""
 
     def setUp(self):
@@ -42,7 +42,6 @@ class UserSyncerDiffTests(unittest.TestCase):
 
         return guild
 
-    @helpers.async_test
     async def test_empty_diff_for_no_users(self):
         """When no users are given, an empty diff should be returned."""
         guild = self.get_guild()
@@ -52,7 +51,6 @@ class UserSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_empty_diff_for_identical_users(self):
         """No differences should be found if the users in the guild and DB are identical."""
         self.bot.api_client.get.return_value = [fake_user()]
@@ -63,7 +61,6 @@ class UserSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_diff_for_updated_users(self):
         """Only updated users should be added to the 'updated' set of the diff."""
         updated_user = fake_user(id=99, name="new")
@@ -76,7 +73,6 @@ class UserSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_diff_for_new_users(self):
         """Only new users should be added to the 'created' set of the diff."""
         new_user = fake_user(id=99, name="new")
@@ -89,7 +85,6 @@ class UserSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_diff_sets_in_guild_false_for_leaving_users(self):
         """When a user leaves the guild, the `in_guild` flag is updated to `False`."""
         leaving_user = fake_user(id=63, in_guild=False)
@@ -102,7 +97,6 @@ class UserSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_diff_for_new_updated_and_leaving_users(self):
         """When users are added, updated, and removed, all of them are returned properly."""
         new_user = fake_user(id=99, name="new")
@@ -117,7 +111,6 @@ class UserSyncerDiffTests(unittest.TestCase):
 
         self.assertEqual(actual_diff, expected_diff)
 
-    @helpers.async_test
     async def test_empty_diff_for_db_users_not_in_guild(self):
         """When the DB knows a user the guild doesn't, no difference is found."""
         self.bot.api_client.get.return_value = [fake_user(), fake_user(id=63, in_guild=False)]
@@ -129,14 +122,13 @@ class UserSyncerDiffTests(unittest.TestCase):
         self.assertEqual(actual_diff, expected_diff)
 
 
-class UserSyncerSyncTests(unittest.TestCase):
+class UserSyncerSyncTests(unittest.IsolatedAsyncioTestCase):
     """Tests for the API requests that sync users."""
 
     def setUp(self):
         self.bot = helpers.MockBot()
         self.syncer = UserSyncer(self.bot)
 
-    @helpers.async_test
     async def test_sync_created_users(self):
         """Only POST requests should be made with the correct payload."""
         users = [fake_user(id=111), fake_user(id=222)]
@@ -152,7 +144,6 @@ class UserSyncerSyncTests(unittest.TestCase):
         self.bot.api_client.put.assert_not_called()
         self.bot.api_client.delete.assert_not_called()
 
-    @helpers.async_test
     async def test_sync_updated_users(self):
         """Only PUT requests should be made with the correct payload."""
         users = [fake_user(id=111), fake_user(id=222)]
diff --git a/tests/bot/cogs/test_duck_pond.py b/tests/bot/cogs/test_duck_pond.py
index 5b0a3b8c3..7e6bfc748 100644
--- a/tests/bot/cogs/test_duck_pond.py
+++ b/tests/bot/cogs/test_duck_pond.py
@@ -2,7 +2,7 @@ import asyncio
 import logging
 import typing
 import unittest
-from unittest.mock import MagicMock, patch
+from unittest.mock import AsyncMock, MagicMock, patch
 
 import discord
 
@@ -14,7 +14,7 @@ from tests import helpers
 MODULE_PATH = "bot.cogs.duck_pond"
 
 
-class DuckPondTests(base.LoggingTestCase):
+class DuckPondTests(base.LoggingTestsMixin, unittest.IsolatedAsyncioTestCase):
     """Tests for DuckPond functionality."""
 
     @classmethod
@@ -88,7 +88,6 @@ class DuckPondTests(base.LoggingTestCase):
             with self.subTest(user_type=user.name, expected_return=expected_return, actual_return=actual_return):
                 self.assertEqual(expected_return, actual_return)
 
-    @helpers.async_test
     async def test_has_green_checkmark_correctly_detects_presence_of_green_checkmark_emoji(self):
         """The `has_green_checkmark` method should only return `True` if one is present."""
         test_cases = (
@@ -172,7 +171,6 @@ class DuckPondTests(base.LoggingTestCase):
         nonstaffers = [helpers.MockMember() for _ in range(nonstaff)]
         return helpers.MockReaction(emoji=emoji, users=staffers + nonstaffers)
 
-    @helpers.async_test
     async def test_count_ducks_correctly_counts_the_number_of_eligible_duck_emojis(self):
         """The `count_ducks` method should return the number of unique staffers who gave a duck."""
         test_cases = (
@@ -280,7 +278,6 @@ class DuckPondTests(base.LoggingTestCase):
             with self.subTest(test_case=description, expected_count=expected_count, actual_count=actual_count):
                 self.assertEqual(expected_count, actual_count)
 
-    @helpers.async_test
     async def test_relay_message_correctly_relays_content_and_attachments(self):
         """The `relay_message` method should correctly relay message content and attachments."""
         send_webhook_path = f"{MODULE_PATH}.DuckPond.send_webhook"
@@ -296,8 +293,8 @@ class DuckPondTests(base.LoggingTestCase):
         )
 
         for message, expect_webhook_call, expect_attachment_call in test_values:
-            with patch(send_webhook_path, new_callable=helpers.AsyncMock) as send_webhook:
-                with patch(send_attachments_path, new_callable=helpers.AsyncMock) as send_attachments:
+            with patch(send_webhook_path, new_callable=AsyncMock) as send_webhook:
+                with patch(send_attachments_path, new_callable=AsyncMock) as send_attachments:
                     with self.subTest(clean_content=message.clean_content, attachments=message.attachments):
                         await self.cog.relay_message(message)
 
@@ -306,8 +303,7 @@ class DuckPondTests(base.LoggingTestCase):
 
                         message.add_reaction.assert_called_once_with(self.checkmark_emoji)
 
-    @patch(f"{MODULE_PATH}.send_attachments", new_callable=helpers.AsyncMock)
-    @helpers.async_test
+    @patch(f"{MODULE_PATH}.send_attachments", new_callable=AsyncMock)
     async def test_relay_message_handles_irretrievable_attachment_exceptions(self, send_attachments):
         """The `relay_message` method should handle irretrievable attachments."""
         message = helpers.MockMessage(clean_content="message", attachments=["attachment"])
@@ -316,18 +312,17 @@ class DuckPondTests(base.LoggingTestCase):
         self.cog.webhook = helpers.MockAsyncWebhook()
         log = logging.getLogger("bot.cogs.duck_pond")
 
-        for side_effect in side_effects:
+        for side_effect in side_effects:  # pragma: no cover
             send_attachments.side_effect = side_effect
-            with patch(f"{MODULE_PATH}.DuckPond.send_webhook", new_callable=helpers.AsyncMock) as send_webhook:
+            with patch(f"{MODULE_PATH}.DuckPond.send_webhook", new_callable=AsyncMock) as send_webhook:
                 with self.subTest(side_effect=type(side_effect).__name__):
                     with self.assertNotLogs(logger=log, level=logging.ERROR):
                         await self.cog.relay_message(message)
 
                     self.assertEqual(send_webhook.call_count, 2)
 
-    @patch(f"{MODULE_PATH}.DuckPond.send_webhook", new_callable=helpers.AsyncMock)
-    @patch(f"{MODULE_PATH}.send_attachments", new_callable=helpers.AsyncMock)
-    @helpers.async_test
+    @patch(f"{MODULE_PATH}.DuckPond.send_webhook", new_callable=AsyncMock)
+    @patch(f"{MODULE_PATH}.send_attachments", new_callable=AsyncMock)
     async def test_relay_message_handles_attachment_http_error(self, send_attachments, send_webhook):
         """The `relay_message` method should handle irretrievable attachments."""
         message = helpers.MockMessage(clean_content="message", attachments=["attachment"])
@@ -360,7 +355,6 @@ class DuckPondTests(base.LoggingTestCase):
         payload.emoji.name = emoji_name
         return payload
 
-    @helpers.async_test
     async def test_payload_has_duckpond_emoji_correctly_detects_relevant_emojis(self):
         """The `on_raw_reaction_add` event handler should ignore irrelevant emojis."""
         test_values = (
@@ -434,7 +428,6 @@ class DuckPondTests(base.LoggingTestCase):
 
         return channel, message, member, payload
 
-    @helpers.async_test
     async def test_on_raw_reaction_add_returns_for_bot_and_non_staff_members(self):
         """The `on_raw_reaction_add` event handler should return for bot users or non-staff members."""
         channel_id = 1234
@@ -463,7 +456,7 @@ class DuckPondTests(base.LoggingTestCase):
                 channel.fetch_message.reset_mock()
 
     @patch(f"{MODULE_PATH}.DuckPond.is_staff")
-    @patch(f"{MODULE_PATH}.DuckPond.count_ducks", new_callable=helpers.AsyncMock)
+    @patch(f"{MODULE_PATH}.DuckPond.count_ducks", new_callable=AsyncMock)
     def test_on_raw_reaction_add_returns_on_message_with_green_checkmark_placed_by_bot(self, count_ducks, is_staff):
         """The `on_raw_reaction_add` event should return when the message has a green check mark placed by the bot."""
         channel_id = 31415926535
@@ -485,7 +478,6 @@ class DuckPondTests(base.LoggingTestCase):
         # Assert that we've made it past `self.is_staff`
         is_staff.assert_called_once()
 
-    @helpers.async_test
     async def test_on_raw_reaction_add_does_not_relay_below_duck_threshold(self):
         """The `on_raw_reaction_add` listener should not relay messages or attachments below the duck threshold."""
         test_cases = (
@@ -499,8 +491,8 @@ class DuckPondTests(base.LoggingTestCase):
         payload.emoji = self.duck_pond_emoji
 
         for duck_count, should_relay in test_cases:
-            with patch(f"{MODULE_PATH}.DuckPond.relay_message", new_callable=helpers.AsyncMock) as relay_message:
-                with patch(f"{MODULE_PATH}.DuckPond.count_ducks", new_callable=helpers.AsyncMock) as count_ducks:
+            with patch(f"{MODULE_PATH}.DuckPond.relay_message", new_callable=AsyncMock) as relay_message:
+                with patch(f"{MODULE_PATH}.DuckPond.count_ducks", new_callable=AsyncMock) as count_ducks:
                     count_ducks.return_value = duck_count
                     with self.subTest(duck_count=duck_count, should_relay=should_relay):
                         await self.cog.on_raw_reaction_add(payload)
@@ -515,7 +507,6 @@ class DuckPondTests(base.LoggingTestCase):
                         if should_relay:
                             relay_message.assert_called_once_with(message)
 
-    @helpers.async_test
     async def test_on_raw_reaction_remove_prevents_removal_of_green_checkmark_depending_on_the_duck_count(self):
         """The `on_raw_reaction_remove` listener prevents removal of the check mark on messages with enough ducks."""
         checkmark = helpers.MockPartialEmoji(name=self.checkmark_emoji)
@@ -535,7 +526,7 @@ class DuckPondTests(base.LoggingTestCase):
             (constants.DuckPond.threshold + 1, True),
         )
         for duck_count, should_re_add_checkmark in test_cases:
-            with patch(f"{MODULE_PATH}.DuckPond.count_ducks", new_callable=helpers.AsyncMock) as count_ducks:
+            with patch(f"{MODULE_PATH}.DuckPond.count_ducks", new_callable=AsyncMock) as count_ducks:
                 count_ducks.return_value = duck_count
                 with self.subTest(duck_count=duck_count, should_re_add_checkmark=should_re_add_checkmark):
                     await self.cog.on_raw_reaction_remove(payload)
diff --git a/tests/bot/cogs/test_information.py b/tests/bot/cogs/test_information.py
index deae7ebad..5693d2946 100644
--- a/tests/bot/cogs/test_information.py
+++ b/tests/bot/cogs/test_information.py
@@ -19,7 +19,7 @@ class InformationCogTests(unittest.TestCase):
 
     @classmethod
     def setUpClass(cls):
-        cls.moderator_role = helpers.MockRole(name="Moderator", id=constants.Roles.moderator)
+        cls.moderator_role = helpers.MockRole(name="Moderator", id=constants.Roles.moderators)
 
     def setUp(self):
         """Sets up fresh objects for each test."""
@@ -34,7 +34,7 @@ class InformationCogTests(unittest.TestCase):
         """Test if the `role_info` command correctly returns the `moderator_role`."""
         self.ctx.guild.roles.append(self.moderator_role)
 
-        self.cog.roles_info.can_run = helpers.AsyncMock()
+        self.cog.roles_info.can_run = unittest.mock.AsyncMock()
         self.cog.roles_info.can_run.return_value = True
 
         coroutine = self.cog.roles_info.callback(self.cog, self.ctx)
@@ -72,7 +72,7 @@ class InformationCogTests(unittest.TestCase):
 
         self.ctx.guild.roles.append([dummy_role, admin_role])
 
-        self.cog.role_info.can_run = helpers.AsyncMock()
+        self.cog.role_info.can_run = unittest.mock.AsyncMock()
         self.cog.role_info.can_run.return_value = True
 
         coroutine = self.cog.role_info.callback(self.cog, self.ctx, dummy_role, admin_role)
@@ -174,7 +174,7 @@ class UserInfractionHelperMethodTests(unittest.TestCase):
     def setUp(self):
         """Common set-up steps done before for each test."""
         self.bot = helpers.MockBot()
-        self.bot.api_client.get = helpers.AsyncMock()
+        self.bot.api_client.get = unittest.mock.AsyncMock()
         self.cog = information.Information(self.bot)
         self.member = helpers.MockMember(id=1234)
 
@@ -345,10 +345,10 @@ class UserEmbedTests(unittest.TestCase):
     def setUp(self):
         """Common set-up steps done before for each test."""
         self.bot = helpers.MockBot()
-        self.bot.api_client.get = helpers.AsyncMock()
+        self.bot.api_client.get = unittest.mock.AsyncMock()
         self.cog = information.Information(self.bot)
 
-    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=helpers.AsyncMock(return_value=""))
+    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=unittest.mock.AsyncMock(return_value=""))
     def test_create_user_embed_uses_string_representation_of_user_in_title_if_nick_is_not_available(self):
         """The embed should use the string representation of the user if they don't have a nick."""
         ctx = helpers.MockContext(channel=helpers.MockTextChannel(id=1))
@@ -360,7 +360,7 @@ class UserEmbedTests(unittest.TestCase):
 
         self.assertEqual(embed.title, "Mr. Hemlock")
 
-    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=helpers.AsyncMock(return_value=""))
+    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=unittest.mock.AsyncMock(return_value=""))
     def test_create_user_embed_uses_nick_in_title_if_available(self):
         """The embed should use the nick if it's available."""
         ctx = helpers.MockContext(channel=helpers.MockTextChannel(id=1))
@@ -372,7 +372,7 @@ class UserEmbedTests(unittest.TestCase):
 
         self.assertEqual(embed.title, "Cat lover (Mr. Hemlock)")
 
-    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=helpers.AsyncMock(return_value=""))
+    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=unittest.mock.AsyncMock(return_value=""))
     def test_create_user_embed_ignores_everyone_role(self):
         """Created `!user` embeds should not contain mention of the @everyone-role."""
         ctx = helpers.MockContext(channel=helpers.MockTextChannel(id=1))
@@ -387,8 +387,8 @@ class UserEmbedTests(unittest.TestCase):
         self.assertIn("&Admins", embed.description)
         self.assertNotIn("&Everyone", embed.description)
 
-    @unittest.mock.patch(f"{COG_PATH}.expanded_user_infraction_counts", new_callable=helpers.AsyncMock)
-    @unittest.mock.patch(f"{COG_PATH}.user_nomination_counts", new_callable=helpers.AsyncMock)
+    @unittest.mock.patch(f"{COG_PATH}.expanded_user_infraction_counts", new_callable=unittest.mock.AsyncMock)
+    @unittest.mock.patch(f"{COG_PATH}.user_nomination_counts", new_callable=unittest.mock.AsyncMock)
     def test_create_user_embed_expanded_information_in_moderation_channels(self, nomination_counts, infraction_counts):
         """The embed should contain expanded infractions and nomination info in mod channels."""
         ctx = helpers.MockContext(channel=helpers.MockTextChannel(id=50))
@@ -423,7 +423,7 @@ class UserEmbedTests(unittest.TestCase):
             embed.description
         )
 
-    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new_callable=helpers.AsyncMock)
+    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new_callable=unittest.mock.AsyncMock)
     def test_create_user_embed_basic_information_outside_of_moderation_channels(self, infraction_counts):
         """The embed should contain only basic infraction data outside of mod channels."""
         ctx = helpers.MockContext(channel=helpers.MockTextChannel(id=100))
@@ -454,7 +454,7 @@ class UserEmbedTests(unittest.TestCase):
             embed.description
         )
 
-    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=helpers.AsyncMock(return_value=""))
+    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=unittest.mock.AsyncMock(return_value=""))
     def test_create_user_embed_uses_top_role_colour_when_user_has_roles(self):
         """The embed should be created with the colour of the top role, if a top role is available."""
         ctx = helpers.MockContext()
@@ -467,7 +467,7 @@ class UserEmbedTests(unittest.TestCase):
 
         self.assertEqual(embed.colour, discord.Colour(moderators_role.colour))
 
-    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=helpers.AsyncMock(return_value=""))
+    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=unittest.mock.AsyncMock(return_value=""))
     def test_create_user_embed_uses_blurple_colour_when_user_has_no_roles(self):
         """The embed should be created with a blurple colour if the user has no assigned roles."""
         ctx = helpers.MockContext()
@@ -477,7 +477,7 @@ class UserEmbedTests(unittest.TestCase):
 
         self.assertEqual(embed.colour, discord.Colour.blurple())
 
-    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=helpers.AsyncMock(return_value=""))
+    @unittest.mock.patch(f"{COG_PATH}.basic_user_infraction_counts", new=unittest.mock.AsyncMock(return_value=""))
     def test_create_user_embed_uses_png_format_of_user_avatar_as_thumbnail(self):
         """The embed thumbnail should be set to the user's avatar in `png` format."""
         ctx = helpers.MockContext()
@@ -521,7 +521,7 @@ class UserCommandTests(unittest.TestCase):
         """A regular user should not be able to use this command outside of bot-commands."""
         constants.MODERATION_ROLES = [self.moderator_role.id]
         constants.STAFF_ROLES = [self.moderator_role.id]
-        constants.Channels.bot = 50
+        constants.Channels.bot_commands = 50
 
         ctx = helpers.MockContext(author=self.author, channel=helpers.MockTextChannel(id=100))
 
@@ -529,11 +529,11 @@ class UserCommandTests(unittest.TestCase):
         with self.assertRaises(InChannelCheckFailure, msg=msg):
             asyncio.run(self.cog.user_info.callback(self.cog, ctx))
 
-    @unittest.mock.patch("bot.cogs.information.Information.create_user_embed", new_callable=helpers.AsyncMock)
+    @unittest.mock.patch("bot.cogs.information.Information.create_user_embed", new_callable=unittest.mock.AsyncMock)
     def test_regular_user_may_use_command_in_bot_commands_channel(self, create_embed, constants):
         """A regular user should be allowed to use `!user` targeting themselves in bot-commands."""
         constants.STAFF_ROLES = [self.moderator_role.id]
-        constants.Channels.bot = 50
+        constants.Channels.bot_commands = 50
 
         ctx = helpers.MockContext(author=self.author, channel=helpers.MockTextChannel(id=50))
 
@@ -542,11 +542,11 @@ class UserCommandTests(unittest.TestCase):
         create_embed.assert_called_once_with(ctx, self.author)
         ctx.send.assert_called_once()
 
-    @unittest.mock.patch("bot.cogs.information.Information.create_user_embed", new_callable=helpers.AsyncMock)
+    @unittest.mock.patch("bot.cogs.information.Information.create_user_embed", new_callable=unittest.mock.AsyncMock)
     def test_regular_user_can_explicitly_target_themselves(self, create_embed, constants):
         """A user should target itself with `!user` when a `user` argument was not provided."""
         constants.STAFF_ROLES = [self.moderator_role.id]
-        constants.Channels.bot = 50
+        constants.Channels.bot_commands = 50
 
         ctx = helpers.MockContext(author=self.author, channel=helpers.MockTextChannel(id=50))
 
@@ -555,11 +555,11 @@ class UserCommandTests(unittest.TestCase):
         create_embed.assert_called_once_with(ctx, self.author)
         ctx.send.assert_called_once()
 
-    @unittest.mock.patch("bot.cogs.information.Information.create_user_embed", new_callable=helpers.AsyncMock)
+    @unittest.mock.patch("bot.cogs.information.Information.create_user_embed", new_callable=unittest.mock.AsyncMock)
     def test_staff_members_can_bypass_channel_restriction(self, create_embed, constants):
         """Staff members should be able to bypass the bot-commands channel restriction."""
         constants.STAFF_ROLES = [self.moderator_role.id]
-        constants.Channels.bot = 50
+        constants.Channels.bot_commands = 50
 
         ctx = helpers.MockContext(author=self.moderator, channel=helpers.MockTextChannel(id=200))
 
@@ -568,7 +568,7 @@ class UserCommandTests(unittest.TestCase):
         create_embed.assert_called_once_with(ctx, self.moderator)
         ctx.send.assert_called_once()
 
-    @unittest.mock.patch("bot.cogs.information.Information.create_user_embed", new_callable=helpers.AsyncMock)
+    @unittest.mock.patch("bot.cogs.information.Information.create_user_embed", new_callable=unittest.mock.AsyncMock)
     def test_moderators_can_target_another_member(self, create_embed, constants):
         """A moderator should be able to use `!user` targeting another user."""
         constants.MODERATION_ROLES = [self.moderator_role.id]
diff --git a/tests/bot/cogs/test_snekbox.py b/tests/bot/cogs/test_snekbox.py
new file mode 100644
index 000000000..9cd7f0154
--- /dev/null
+++ b/tests/bot/cogs/test_snekbox.py
@@ -0,0 +1,354 @@
+import asyncio
+import logging
+import unittest
+from unittest.mock import AsyncMock, MagicMock, Mock, call, patch
+
+from bot.cogs import snekbox
+from bot.cogs.snekbox import Snekbox
+from bot.constants import URLs
+from tests.helpers import MockBot, MockContext, MockMessage, MockReaction, MockUser
+
+
+class SnekboxTests(unittest.IsolatedAsyncioTestCase):
+    def setUp(self):
+        """Add mocked bot and cog to the instance."""
+        self.bot = MockBot()
+        self.cog = Snekbox(bot=self.bot)
+
+    async def test_post_eval(self):
+        """Post the eval code to the URLs.snekbox_eval_api endpoint."""
+        resp = MagicMock()
+        resp.json = AsyncMock(return_value="return")
+        self.bot.http_session.post().__aenter__.return_value = resp
+
+        self.assertEqual(await self.cog.post_eval("import random"), "return")
+        self.bot.http_session.post.assert_called_with(
+            URLs.snekbox_eval_api,
+            json={"input": "import random"},
+            raise_for_status=True
+        )
+        resp.json.assert_awaited_once()
+
+    async def test_upload_output_reject_too_long(self):
+        """Reject output longer than MAX_PASTE_LEN."""
+        result = await self.cog.upload_output("-" * (snekbox.MAX_PASTE_LEN + 1))
+        self.assertEqual(result, "too long to upload")
+
+    async def test_upload_output(self):
+        """Upload the eval output to the URLs.paste_service.format(key="documents") endpoint."""
+        key = "MarkDiamond"
+        resp = MagicMock()
+        resp.json = AsyncMock(return_value={"key": key})
+        self.bot.http_session.post().__aenter__.return_value = resp
+
+        self.assertEqual(
+            await self.cog.upload_output("My awesome output"),
+            URLs.paste_service.format(key=key)
+        )
+        self.bot.http_session.post.assert_called_with(
+            URLs.paste_service.format(key="documents"),
+            data="My awesome output",
+            raise_for_status=True
+        )
+
+    async def test_upload_output_gracefully_fallback_if_exception_during_request(self):
+        """Output upload gracefully fallback if the upload fail."""
+        resp = MagicMock()
+        resp.json = AsyncMock(side_effect=Exception)
+        self.bot.http_session.post().__aenter__.return_value = resp
+
+        log = logging.getLogger("bot.cogs.snekbox")
+        with self.assertLogs(logger=log, level='ERROR'):
+            await self.cog.upload_output('My awesome output!')
+
+    async def test_upload_output_gracefully_fallback_if_no_key_in_response(self):
+        """Output upload gracefully fallback if there is no key entry in the response body."""
+        self.assertEqual((await self.cog.upload_output('My awesome output!')), None)
+
+    def test_prepare_input(self):
+        cases = (
+            ('print("Hello world!")', 'print("Hello world!")', 'non-formatted'),
+            ('`print("Hello world!")`', 'print("Hello world!")', 'one line code block'),
+            ('```\nprint("Hello world!")```', 'print("Hello world!")', 'multiline code block'),
+            ('```py\nprint("Hello world!")```', 'print("Hello world!")', 'multiline python code block'),
+        )
+        for case, expected, testname in cases:
+            with self.subTest(msg=f'Extract code from {testname}.'):
+                self.assertEqual(self.cog.prepare_input(case), expected)
+
+    def test_get_results_message(self):
+        """Return error and message according to the eval result."""
+        cases = (
+            ('ERROR', None, ('Your eval job has failed', 'ERROR')),
+            ('', 128 + snekbox.SIGKILL, ('Your eval job timed out or ran out of memory', '')),
+            ('', 255, ('Your eval job has failed', 'A fatal NsJail error occurred'))
+        )
+        for stdout, returncode, expected in cases:
+            with self.subTest(stdout=stdout, returncode=returncode, expected=expected):
+                actual = self.cog.get_results_message({'stdout': stdout, 'returncode': returncode})
+                self.assertEqual(actual, expected)
+
+    @patch('bot.cogs.snekbox.Signals', side_effect=ValueError)
+    def test_get_results_message_invalid_signal(self, mock_Signals: Mock):
+        self.assertEqual(
+            self.cog.get_results_message({'stdout': '', 'returncode': 127}),
+            ('Your eval job has completed with return code 127', '')
+        )
+
+    @patch('bot.cogs.snekbox.Signals')
+    def test_get_results_message_valid_signal(self, mock_Signals: Mock):
+        mock_Signals.return_value.name = 'SIGTEST'
+        self.assertEqual(
+            self.cog.get_results_message({'stdout': '', 'returncode': 127}),
+            ('Your eval job has completed with return code 127 (SIGTEST)', '')
+        )
+
+    def test_get_status_emoji(self):
+        """Return emoji according to the eval result."""
+        cases = (
+            (' ', -1, ':warning:'),
+            ('Hello world!', 0, ':white_check_mark:'),
+            ('Invalid beard size', -1, ':x:')
+        )
+        for stdout, returncode, expected in cases:
+            with self.subTest(stdout=stdout, returncode=returncode, expected=expected):
+                actual = self.cog.get_status_emoji({'stdout': stdout, 'returncode': returncode})
+                self.assertEqual(actual, expected)
+
+    async def test_format_output(self):
+        """Test output formatting."""
+        self.cog.upload_output = AsyncMock(return_value='https://testificate.com/')
+
+        too_many_lines = (
+            '001 | v\n002 | e\n003 | r\n004 | y\n005 | l\n006 | o\n'
+            '007 | n\n008 | g\n009 | b\n010 | e\n011 | a\n... (truncated - too many lines)'
+        )
+        too_long_too_many_lines = (
+            "\n".join(
+                f"{i:03d} | {line}" for i, line in enumerate(['verylongbeard' * 10] * 15, 1)
+            )[:1000] + "\n... (truncated - too long, too many lines)"
+        )
+
+        cases = (
+            ('', ('[No output]', None), 'No output'),
+            ('My awesome output', ('My awesome output', None), 'One line output'),
+            ('<@', ("<@\u200B", None), r'Convert <@ to <@\u200B'),
+            ('<!@', ("<!@\u200B", None), r'Convert <!@ to <!@\u200B'),
+            (
+                '\u202E\u202E\u202E',
+                ('Code block escape attempt detected; will not output result', None),
+                'Detect RIGHT-TO-LEFT OVERRIDE'
+            ),
+            (
+                '\u200B\u200B\u200B',
+                ('Code block escape attempt detected; will not output result', None),
+                'Detect ZERO WIDTH SPACE'
+            ),
+            ('long\nbeard', ('001 | long\n002 | beard', None), 'Two line output'),
+            (
+                'v\ne\nr\ny\nl\no\nn\ng\nb\ne\na\nr\nd',
+                (too_many_lines, 'https://testificate.com/'),
+                '12 lines output'
+            ),
+            (
+                'verylongbeard' * 100,
+                ('verylongbeard' * 76 + 'verylongbear\n... (truncated - too long)', 'https://testificate.com/'),
+                '1300 characters output'
+            ),
+            (
+                ('verylongbeard' * 10 + '\n') * 15,
+                (too_long_too_many_lines, 'https://testificate.com/'),
+                '15 lines, 1965 characters output'
+            ),
+        )
+        for case, expected, testname in cases:
+            with self.subTest(msg=testname, case=case, expected=expected):
+                self.assertEqual(await self.cog.format_output(case), expected)
+
+    async def test_eval_command_evaluate_once(self):
+        """Test the eval command procedure."""
+        ctx = MockContext()
+        response = MockMessage()
+        self.cog.prepare_input = MagicMock(return_value='MyAwesomeFormattedCode')
+        self.cog.send_eval = AsyncMock(return_value=response)
+        self.cog.continue_eval = AsyncMock(return_value=None)
+
+        await self.cog.eval_command.callback(self.cog, ctx=ctx, code='MyAwesomeCode')
+        self.cog.prepare_input.assert_called_once_with('MyAwesomeCode')
+        self.cog.send_eval.assert_called_once_with(ctx, 'MyAwesomeFormattedCode')
+        self.cog.continue_eval.assert_called_once_with(ctx, response)
+
+    async def test_eval_command_evaluate_twice(self):
+        """Test the eval and re-eval command procedure."""
+        ctx = MockContext()
+        response = MockMessage()
+        self.cog.prepare_input = MagicMock(return_value='MyAwesomeFormattedCode')
+        self.cog.send_eval = AsyncMock(return_value=response)
+        self.cog.continue_eval = AsyncMock()
+        self.cog.continue_eval.side_effect = ('MyAwesomeCode-2', None)
+
+        await self.cog.eval_command.callback(self.cog, ctx=ctx, code='MyAwesomeCode')
+        self.cog.prepare_input.has_calls(call('MyAwesomeCode'), call('MyAwesomeCode-2'))
+        self.cog.send_eval.assert_called_with(ctx, 'MyAwesomeFormattedCode')
+        self.cog.continue_eval.assert_called_with(ctx, response)
+
+    async def test_eval_command_reject_two_eval_at_the_same_time(self):
+        """Test if the eval command rejects an eval if the author already have a running eval."""
+        ctx = MockContext()
+        ctx.author.id = 42
+        ctx.author.mention = '@LemonLemonishBeard#0042'
+        ctx.send = AsyncMock()
+        self.cog.jobs = (42,)
+        await self.cog.eval_command.callback(self.cog, ctx=ctx, code='MyAwesomeCode')
+        ctx.send.assert_called_once_with(
+            "@LemonLemonishBeard#0042 You've already got a job running - please wait for it to finish!"
+        )
+
+    async def test_eval_command_call_help(self):
+        """Test if the eval command call the help command if no code is provided."""
+        ctx = MockContext()
+        ctx.invoke = AsyncMock()
+        await self.cog.eval_command.callback(self.cog, ctx=ctx, code='')
+        ctx.invoke.assert_called_once_with(self.bot.get_command("help"), "eval")
+
+    async def test_send_eval(self):
+        """Test the send_eval function."""
+        ctx = MockContext()
+        ctx.message = MockMessage()
+        ctx.send = AsyncMock()
+        ctx.author.mention = '@LemonLemonishBeard#0042'
+
+        self.cog.post_eval = AsyncMock(return_value={'stdout': '', 'returncode': 0})
+        self.cog.get_results_message = MagicMock(return_value=('Return code 0', ''))
+        self.cog.get_status_emoji = MagicMock(return_value=':yay!:')
+        self.cog.format_output = AsyncMock(return_value=('[No output]', None))
+
+        await self.cog.send_eval(ctx, 'MyAwesomeCode')
+        ctx.send.assert_called_once_with(
+            '@LemonLemonishBeard#0042 :yay!: Return code 0.\n\n```py\n[No output]\n```'
+        )
+        self.cog.post_eval.assert_called_once_with('MyAwesomeCode')
+        self.cog.get_status_emoji.assert_called_once_with({'stdout': '', 'returncode': 0})
+        self.cog.get_results_message.assert_called_once_with({'stdout': '', 'returncode': 0})
+        self.cog.format_output.assert_called_once_with('')
+
+    async def test_send_eval_with_paste_link(self):
+        """Test the send_eval function with a too long output that generate a paste link."""
+        ctx = MockContext()
+        ctx.message = MockMessage()
+        ctx.send = AsyncMock()
+        ctx.author.mention = '@LemonLemonishBeard#0042'
+
+        self.cog.post_eval = AsyncMock(return_value={'stdout': 'Way too long beard', 'returncode': 0})
+        self.cog.get_results_message = MagicMock(return_value=('Return code 0', ''))
+        self.cog.get_status_emoji = MagicMock(return_value=':yay!:')
+        self.cog.format_output = AsyncMock(return_value=('Way too long beard', 'lookatmybeard.com'))
+
+        await self.cog.send_eval(ctx, 'MyAwesomeCode')
+        ctx.send.assert_called_once_with(
+            '@LemonLemonishBeard#0042 :yay!: Return code 0.'
+            '\n\n```py\nWay too long beard\n```\nFull output: lookatmybeard.com'
+        )
+        self.cog.post_eval.assert_called_once_with('MyAwesomeCode')
+        self.cog.get_status_emoji.assert_called_once_with({'stdout': 'Way too long beard', 'returncode': 0})
+        self.cog.get_results_message.assert_called_once_with({'stdout': 'Way too long beard', 'returncode': 0})
+        self.cog.format_output.assert_called_once_with('Way too long beard')
+
+    async def test_send_eval_with_non_zero_eval(self):
+        """Test the send_eval function with a code returning a non-zero code."""
+        ctx = MockContext()
+        ctx.message = MockMessage()
+        ctx.send = AsyncMock()
+        ctx.author.mention = '@LemonLemonishBeard#0042'
+        self.cog.post_eval = AsyncMock(return_value={'stdout': 'ERROR', 'returncode': 127})
+        self.cog.get_results_message = MagicMock(return_value=('Return code 127', 'Beard got stuck in the eval'))
+        self.cog.get_status_emoji = MagicMock(return_value=':nope!:')
+        self.cog.format_output = AsyncMock()  # This function isn't called
+
+        await self.cog.send_eval(ctx, 'MyAwesomeCode')
+        ctx.send.assert_called_once_with(
+            '@LemonLemonishBeard#0042 :nope!: Return code 127.\n\n```py\nBeard got stuck in the eval\n```'
+        )
+        self.cog.post_eval.assert_called_once_with('MyAwesomeCode')
+        self.cog.get_status_emoji.assert_called_once_with({'stdout': 'ERROR', 'returncode': 127})
+        self.cog.get_results_message.assert_called_once_with({'stdout': 'ERROR', 'returncode': 127})
+        self.cog.format_output.assert_not_called()
+
+    @patch("bot.cogs.snekbox.partial")
+    async def test_continue_eval_does_continue(self, partial_mock):
+        """Test that the continue_eval function does continue if required conditions are met."""
+        ctx = MockContext(message=MockMessage(add_reaction=AsyncMock(), clear_reactions=AsyncMock()))
+        response = MockMessage(delete=AsyncMock())
+        new_msg = MockMessage(content='!e NewCode')
+        self.bot.wait_for.side_effect = ((None, new_msg), None)
+
+        actual = await self.cog.continue_eval(ctx, response)
+        self.assertEqual(actual, 'NewCode')
+        self.bot.wait_for.assert_has_awaits(
+            (
+                call('message_edit', check=partial_mock(snekbox.predicate_eval_message_edit, ctx), timeout=10),
+                call('reaction_add', check=partial_mock(snekbox.predicate_eval_emoji_reaction, ctx), timeout=10)
+            )
+        )
+        ctx.message.add_reaction.assert_called_once_with(snekbox.REEVAL_EMOJI)
+        ctx.message.clear_reactions.assert_called_once()
+        response.delete.assert_called_once()
+
+    async def test_continue_eval_does_not_continue(self):
+        ctx = MockContext(message=MockMessage(clear_reactions=AsyncMock()))
+        self.bot.wait_for.side_effect = asyncio.TimeoutError
+
+        actual = await self.cog.continue_eval(ctx, MockMessage())
+        self.assertEqual(actual, None)
+        ctx.message.clear_reactions.assert_called_once()
+
+    def test_predicate_eval_message_edit(self):
+        """Test the predicate_eval_message_edit function."""
+        msg0 = MockMessage(id=1, content='abc')
+        msg1 = MockMessage(id=2, content='abcdef')
+        msg2 = MockMessage(id=1, content='abcdef')
+
+        cases = (
+            (msg0, msg0, False, 'same ID, same content'),
+            (msg0, msg1, False, 'different ID, different content'),
+            (msg0, msg2, True, 'same ID, different content')
+        )
+        for ctx_msg, new_msg, expected, testname in cases:
+            with self.subTest(msg=f'Messages with {testname} return {expected}'):
+                ctx = MockContext(message=ctx_msg)
+                actual = snekbox.predicate_eval_message_edit(ctx, ctx_msg, new_msg)
+                self.assertEqual(actual, expected)
+
+    def test_predicate_eval_emoji_reaction(self):
+        """Test the predicate_eval_emoji_reaction function."""
+        valid_reaction = MockReaction(message=MockMessage(id=1))
+        valid_reaction.__str__.return_value = snekbox.REEVAL_EMOJI
+        valid_ctx = MockContext(message=MockMessage(id=1), author=MockUser(id=2))
+        valid_user = MockUser(id=2)
+
+        invalid_reaction_id = MockReaction(message=MockMessage(id=42))
+        invalid_reaction_id.__str__.return_value = snekbox.REEVAL_EMOJI
+        invalid_user_id = MockUser(id=42)
+        invalid_reaction_str = MockReaction(message=MockMessage(id=1))
+        invalid_reaction_str.__str__.return_value = ':longbeard:'
+
+        cases = (
+            (invalid_reaction_id, valid_user, False, 'invalid reaction ID'),
+            (valid_reaction, invalid_user_id, False, 'invalid user ID'),
+            (invalid_reaction_str, valid_user, False, 'invalid reaction __str__'),
+            (valid_reaction, valid_user, True, 'matching attributes')
+        )
+        for reaction, user, expected, testname in cases:
+            with self.subTest(msg=f'Test with {testname} and expected return {expected}'):
+                actual = snekbox.predicate_eval_emoji_reaction(valid_ctx, reaction, user)
+                self.assertEqual(actual, expected)
+
+
+class SnekboxSetupTests(unittest.TestCase):
+    """Tests setup of the `Snekbox` cog."""
+
+    def test_setup(self):
+        """Setup of the extension should call add_cog."""
+        bot = MockBot()
+        snekbox.setup(bot)
+        bot.add_cog.assert_called_once()
diff --git a/tests/bot/cogs/test_token_remover.py b/tests/bot/cogs/test_token_remover.py
index a54b839d7..33d1ec170 100644
--- a/tests/bot/cogs/test_token_remover.py
+++ b/tests/bot/cogs/test_token_remover.py
@@ -1,7 +1,7 @@
 import asyncio
 import logging
 import unittest
-from unittest.mock import MagicMock
+from unittest.mock import AsyncMock, MagicMock
 
 from discord import Colour
 
@@ -11,7 +11,7 @@ from bot.cogs.token_remover import (
     setup as setup_cog,
 )
 from bot.constants import Channels, Colours, Event, Icons
-from tests.helpers import AsyncMock, MockBot, MockMessage
+from tests.helpers import MockBot, MockMessage
 
 
 class TokenRemoverTests(unittest.TestCase):
diff --git a/tests/bot/rules/__init__.py b/tests/bot/rules/__init__.py
index 36c986fe1..0d570f5a3 100644
--- a/tests/bot/rules/__init__.py
+++ b/tests/bot/rules/__init__.py
@@ -12,7 +12,7 @@ class DisallowedCase(NamedTuple):
     n_violations: int
 
 
-class RuleTest(unittest.TestCase, metaclass=ABCMeta):
+class RuleTest(unittest.IsolatedAsyncioTestCase, metaclass=ABCMeta):
     """
     Abstract class for antispam rule test cases.
 
@@ -68,9 +68,9 @@ class RuleTest(unittest.TestCase, metaclass=ABCMeta):
     @abstractmethod
     def relevant_messages(self, case: DisallowedCase) -> Iterable[MockMessage]:
         """Give expected relevant messages for `case`."""
-        raise NotImplementedError
+        raise NotImplementedError  # pragma: no cover
 
     @abstractmethod
     def get_report(self, case: DisallowedCase) -> str:
         """Give expected error report for `case`."""
-        raise NotImplementedError
+        raise NotImplementedError  # pragma: no cover
diff --git a/tests/bot/rules/test_attachments.py b/tests/bot/rules/test_attachments.py
index e54b4b5b8..d7e779221 100644
--- a/tests/bot/rules/test_attachments.py
+++ b/tests/bot/rules/test_attachments.py
@@ -2,7 +2,7 @@ from typing import Iterable
 
 from bot.rules import attachments
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 
 def make_msg(author: str, total_attachments: int) -> MockMessage:
@@ -17,7 +17,6 @@ class AttachmentRuleTests(RuleTest):
         self.apply = attachments.apply
         self.config = {"max": 5, "interval": 10}
 
-    @async_test
     async def test_allows_messages_without_too_many_attachments(self):
         """Messages without too many attachments are allowed as-is."""
         cases = (
@@ -28,7 +27,6 @@ class AttachmentRuleTests(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_disallows_messages_with_too_many_attachments(self):
         """Messages with too many attachments trigger the rule."""
         cases = (
diff --git a/tests/bot/rules/test_burst.py b/tests/bot/rules/test_burst.py
index 72f0be0c7..03682966b 100644
--- a/tests/bot/rules/test_burst.py
+++ b/tests/bot/rules/test_burst.py
@@ -2,7 +2,7 @@ from typing import Iterable
 
 from bot.rules import burst
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 
 def make_msg(author: str) -> MockMessage:
@@ -21,7 +21,6 @@ class BurstRuleTests(RuleTest):
         self.apply = burst.apply
         self.config = {"max": 2, "interval": 10}
 
-    @async_test
     async def test_allows_messages_within_limit(self):
         """Cases which do not violate the rule."""
         cases = (
@@ -31,7 +30,6 @@ class BurstRuleTests(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_disallows_messages_beyond_limit(self):
         """Cases where the amount of messages exceeds the limit, triggering the rule."""
         cases = (
diff --git a/tests/bot/rules/test_burst_shared.py b/tests/bot/rules/test_burst_shared.py
index 47367a5f8..3275143d5 100644
--- a/tests/bot/rules/test_burst_shared.py
+++ b/tests/bot/rules/test_burst_shared.py
@@ -2,7 +2,7 @@ from typing import Iterable
 
 from bot.rules import burst_shared
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 
 def make_msg(author: str) -> MockMessage:
@@ -21,7 +21,6 @@ class BurstSharedRuleTests(RuleTest):
         self.apply = burst_shared.apply
         self.config = {"max": 2, "interval": 10}
 
-    @async_test
     async def test_allows_messages_within_limit(self):
         """
         Cases that do not violate the rule.
@@ -34,7 +33,6 @@ class BurstSharedRuleTests(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_disallows_messages_beyond_limit(self):
         """Cases where the amount of messages exceeds the limit, triggering the rule."""
         cases = (
diff --git a/tests/bot/rules/test_chars.py b/tests/bot/rules/test_chars.py
index 7cc36f49e..f1e3c76a7 100644
--- a/tests/bot/rules/test_chars.py
+++ b/tests/bot/rules/test_chars.py
@@ -2,7 +2,7 @@ from typing import Iterable
 
 from bot.rules import chars
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 
 def make_msg(author: str, n_chars: int) -> MockMessage:
@@ -20,7 +20,6 @@ class CharsRuleTests(RuleTest):
             "interval": 10,
         }
 
-    @async_test
     async def test_allows_messages_within_limit(self):
         """Cases with a total amount of chars within limit."""
         cases = (
@@ -31,7 +30,6 @@ class CharsRuleTests(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_disallows_messages_beyond_limit(self):
         """Cases where the total amount of chars exceeds the limit, triggering the rule."""
         cases = (
diff --git a/tests/bot/rules/test_discord_emojis.py b/tests/bot/rules/test_discord_emojis.py
index 0239b0b00..9a72723e2 100644
--- a/tests/bot/rules/test_discord_emojis.py
+++ b/tests/bot/rules/test_discord_emojis.py
@@ -2,7 +2,7 @@ from typing import Iterable
 
 from bot.rules import discord_emojis
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 discord_emoji = "<:abcd:1234>"  # Discord emojis follow the format <:name:id>
 
@@ -19,7 +19,6 @@ class DiscordEmojisRuleTests(RuleTest):
         self.apply = discord_emojis.apply
         self.config = {"max": 2, "interval": 10}
 
-    @async_test
     async def test_allows_messages_within_limit(self):
         """Cases with a total amount of discord emojis within limit."""
         cases = (
@@ -29,7 +28,6 @@ class DiscordEmojisRuleTests(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_disallows_messages_beyond_limit(self):
         """Cases with more than the allowed amount of discord emojis."""
         cases = (
diff --git a/tests/bot/rules/test_duplicates.py b/tests/bot/rules/test_duplicates.py
index 59e0fb6ef..9bd886a77 100644
--- a/tests/bot/rules/test_duplicates.py
+++ b/tests/bot/rules/test_duplicates.py
@@ -2,7 +2,7 @@ from typing import Iterable
 
 from bot.rules import duplicates
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 
 def make_msg(author: str, content: str) -> MockMessage:
@@ -17,7 +17,6 @@ class DuplicatesRuleTests(RuleTest):
         self.apply = duplicates.apply
         self.config = {"max": 2, "interval": 10}
 
-    @async_test
     async def test_allows_messages_within_limit(self):
         """Cases which do not violate the rule."""
         cases = (
@@ -28,7 +27,6 @@ class DuplicatesRuleTests(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_disallows_messages_beyond_limit(self):
         """Cases with too many duplicate messages from the same author."""
         cases = (
diff --git a/tests/bot/rules/test_links.py b/tests/bot/rules/test_links.py
index 3c3f90e5f..b091bd9d7 100644
--- a/tests/bot/rules/test_links.py
+++ b/tests/bot/rules/test_links.py
@@ -2,7 +2,7 @@ from typing import Iterable
 
 from bot.rules import links
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 
 def make_msg(author: str, total_links: int) -> MockMessage:
@@ -21,7 +21,6 @@ class LinksTests(RuleTest):
             "interval": 10
         }
 
-    @async_test
     async def test_links_within_limit(self):
         """Messages with an allowed amount of links."""
         cases = (
@@ -34,7 +33,6 @@ class LinksTests(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_links_exceeding_limit(self):
         """Messages with a a higher than allowed amount of links."""
         cases = (
diff --git a/tests/bot/rules/test_mentions.py b/tests/bot/rules/test_mentions.py
index ebcdabac6..6444532f2 100644
--- a/tests/bot/rules/test_mentions.py
+++ b/tests/bot/rules/test_mentions.py
@@ -2,7 +2,7 @@ from typing import Iterable
 
 from bot.rules import mentions
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 
 def make_msg(author: str, total_mentions: int) -> MockMessage:
@@ -20,7 +20,6 @@ class TestMentions(RuleTest):
             "interval": 10,
         }
 
-    @async_test
     async def test_mentions_within_limit(self):
         """Messages with an allowed amount of mentions."""
         cases = (
@@ -32,7 +31,6 @@ class TestMentions(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_mentions_exceeding_limit(self):
         """Messages with a higher than allowed amount of mentions."""
         cases = (
diff --git a/tests/bot/rules/test_newlines.py b/tests/bot/rules/test_newlines.py
index d61c4609d..e35377773 100644
--- a/tests/bot/rules/test_newlines.py
+++ b/tests/bot/rules/test_newlines.py
@@ -2,7 +2,7 @@ from typing import Iterable, List
 
 from bot.rules import newlines
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 
 def make_msg(author: str, newline_groups: List[int]) -> MockMessage:
@@ -29,7 +29,6 @@ class TotalNewlinesRuleTests(RuleTest):
             "interval": 10,
         }
 
-    @async_test
     async def test_allows_messages_within_limit(self):
         """Cases which do not violate the rule."""
         cases = (
@@ -41,7 +40,6 @@ class TotalNewlinesRuleTests(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_disallows_messages_total(self):
         """Cases which violate the rule by having too many newlines in total."""
         cases = (
@@ -79,7 +77,6 @@ class GroupNewlinesRuleTests(RuleTest):
         self.apply = newlines.apply
         self.config = {"max": 5, "max_consecutive": 3, "interval": 10}
 
-    @async_test
     async def test_disallows_messages_consecutive(self):
         """Cases which violate the rule due to having too many consecutive newlines."""
         cases = (
diff --git a/tests/bot/rules/test_role_mentions.py b/tests/bot/rules/test_role_mentions.py
index b339cccf7..26c05d527 100644
--- a/tests/bot/rules/test_role_mentions.py
+++ b/tests/bot/rules/test_role_mentions.py
@@ -2,7 +2,7 @@ from typing import Iterable
 
 from bot.rules import role_mentions
 from tests.bot.rules import DisallowedCase, RuleTest
-from tests.helpers import MockMessage, async_test
+from tests.helpers import MockMessage
 
 
 def make_msg(author: str, n_mentions: int) -> MockMessage:
@@ -17,7 +17,6 @@ class RoleMentionsRuleTests(RuleTest):
         self.apply = role_mentions.apply
         self.config = {"max": 2, "interval": 10}
 
-    @async_test
     async def test_allows_messages_within_limit(self):
         """Cases with a total amount of role mentions within limit."""
         cases = (
@@ -27,7 +26,6 @@ class RoleMentionsRuleTests(RuleTest):
 
         await self.run_allowed(cases)
 
-    @async_test
     async def test_disallows_messages_beyond_limit(self):
         """Cases with more than the allowed amount of role mentions."""
         cases = (
diff --git a/tests/bot/test_api.py b/tests/bot/test_api.py
index bdfcc73e4..99e942813 100644
--- a/tests/bot/test_api.py
+++ b/tests/bot/test_api.py
@@ -2,10 +2,9 @@ import unittest
 from unittest.mock import MagicMock
 
 from bot import api
-from tests.helpers import async_test
 
 
-class APIClientTests(unittest.TestCase):
+class APIClientTests(unittest.IsolatedAsyncioTestCase):
     """Tests for the bot's API client."""
 
     @classmethod
@@ -18,7 +17,6 @@ class APIClientTests(unittest.TestCase):
         """The event loop should not be running by default."""
         self.assertFalse(api.loop_is_running())
 
-    @async_test
     async def test_loop_is_running_in_async_context(self):
         """The event loop should be running in an async context."""
         self.assertTrue(api.loop_is_running())
diff --git a/tests/bot/test_converters.py b/tests/bot/test_converters.py
index b2b78d9dd..1e5ca62ae 100644
--- a/tests/bot/test_converters.py
+++ b/tests/bot/test_converters.py
@@ -68,7 +68,7 @@ class ConverterTests(unittest.TestCase):
             ('👋', "Don't be ridiculous, you can't use that character!"),
             ('', "Tag names should not be empty, or filled with whitespace."),
             ('  ', "Tag names should not be empty, or filled with whitespace."),
-            ('42', "Tag names can't be numbers."),
+            ('42', "Tag names must contain at least one letter."),
             ('x' * 128, "Are you insane? That's way too long!"),
         )
 
diff --git a/tests/bot/test_utils.py b/tests/bot/test_utils.py
index 58ae2a81a..d7bcc3ba6 100644
--- a/tests/bot/test_utils.py
+++ b/tests/bot/test_utils.py
@@ -35,18 +35,3 @@ class CaseInsensitiveDictTests(unittest.TestCase):
         instance = utils.CaseInsensitiveDict()
         instance.update({'FOO': 'bar'})
         self.assertEqual(instance['foo'], 'bar')
-
-
-class ChunkTests(unittest.TestCase):
-    """Tests the `chunk` method."""
-
-    def test_empty_chunking(self):
-        """Tests chunking on an empty iterable."""
-        generator = utils.chunks(iterable=[], size=5)
-        self.assertEqual(list(generator), [])
-
-    def test_list_chunking(self):
-        """Tests chunking a non-empty list."""
-        iterable = [1, 2, 3, 4, 5]
-        generator = utils.chunks(iterable=iterable, size=2)
-        self.assertEqual(list(generator), [[1, 2], [3, 4], [5]])
diff --git a/tests/bot/utils/test_time.py b/tests/bot/utils/test_time.py
index 69f35f2f5..694d3a40f 100644
--- a/tests/bot/utils/test_time.py
+++ b/tests/bot/utils/test_time.py
@@ -1,12 +1,11 @@
 import asyncio
 import unittest
 from datetime import datetime, timezone
-from unittest.mock import patch
+from unittest.mock import AsyncMock, patch
 
 from dateutil.relativedelta import relativedelta
 
 from bot.utils import time
-from tests.helpers import AsyncMock
 
 
 class TimeTests(unittest.TestCase):
@@ -44,7 +43,7 @@ class TimeTests(unittest.TestCase):
         for max_units in test_cases:
             with self.subTest(max_units=max_units), self.assertRaises(ValueError) as error:
                 time.humanize_delta(relativedelta(days=2, hours=2), 'hours', max_units)
-                self.assertEqual(str(error), 'max_units must be positive')
+            self.assertEqual(str(error.exception), 'max_units must be positive')
 
     def test_parse_rfc1123(self):
         """Testing parse_rfc1123."""