Merge branch 'master' into compact_free

20 files changed, 1192 insertions, 0 deletions

diff --git a/tests/bot/__init__.py b/tests/bot/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/bot/__init__.py
diff --git a/tests/bot/cogs/__init__.py b/tests/bot/cogs/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/bot/cogs/__init__.py
diff --git a/tests/bot/cogs/sync/__init__.py b/tests/bot/cogs/sync/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/bot/cogs/sync/__init__.py
diff --git a/tests/bot/cogs/sync/test_roles.py b/tests/bot/cogs/sync/test_roles.py
new file mode 100644
index 000000000..27ae27639
--- /dev/null
+++ b/tests/bot/cogs/sync/test_roles.py
@@ -0,0 +1,126 @@
+import unittest
+
+from bot.cogs.sync.syncers import Role, get_roles_for_sync
+
+
+class GetRolesForSyncTests(unittest.TestCase):
+    """Tests constructing the roles to synchronize with the site."""
+
+    def test_get_roles_for_sync_empty_return_for_equal_roles(self):
+        """No roles should be synced when no diff is found."""
+        api_roles = {Role(id=41, name='name', colour=33, permissions=0x8, position=1)}
+        guild_roles = {Role(id=41, name='name', colour=33, permissions=0x8, position=1)}
+
+        self.assertEqual(
+            get_roles_for_sync(guild_roles, api_roles),
+            (set(), set(), set())
+        )
+
+    def test_get_roles_for_sync_returns_roles_to_update_with_non_id_diff(self):
+        """Roles to be synced are returned when non-ID attributes differ."""
+        api_roles = {Role(id=41, name='old name', colour=35, permissions=0x8, position=1)}
+        guild_roles = {Role(id=41, name='new name', colour=33, permissions=0x8, position=2)}
+
+        self.assertEqual(
+            get_roles_for_sync(guild_roles, api_roles),
+            (set(), guild_roles, set())
+        )
+
+    def test_get_roles_only_returns_roles_that_require_update(self):
+        """Roles that require an update should be returned as the second tuple element."""
+        api_roles = {
+            Role(id=41, name='old name', colour=33, permissions=0x8, position=1),
+            Role(id=53, name='other role', colour=55, permissions=0, position=3)
+        }
+        guild_roles = {
+            Role(id=41, name='new name', colour=35, permissions=0x8, position=2),
+            Role(id=53, name='other role', colour=55, permissions=0, position=3)
+        }
+
+        self.assertEqual(
+            get_roles_for_sync(guild_roles, api_roles),
+            (
+                set(),
+                {Role(id=41, name='new name', colour=35, permissions=0x8, position=2)},
+                set(),
+            )
+        )
+
+    def test_get_roles_returns_new_roles_in_first_tuple_element(self):
+        """Newly created roles are returned as the first tuple element."""
+        api_roles = {
+            Role(id=41, name='name', colour=35, permissions=0x8, position=1),
+        }
+        guild_roles = {
+            Role(id=41, name='name', colour=35, permissions=0x8, position=1),
+            Role(id=53, name='other role', colour=55, permissions=0, position=2)
+        }
+
+        self.assertEqual(
+            get_roles_for_sync(guild_roles, api_roles),
+            (
+                {Role(id=53, name='other role', colour=55, permissions=0, position=2)},
+                set(),
+                set(),
+            )
+        )
+
+    def test_get_roles_returns_roles_to_update_and_new_roles(self):
+        """Newly created and updated roles should be returned together."""
+        api_roles = {
+            Role(id=41, name='old name', colour=35, permissions=0x8, position=1),
+        }
+        guild_roles = {
+            Role(id=41, name='new name', colour=40, permissions=0x16, position=2),
+            Role(id=53, name='other role', colour=55, permissions=0, position=3)
+        }
+
+        self.assertEqual(
+            get_roles_for_sync(guild_roles, api_roles),
+            (
+                {Role(id=53, name='other role', colour=55, permissions=0, position=3)},
+                {Role(id=41, name='new name', colour=40, permissions=0x16, position=2)},
+                set(),
+            )
+        )
+
+    def test_get_roles_returns_roles_to_delete(self):
+        """Roles to be deleted should be returned as the third tuple element."""
+        api_roles = {
+            Role(id=41, name='name', colour=35, permissions=0x8, position=1),
+            Role(id=61, name='to delete', colour=99, permissions=0x9, position=2),
+        }
+        guild_roles = {
+            Role(id=41, name='name', colour=35, permissions=0x8, position=1),
+        }
+
+        self.assertEqual(
+            get_roles_for_sync(guild_roles, api_roles),
+            (
+                set(),
+                set(),
+                {Role(id=61, name='to delete', colour=99, permissions=0x9, position=2)},
+            )
+        )
+
+    def test_get_roles_returns_roles_to_delete_update_and_new_roles(self):
+        """When roles were added, updated, and removed, all of them are returned properly."""
+        api_roles = {
+            Role(id=41, name='not changed', colour=35, permissions=0x8, position=1),
+            Role(id=61, name='to delete', colour=99, permissions=0x9, position=2),
+            Role(id=71, name='to update', colour=99, permissions=0x9, position=3),
+        }
+        guild_roles = {
+            Role(id=41, name='not changed', colour=35, permissions=0x8, position=1),
+            Role(id=81, name='to create', colour=99, permissions=0x9, position=4),
+            Role(id=71, name='updated', colour=101, permissions=0x5, position=3),
+        }
+
+        self.assertEqual(
+            get_roles_for_sync(guild_roles, api_roles),
+            (
+                {Role(id=81, name='to create', colour=99, permissions=0x9, position=4)},
+                {Role(id=71, name='updated', colour=101, permissions=0x5, position=3)},
+                {Role(id=61, name='to delete', colour=99, permissions=0x9, position=2)},
+            )
+        )
diff --git a/tests/bot/cogs/sync/test_users.py b/tests/bot/cogs/sync/test_users.py
new file mode 100644
index 000000000..ccaf67490
--- /dev/null
+++ b/tests/bot/cogs/sync/test_users.py
@@ -0,0 +1,84 @@
+import unittest
+
+from bot.cogs.sync.syncers import User, get_users_for_sync
+
+
+def fake_user(**kwargs):
+    kwargs.setdefault('id', 43)
+    kwargs.setdefault('name', 'bob the test man')
+    kwargs.setdefault('discriminator', 1337)
+    kwargs.setdefault('avatar_hash', None)
+    kwargs.setdefault('roles', (666,))
+    kwargs.setdefault('in_guild', True)
+    return User(**kwargs)
+
+
+class GetUsersForSyncTests(unittest.TestCase):
+    """Tests constructing the users to synchronize with the site."""
+
+    def test_get_users_for_sync_returns_nothing_for_empty_params(self):
+        """When no users are given, none are returned."""
+        self.assertEqual(
+            get_users_for_sync({}, {}),
+            (set(), set())
+        )
+
+    def test_get_users_for_sync_returns_nothing_for_equal_users(self):
+        """When no users are updated, none are returned."""
+        api_users = {43: fake_user()}
+        guild_users = {43: fake_user()}
+
+        self.assertEqual(
+            get_users_for_sync(guild_users, api_users),
+            (set(), set())
+        )
+
+    def test_get_users_for_sync_returns_users_to_update_on_non_id_field_diff(self):
+        """When a non-ID-field differs, the user to update is returned."""
+        api_users = {43: fake_user()}
+        guild_users = {43: fake_user(name='new fancy name')}
+
+        self.assertEqual(
+            get_users_for_sync(guild_users, api_users),
+            (set(), {fake_user(name='new fancy name')})
+        )
+
+    def test_get_users_for_sync_returns_users_to_create_with_new_ids_on_guild(self):
+        """When new users join the guild, they are returned as the first tuple element."""
+        api_users = {43: fake_user()}
+        guild_users = {43: fake_user(), 63: fake_user(id=63)}
+
+        self.assertEqual(
+            get_users_for_sync(guild_users, api_users),
+            ({fake_user(id=63)}, set())
+        )
+
+    def test_get_users_for_sync_updates_in_guild_field_on_user_leave(self):
+        """When a user leaves the guild, the `in_guild` flag is updated to `False`."""
+        api_users = {43: fake_user(), 63: fake_user(id=63)}
+        guild_users = {43: fake_user()}
+
+        self.assertEqual(
+            get_users_for_sync(guild_users, api_users),
+            (set(), {fake_user(id=63, in_guild=False)})
+        )
+
+    def test_get_users_for_sync_updates_and_creates_users_as_needed(self):
+        """When one user left and another one was updated, both are returned."""
+        api_users = {43: fake_user()}
+        guild_users = {63: fake_user(id=63)}
+
+        self.assertEqual(
+            get_users_for_sync(guild_users, api_users),
+            ({fake_user(id=63)}, {fake_user(in_guild=False)})
+        )
+
+    def test_get_users_for_sync_does_not_duplicate_update_users(self):
+        """When the API knows a user the guild doesn't, nothing is performed."""
+        api_users = {43: fake_user(in_guild=False)}
+        guild_users = {}
+
+        self.assertEqual(
+            get_users_for_sync(guild_users, api_users),
+            (set(), set())
+        )
diff --git a/tests/bot/cogs/test_antispam.py b/tests/bot/cogs/test_antispam.py
new file mode 100644
index 000000000..ce5472c71
--- /dev/null
+++ b/tests/bot/cogs/test_antispam.py
@@ -0,0 +1,35 @@
+import unittest
+
+from bot.cogs import antispam
+
+
+class AntispamConfigurationValidationTests(unittest.TestCase):
+    """Tests validation of the antispam cog configuration."""
+
+    def test_default_antispam_config_is_valid(self):
+        """The default antispam configuration is valid."""
+        validation_errors = antispam.validate_config()
+        self.assertEqual(validation_errors, {})
+
+    def test_unknown_rule_returns_error(self):
+        """Configuring an unknown rule returns an error."""
+        self.assertEqual(
+            antispam.validate_config({'invalid-rule': {}}),
+            {'invalid-rule': "`invalid-rule` is not recognized as an antispam rule."}
+        )
+
+    def test_missing_keys_returns_error(self):
+        """Not configuring required keys returns an error."""
+        keys = (('interval', 'max'), ('max', 'interval'))
+        for configured_key, unconfigured_key in keys:
+            with self.subTest(
+                configured_key=configured_key,
+                unconfigured_key=unconfigured_key
+            ):
+                config = {'burst': {configured_key: 10}}
+                error = f"Key `{unconfigured_key}` is required but not set for rule `burst`"
+
+                self.assertEqual(
+                    antispam.validate_config(config),
+                    {'burst': error}
+                )
diff --git a/tests/bot/cogs/test_information.py b/tests/bot/cogs/test_information.py
new file mode 100644
index 000000000..9bbd35a91
--- /dev/null
+++ b/tests/bot/cogs/test_information.py
@@ -0,0 +1,164 @@
+import asyncio
+import textwrap
+import unittest
+import unittest.mock
+
+import discord
+
+from bot import constants
+from bot.cogs import information
+from tests.helpers import AsyncMock, MockBot, MockContext, MockGuild, MockMember, MockRole
+
+
+class InformationCogTests(unittest.TestCase):
+    """Tests the Information cog."""
+
+    @classmethod
+    def setUpClass(cls):
+        cls.moderator_role = MockRole(name="Moderator", role_id=constants.Roles.moderator)
+
+    def setUp(self):
+        """Sets up fresh objects for each test."""
+        self.bot = MockBot()
+
+        self.cog = information.Information(self.bot)
+
+        self.ctx = MockContext()
+        self.ctx.author.roles.append(self.moderator_role)
+
+    def test_roles_command_command(self):
+        """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 = AsyncMock()
+        self.cog.roles_info.can_run.return_value = True
+
+        coroutine = self.cog.roles_info.callback(self.cog, self.ctx)
+
+        self.assertIsNone(asyncio.run(coroutine))
+        self.ctx.send.assert_called_once()
+
+        _, kwargs = self.ctx.send.call_args
+        embed = kwargs.pop('embed')
+
+        self.assertEqual(embed.title, "Role information")
+        self.assertEqual(embed.colour, discord.Colour.blurple())
+        self.assertEqual(embed.description, f"`{self.moderator_role.id}` - {self.moderator_role.mention}\n")
+        self.assertEqual(embed.footer.text, "Total roles: 1")
+
+    def test_role_info_command(self):
+        """Tests the `role info` command."""
+        dummy_role = MockRole(
+            name="Dummy",
+            role_id=112233445566778899,
+            colour=discord.Colour.blurple(),
+            position=10,
+            members=[self.ctx.author],
+            permissions=discord.Permissions(0)
+        )
+
+        admin_role = MockRole(
+            name="Admins",
+            role_id=998877665544332211,
+            colour=discord.Colour.red(),
+            position=3,
+            members=[self.ctx.author],
+            permissions=discord.Permissions(0),
+        )
+
+        self.ctx.guild.roles.append([dummy_role, admin_role])
+
+        self.cog.role_info.can_run = AsyncMock()
+        self.cog.role_info.can_run.return_value = True
+
+        coroutine = self.cog.role_info.callback(self.cog, self.ctx, dummy_role, admin_role)
+
+        self.assertIsNone(asyncio.run(coroutine))
+
+        self.assertEqual(self.ctx.send.call_count, 2)
+
+        (_, dummy_kwargs), (_, admin_kwargs) = self.ctx.send.call_args_list
+
+        dummy_embed = dummy_kwargs["embed"]
+        admin_embed = admin_kwargs["embed"]
+
+        self.assertEqual(dummy_embed.title, "Dummy info")
+        self.assertEqual(dummy_embed.colour, discord.Colour.blurple())
+
+        self.assertEqual(dummy_embed.fields[0].value, str(dummy_role.id))
+        self.assertEqual(dummy_embed.fields[1].value, f"#{dummy_role.colour.value:0>6x}")
+        self.assertEqual(dummy_embed.fields[2].value, "0.63 0.48 218")
+        self.assertEqual(dummy_embed.fields[3].value, "1")
+        self.assertEqual(dummy_embed.fields[4].value, "10")
+        self.assertEqual(dummy_embed.fields[5].value, "0")
+
+        self.assertEqual(admin_embed.title, "Admins info")
+        self.assertEqual(admin_embed.colour, discord.Colour.red())
+
+    @unittest.mock.patch('bot.cogs.information.time_since')
+    def test_server_info_command(self, time_since_patch):
+        time_since_patch.return_value = '2 days ago'
+
+        self.ctx.guild = MockGuild(
+            features=('lemons', 'apples'),
+            region="The Moon",
+            roles=[self.moderator_role],
+            channels=[
+                discord.TextChannel(
+                    state={},
+                    guild=self.ctx.guild,
+                    data={'id': 42, 'name': 'lemons-offering', 'position': 22, 'type': 'text'}
+                ),
+                discord.CategoryChannel(
+                    state={},
+                    guild=self.ctx.guild,
+                    data={'id': 5125, 'name': 'the-lemon-collection', 'position': 22, 'type': 'category'}
+                ),
+                discord.VoiceChannel(
+                    state={},
+                    guild=self.ctx.guild,
+                    data={'id': 15290, 'name': 'listen-to-lemon', 'position': 22, 'type': 'voice'}
+                )
+            ],
+            members=[
+                *(MockMember(status='online') for _ in range(2)),
+                *(MockMember(status='idle') for _ in range(1)),
+                *(MockMember(status='dnd') for _ in range(4)),
+                *(MockMember(status='offline') for _ in range(3)),
+            ],
+            member_count=1_234,
+            icon_url='a-lemon.jpg',
+        )
+
+        coroutine = self.cog.server_info.callback(self.cog, self.ctx)
+        self.assertIsNone(asyncio.run(coroutine))
+
+        time_since_patch.assert_called_once_with(self.ctx.guild.created_at, precision='days')
+        _, kwargs = self.ctx.send.call_args
+        embed = kwargs.pop('embed')
+        self.assertEqual(embed.colour, discord.Colour.blurple())
+        self.assertEqual(
+            embed.description,
+            textwrap.dedent(
+                f"""
+                **Server information**
+                Created: {time_since_patch.return_value}
+                Voice region: {self.ctx.guild.region}
+                Features: {', '.join(self.ctx.guild.features)}
+
+                **Counts**
+                Members: {self.ctx.guild.member_count:,}
+                Roles: {len(self.ctx.guild.roles)}
+                Text: 1
+                Voice: 1
+                Channel categories: 1
+
+                **Members**
+                {constants.Emojis.status_online} 2
+                {constants.Emojis.status_idle} 1
+                {constants.Emojis.status_dnd} 4
+                {constants.Emojis.status_offline} 3
+                """
+            )
+        )
+        self.assertEqual(embed.thumbnail.url, 'a-lemon.jpg')
diff --git a/tests/bot/cogs/test_security.py b/tests/bot/cogs/test_security.py
new file mode 100644
index 000000000..efa7a50b1
--- /dev/null
+++ b/tests/bot/cogs/test_security.py
@@ -0,0 +1,59 @@
+import logging
+import unittest
+from unittest.mock import MagicMock
+
+from discord.ext.commands import NoPrivateMessage
+
+from bot.cogs import security
+from tests.helpers import MockBot, MockContext
+
+
+class SecurityCogTests(unittest.TestCase):
+    """Tests the `Security` cog."""
+
+    def setUp(self):
+        """Attach an instance of the cog to the class for tests."""
+        self.bot = MockBot()
+        self.cog = security.Security(self.bot)
+        self.ctx = MockContext()
+
+    def test_check_additions(self):
+        """The cog should add its checks after initialization."""
+        self.bot.check.assert_any_call(self.cog.check_on_guild)
+        self.bot.check.assert_any_call(self.cog.check_not_bot)
+
+    def test_check_not_bot_returns_false_for_humans(self):
+        """The bot check should return `True` when invoked with human authors."""
+        self.ctx.author.bot = False
+        self.assertTrue(self.cog.check_not_bot(self.ctx))
+
+    def test_check_not_bot_returns_true_for_robots(self):
+        """The bot check should return `False` when invoked with robotic authors."""
+        self.ctx.author.bot = True
+        self.assertFalse(self.cog.check_not_bot(self.ctx))
+
+    def test_check_on_guild_raises_when_outside_of_guild(self):
+        """When invoked outside of a guild, `check_on_guild` should cause an error."""
+        self.ctx.guild = None
+
+        with self.assertRaises(NoPrivateMessage, msg="This command cannot be used in private messages."):
+            self.cog.check_on_guild(self.ctx)
+
+    def test_check_on_guild_returns_true_inside_of_guild(self):
+        """When invoked inside of a guild, `check_on_guild` should return `True`."""
+        self.ctx.guild = "lemon's lemonade stand"
+        self.assertTrue(self.cog.check_on_guild(self.ctx))
+
+
+class SecurityCogLoadTests(unittest.TestCase):
+    """Tests loading the `Security` cog."""
+
+    def test_security_cog_load(self):
+        """Cog loading logs a message at `INFO` level."""
+        bot = MagicMock()
+        with self.assertLogs(logger='bot.cogs.security', level=logging.INFO) as cm:
+            security.setup(bot)
+            bot.add_cog.assert_called_once()
+
+        [line] = cm.output
+        self.assertIn("Cog loaded: Security", line)
diff --git a/tests/bot/cogs/test_token_remover.py b/tests/bot/cogs/test_token_remover.py
new file mode 100644
index 000000000..dfb1bafc9
--- /dev/null
+++ b/tests/bot/cogs/test_token_remover.py
@@ -0,0 +1,135 @@
+import asyncio
+import logging
+import unittest
+from unittest.mock import MagicMock
+
+from discord import Colour
+
+from bot.cogs.token_remover import (
+    DELETION_MESSAGE_TEMPLATE,
+    TokenRemover,
+    setup as setup_cog,
+)
+from bot.constants import Channels, Colours, Event, Icons
+from tests.helpers import AsyncMock, MockBot, MockMessage
+
+
+class TokenRemoverTests(unittest.TestCase):
+    """Tests the `TokenRemover` cog."""
+
+    def setUp(self):
+        """Adds the cog, a bot, and a message to the instance for usage in tests."""
+        self.bot = MockBot()
+        self.bot.get_cog.return_value = MagicMock()
+        self.bot.get_cog.return_value.send_log_message = AsyncMock()
+        self.cog = TokenRemover(bot=self.bot)
+
+        self.msg = MockMessage(message_id=555, content='')
+        self.msg.author.__str__ = MagicMock()
+        self.msg.author.__str__.return_value = 'lemon'
+        self.msg.author.bot = False
+        self.msg.author.avatar_url_as.return_value = 'picture-lemon.png'
+        self.msg.author.id = 42
+        self.msg.author.mention = '@lemon'
+        self.msg.channel.mention = "#lemonade-stand"
+
+    def test_is_valid_user_id_is_true_for_numeric_content(self):
+        """A string decoding to numeric characters is a valid user ID."""
+        # MTIz = base64(123)
+        self.assertTrue(TokenRemover.is_valid_user_id('MTIz'))
+
+    def test_is_valid_user_id_is_false_for_alphabetic_content(self):
+        """A string decoding to alphabetic characters is not a valid user ID."""
+        # YWJj = base64(abc)
+        self.assertFalse(TokenRemover.is_valid_user_id('YWJj'))
+
+    def test_is_valid_timestamp_is_true_for_valid_timestamps(self):
+        """A string decoding to a valid timestamp should be recognized as such."""
+        self.assertTrue(TokenRemover.is_valid_timestamp('DN9r_A'))
+
+    def test_is_valid_timestamp_is_false_for_invalid_values(self):
+        """A string not decoding to a valid timestamp should not be recognized as such."""
+        # MTIz = base64(123)
+        self.assertFalse(TokenRemover.is_valid_timestamp('MTIz'))
+
+    def test_mod_log_property(self):
+        """The `mod_log` property should ask the bot to return the `ModLog` cog."""
+        self.bot.get_cog.return_value = 'lemon'
+        self.assertEqual(self.cog.mod_log, self.bot.get_cog.return_value)
+        self.bot.get_cog.assert_called_once_with('ModLog')
+
+    def test_ignores_bot_messages(self):
+        """When the message event handler is called with a bot message, nothing is done."""
+        self.msg.author.bot = True
+        coroutine = self.cog.on_message(self.msg)
+        self.assertIsNone(asyncio.run(coroutine))
+
+    def test_ignores_messages_without_tokens(self):
+        """Messages without anything looking like a token are ignored."""
+        for content in ('', 'lemon wins'):
+            with self.subTest(content=content):
+                self.msg.content = content
+                coroutine = self.cog.on_message(self.msg)
+                self.assertIsNone(asyncio.run(coroutine))
+
+    def test_ignores_messages_with_invalid_tokens(self):
+        """Messages with values that are invalid tokens are ignored."""
+        for content in ('foo.bar.baz', 'x.y.'):
+            with self.subTest(content=content):
+                self.msg.content = content
+                coroutine = self.cog.on_message(self.msg)
+                self.assertIsNone(asyncio.run(coroutine))
+
+    def test_censors_valid_tokens(self):
+        """Valid tokens are censored."""
+        cases = (
+            # (content, censored_token)
+            ('MTIz.DN9R_A.xyz', 'MTIz.DN9R_A.xxx'),
+        )
+
+        for content, censored_token in cases:
+            with self.subTest(content=content, censored_token=censored_token):
+                self.msg.content = content
+                coroutine = self.cog.on_message(self.msg)
+                with self.assertLogs(logger='bot.cogs.token_remover', level=logging.DEBUG) as cm:
+                    self.assertIsNone(asyncio.run(coroutine))  # no return value
+
+                [line] = cm.output
+                log_message = (
+                    "Censored a seemingly valid token sent by "
+                    "lemon (`42`) in #lemonade-stand, "
+                    f"token was `{censored_token}`"
+                )
+                self.assertIn(log_message, line)
+
+                self.msg.delete.assert_called_once_with()
+                self.msg.channel.send.assert_called_once_with(
+                    DELETION_MESSAGE_TEMPLATE.format(mention='@lemon')
+                )
+                self.bot.get_cog.assert_called_with('ModLog')
+                self.msg.author.avatar_url_as.assert_called_once_with(static_format='png')
+
+                mod_log = self.bot.get_cog.return_value
+                mod_log.ignore.assert_called_once_with(Event.message_delete, self.msg.id)
+                mod_log.send_log_message.assert_called_once_with(
+                    icon_url=Icons.token_removed,
+                    colour=Colour(Colours.soft_red),
+                    title="Token removed!",
+                    text=log_message,
+                    thumbnail='picture-lemon.png',
+                    channel_id=Channels.mod_alerts
+                )
+
+
+class TokenRemoverSetupTests(unittest.TestCase):
+    """Tests setup of the `TokenRemover` cog."""
+
+    def test_setup(self):
+        """Setup of the cog should log a message at `INFO` level."""
+        bot = MockBot()
+        with self.assertLogs(logger='bot.cogs.token_remover', level=logging.INFO) as cm:
+            setup_cog(bot)
+
+        [line] = cm.output
+        bot.add_cog.assert_called_once()
+        self.assertIn("Cog loaded: TokenRemover", line)
diff --git a/tests/bot/patches/__init__.py b/tests/bot/patches/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/bot/patches/__init__.py
diff --git a/tests/bot/resources/__init__.py b/tests/bot/resources/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/bot/resources/__init__.py
diff --git a/tests/bot/resources/test_resources.py b/tests/bot/resources/test_resources.py
new file mode 100644
index 000000000..73937cfa6
--- /dev/null
+++ b/tests/bot/resources/test_resources.py
@@ -0,0 +1,17 @@
+import json
+import unittest
+from pathlib import Path
+
+
+class ResourceValidationTests(unittest.TestCase):
+    """Validates resources used by the bot."""
+    def test_stars_valid(self):
+        """The resource `bot/resources/stars.json` should contain a list of strings."""
+        path = Path('bot', 'resources', 'stars.json')
+        content = path.read_text()
+        data = json.loads(content)
+
+        self.assertIsInstance(data, list)
+        for name in data:
+            with self.subTest(name=name):
+                self.assertIsInstance(name, str)
diff --git a/tests/bot/rules/__init__.py b/tests/bot/rules/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/bot/rules/__init__.py
diff --git a/tests/bot/rules/test_attachments.py b/tests/bot/rules/test_attachments.py
new file mode 100644
index 000000000..4bb0acf7c
--- /dev/null
+++ b/tests/bot/rules/test_attachments.py
@@ -0,0 +1,52 @@
+import asyncio
+import unittest
+from dataclasses import dataclass
+from typing import Any, List
+
+from bot.rules import attachments
+
+
+# Using `MagicMock` sadly doesn't work for this usecase
+# since it's __eq__ compares the MagicMock's ID. We just
+# want to compare the actual attributes we set.
+@dataclass
+class FakeMessage:
+    author: str
+    attachments: List[Any]
+
+
+def msg(total_attachments: int) -> FakeMessage:
+    return FakeMessage(author='lemon', attachments=list(range(total_attachments)))
+
+
+class AttachmentRuleTests(unittest.TestCase):
+    """Tests applying the `attachment` antispam rule."""
+
+    def test_allows_messages_without_too_many_attachments(self):
+        """Messages without too many attachments are allowed as-is."""
+        cases = (
+            (msg(0), msg(0), msg(0)),
+            (msg(2), msg(2)),
+            (msg(0),),
+        )
+
+        for last_message, *recent_messages in cases:
+            with self.subTest(last_message=last_message, recent_messages=recent_messages):
+                coro = attachments.apply(last_message, recent_messages, {'max': 5})
+                self.assertIsNone(asyncio.run(coro))
+
+    def test_disallows_messages_with_too_many_attachments(self):
+        """Messages with too many attachments trigger the rule."""
+        cases = (
+            ((msg(4), msg(0), msg(6)), [msg(4), msg(6)], 10),
+            ((msg(6),), [msg(6)], 6),
+            ((msg(1),) * 6, [msg(1)] * 6, 6),
+        )
+        for messages, relevant_messages, total in cases:
+            with self.subTest(messages=messages, relevant_messages=relevant_messages, total=total):
+                last_message, *recent_messages = messages
+                coro = attachments.apply(last_message, recent_messages, {'max': 5})
+                self.assertEqual(
+                    asyncio.run(coro),
+                    (f"sent {total} attachments in 5s", ('lemon',), relevant_messages)
+                )
diff --git a/tests/bot/test_api.py b/tests/bot/test_api.py
new file mode 100644
index 000000000..e0ede0eb1
--- /dev/null
+++ b/tests/bot/test_api.py
@@ -0,0 +1,134 @@
+import logging
+import unittest
+from unittest.mock import MagicMock, patch
+
+from bot import api
+from tests.base import LoggingTestCase
+from tests.helpers import async_test
+
+
+class APIClientTests(unittest.TestCase):
+    """Tests for the bot's API client."""
+
+    @classmethod
+    def setUpClass(cls):
+        """Sets up the shared fixtures for the tests."""
+        cls.error_api_response = MagicMock()
+        cls.error_api_response.status = 999
+
+    def test_loop_is_not_running_by_default(self):
+        """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())
+
+    def test_response_code_error_default_initialization(self):
+        """Test the default initialization of `ResponseCodeError` without `text` or `json`"""
+        error = api.ResponseCodeError(response=self.error_api_response)
+
+        self.assertIs(error.status, self.error_api_response.status)
+        self.assertEqual(error.response_json, {})
+        self.assertEqual(error.response_text, "")
+        self.assertIs(error.response, self.error_api_response)
+
+    def test_responde_code_error_string_representation_default_initialization(self):
+        """Test the string representation of `ResponseCodeError` initialized without text or json."""
+        error = api.ResponseCodeError(response=self.error_api_response)
+        self.assertEqual(str(error), f"Status: {self.error_api_response.status} Response: ")
+
+    def test_response_code_error_initialization_with_json(self):
+        """Test the initialization of `ResponseCodeError` with json."""
+        json_data = {'hello': 'world'}
+        error = api.ResponseCodeError(
+            response=self.error_api_response,
+            response_json=json_data,
+        )
+        self.assertEqual(error.response_json, json_data)
+        self.assertEqual(error.response_text, "")
+
+    def test_response_code_error_string_representation_with_nonempty_response_json(self):
+        """Test the string representation of `ResponseCodeError` initialized with json."""
+        json_data = {'hello': 'world'}
+        error = api.ResponseCodeError(
+            response=self.error_api_response,
+            response_json=json_data
+        )
+        self.assertEqual(str(error), f"Status: {self.error_api_response.status} Response: {json_data}")
+
+    def test_response_code_error_initialization_with_text(self):
+        """Test the initialization of `ResponseCodeError` with text."""
+        text_data = 'Lemon will eat your soul'
+        error = api.ResponseCodeError(
+            response=self.error_api_response,
+            response_text=text_data,
+        )
+        self.assertEqual(error.response_text, text_data)
+        self.assertEqual(error.response_json, {})
+
+    def test_response_code_error_string_representation_with_nonempty_response_text(self):
+        """Test the string representation of `ResponseCodeError` initialized with text."""
+        text_data = 'Lemon will eat your soul'
+        error = api.ResponseCodeError(
+            response=self.error_api_response,
+            response_text=text_data
+        )
+        self.assertEqual(str(error), f"Status: {self.error_api_response.status} Response: {text_data}")
+
+
+class LoggingHandlerTests(LoggingTestCase):
+    """Tests the bot's API Log Handler."""
+
+    @classmethod
+    def setUpClass(cls):
+        cls.debug_log_record = logging.LogRecord(
+            name='my.logger', level=logging.DEBUG,
+            pathname='my/logger.py', lineno=666,
+            msg="Lemon wins", args=(),
+            exc_info=None
+        )
+
+        cls.trace_log_record = logging.LogRecord(
+            name='my.logger', level=logging.TRACE,
+            pathname='my/logger.py', lineno=666,
+            msg="This will not be logged", args=(),
+            exc_info=None
+        )
+
+    def setUp(self):
+        self.log_handler = api.APILoggingHandler(None)
+
+    def test_emit_appends_to_queue_with_stopped_event_loop(self):
+        """Test if `APILoggingHandler.emit` appends to queue when the event loop is not running."""
+        with patch("bot.api.APILoggingHandler.ship_off") as ship_off:
+            # Patch `ship_off` to ease testing against the return value of this coroutine.
+            ship_off.return_value = 42
+            self.log_handler.emit(self.debug_log_record)
+
+        self.assertListEqual(self.log_handler.queue, [42])
+
+    def test_emit_ignores_less_than_debug(self):
+        """`APILoggingHandler.emit` should not queue logs with a log level lower than DEBUG."""
+        self.log_handler.emit(self.trace_log_record)
+        self.assertListEqual(self.log_handler.queue, [])
+
+    def test_schedule_queued_tasks_for_empty_queue(self):
+        """`APILoggingHandler` should not schedule anything when the queue is empty."""
+        with self.assertNotLogs(level=logging.DEBUG):
+            self.log_handler.schedule_queued_tasks()
+
+    def test_schedule_queued_tasks_for_nonempty_queue(self):
+        """`APILoggingHandler` should schedule logs when the queue is not empty."""
+        with self.assertLogs(level=logging.DEBUG) as logs, patch('asyncio.create_task') as create_task:
+            self.log_handler.queue = [555]
+            self.log_handler.schedule_queued_tasks()
+            self.assertListEqual(self.log_handler.queue, [])
+            create_task.assert_called_once_with(555)
+
+            [record] = logs.records
+            self.assertEqual(record.message, "Scheduled 1 pending logging tasks.")
+            self.assertEqual(record.levelno, logging.DEBUG)
+            self.assertEqual(record.name, 'bot.api')
+            self.assertIn('via_handler', record.__dict__)
diff --git a/tests/bot/test_constants.py b/tests/bot/test_constants.py
new file mode 100644
index 000000000..dae7c066c
--- /dev/null
+++ b/tests/bot/test_constants.py
@@ -0,0 +1,26 @@
+import inspect
+import unittest
+
+from bot import constants
+
+
+class ConstantsTests(unittest.TestCase):
+    """Tests for our constants."""
+
+    def test_section_configuration_matches_type_specification(self):
+        """The section annotations should match the actual types of the sections."""
+
+        sections = (
+            cls
+            for (name, cls) in inspect.getmembers(constants)
+            if hasattr(cls, 'section') and isinstance(cls, type)
+        )
+        for section in sections:
+            for name, annotation in section.__annotations__.items():
+                with self.subTest(section=section, name=name, annotation=annotation):
+                    value = getattr(section, name)
+
+                    if getattr(annotation, '_name', None) in ('Dict', 'List'):
+                        self.skipTest("Cannot validate containers yet.")
+
+                    self.assertIsInstance(value, annotation)
diff --git a/tests/bot/test_converters.py b/tests/bot/test_converters.py
new file mode 100644
index 000000000..b2b78d9dd
--- /dev/null
+++ b/tests/bot/test_converters.py
@@ -0,0 +1,273 @@
+import asyncio
+import datetime
+import unittest
+from unittest.mock import MagicMock, patch
+
+from dateutil.relativedelta import relativedelta
+from discord.ext.commands import BadArgument
+
+from bot.converters import (
+    Duration,
+    ISODateTime,
+    TagContentConverter,
+    TagNameConverter,
+    ValidPythonIdentifier,
+)
+
+
+class ConverterTests(unittest.TestCase):
+    """Tests our custom argument converters."""
+
+    @classmethod
+    def setUpClass(cls):
+        cls.context = MagicMock
+        cls.context.author = 'bob'
+
+        cls.fixed_utc_now = datetime.datetime.fromisoformat('2019-01-01T00:00:00')
+
+    def test_tag_content_converter_for_valid(self):
+        """TagContentConverter should return correct values for valid input."""
+        test_values = (
+            ('hello', 'hello'),
+            ('  h ello  ', 'h ello'),
+        )
+
+        for content, expected_conversion in test_values:
+            with self.subTest(content=content, expected_conversion=expected_conversion):
+                conversion = asyncio.run(TagContentConverter.convert(self.context, content))
+                self.assertEqual(conversion, expected_conversion)
+
+    def test_tag_content_converter_for_invalid(self):
+        """TagContentConverter should raise the proper exception for invalid input."""
+        test_values = (
+            ('', "Tag contents should not be empty, or filled with whitespace."),
+            ('   ', "Tag contents should not be empty, or filled with whitespace."),
+        )
+
+        for value, exception_message in test_values:
+            with self.subTest(tag_content=value, exception_message=exception_message):
+                with self.assertRaises(BadArgument, msg=exception_message):
+                    asyncio.run(TagContentConverter.convert(self.context, value))
+
+    def test_tag_name_converter_for_valid(self):
+        """TagNameConverter should return the correct values for valid tag names."""
+        test_values = (
+            ('tracebacks', 'tracebacks'),
+            ('Tracebacks', 'tracebacks'),
+            ('  Tracebacks  ', 'tracebacks'),
+        )
+
+        for name, expected_conversion in test_values:
+            with self.subTest(name=name, expected_conversion=expected_conversion):
+                conversion = asyncio.run(TagNameConverter.convert(self.context, name))
+                self.assertEqual(conversion, expected_conversion)
+
+    def test_tag_name_converter_for_invalid(self):
+        """TagNameConverter should raise the correct exception for invalid tag names."""
+        test_values = (
+            ('👋', "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."),
+            ('x' * 128, "Are you insane? That's way too long!"),
+        )
+
+        for invalid_name, exception_message in test_values:
+            with self.subTest(invalid_name=invalid_name, exception_message=exception_message):
+                with self.assertRaises(BadArgument, msg=exception_message):
+                    asyncio.run(TagNameConverter.convert(self.context, invalid_name))
+
+    def test_valid_python_identifier_for_valid(self):
+        """ValidPythonIdentifier returns valid identifiers unchanged."""
+        test_values = ('foo', 'lemon')
+
+        for name in test_values:
+            with self.subTest(identifier=name):
+                conversion = asyncio.run(ValidPythonIdentifier.convert(self.context, name))
+                self.assertEqual(name, conversion)
+
+    def test_valid_python_identifier_for_invalid(self):
+        """ValidPythonIdentifier raises the proper exception for invalid identifiers."""
+        test_values = ('nested.stuff', '#####')
+
+        for name in test_values:
+            with self.subTest(identifier=name):
+                exception_message = f'`{name}` is not a valid Python identifier'
+                with self.assertRaises(BadArgument, msg=exception_message):
+                    asyncio.run(ValidPythonIdentifier.convert(self.context, name))
+
+    def test_duration_converter_for_valid(self):
+        """Duration returns the correct `datetime` for valid duration strings."""
+        test_values = (
+            # Simple duration strings
+            ('1Y', {"years": 1}),
+            ('1y', {"years": 1}),
+            ('1year', {"years": 1}),
+            ('1years', {"years": 1}),
+            ('1m', {"months": 1}),
+            ('1month', {"months": 1}),
+            ('1months', {"months": 1}),
+            ('1w', {"weeks": 1}),
+            ('1W', {"weeks": 1}),
+            ('1week', {"weeks": 1}),
+            ('1weeks', {"weeks": 1}),
+            ('1d', {"days": 1}),
+            ('1D', {"days": 1}),
+            ('1day', {"days": 1}),
+            ('1days', {"days": 1}),
+            ('1h', {"hours": 1}),
+            ('1H', {"hours": 1}),
+            ('1hour', {"hours": 1}),
+            ('1hours', {"hours": 1}),
+            ('1M', {"minutes": 1}),
+            ('1minute', {"minutes": 1}),
+            ('1minutes', {"minutes": 1}),
+            ('1s', {"seconds": 1}),
+            ('1S', {"seconds": 1}),
+            ('1second', {"seconds": 1}),
+            ('1seconds', {"seconds": 1}),
+
+            # Complex duration strings
+            (
+                '1y1m1w1d1H1M1S',
+                {
+                    "years": 1,
+                    "months": 1,
+                    "weeks": 1,
+                    "days": 1,
+                    "hours": 1,
+                    "minutes": 1,
+                    "seconds": 1
+                }
+            ),
+            ('5y100S', {"years": 5, "seconds": 100}),
+            ('2w28H', {"weeks": 2, "hours": 28}),
+
+            # Duration strings with spaces
+            ('1 year 2 months', {"years": 1, "months": 2}),
+            ('1d 2H', {"days": 1, "hours": 2}),
+            ('1 week2 days', {"weeks": 1, "days": 2}),
+        )
+
+        converter = Duration()
+
+        for duration, duration_dict in test_values:
+            expected_datetime = self.fixed_utc_now + relativedelta(**duration_dict)
+
+            with patch('bot.converters.datetime') as mock_datetime:
+                mock_datetime.utcnow.return_value = self.fixed_utc_now
+
+                with self.subTest(duration=duration, duration_dict=duration_dict):
+                    converted_datetime = asyncio.run(converter.convert(self.context, duration))
+                    self.assertEqual(converted_datetime, expected_datetime)
+
+    def test_duration_converter_for_invalid(self):
+        """Duration raises the right exception for invalid duration strings."""
+        test_values = (
+            # Units in wrong order
+            ('1d1w'),
+            ('1s1y'),
+
+            # Duplicated units
+            ('1 year 2 years'),
+            ('1 M 10 minutes'),
+
+            # Unknown substrings
+            ('1MVes'),
+            ('1y3breads'),
+
+            # Missing amount
+            ('ym'),
+
+            # Incorrect whitespace
+            (" 1y"),
+            ("1S "),
+            ("1y  1m"),
+
+            # Garbage
+            ('Guido van Rossum'),
+            ('lemon lemon lemon lemon lemon lemon lemon'),
+        )
+
+        converter = Duration()
+
+        for invalid_duration in test_values:
+            with self.subTest(invalid_duration=invalid_duration):
+                exception_message = f'`{invalid_duration}` is not a valid duration string.'
+                with self.assertRaises(BadArgument, msg=exception_message):
+                    asyncio.run(converter.convert(self.context, invalid_duration))
+
+    def test_isodatetime_converter_for_valid(self):
+        """ISODateTime converter returns correct datetime for valid datetime string."""
+        test_values = (
+            # `YYYY-mm-ddTHH:MM:SSZ` | `YYYY-mm-dd HH:MM:SSZ`
+            ('2019-09-02T02:03:05Z', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+            ('2019-09-02 02:03:05Z', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+
+            # `YYYY-mm-ddTHH:MM:SS±HH:MM` | `YYYY-mm-dd HH:MM:SS±HH:MM`
+            ('2019-09-02T03:18:05+01:15', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+            ('2019-09-02 03:18:05+01:15', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+            ('2019-09-02T00:48:05-01:15', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+            ('2019-09-02 00:48:05-01:15', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+
+            # `YYYY-mm-ddTHH:MM:SS±HHMM` | `YYYY-mm-dd HH:MM:SS±HHMM`
+            ('2019-09-02T03:18:05+0115', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+            ('2019-09-02 03:18:05+0115', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+            ('2019-09-02T00:48:05-0115', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+            ('2019-09-02 00:48:05-0115', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+
+            # `YYYY-mm-ddTHH:MM:SS±HH` | `YYYY-mm-dd HH:MM:SS±HH`
+            ('2019-09-02 03:03:05+01', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+            ('2019-09-02T01:03:05-01', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+
+            # `YYYY-mm-ddTHH:MM:SS` | `YYYY-mm-dd HH:MM:SS`
+            ('2019-09-02T02:03:05', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+            ('2019-09-02 02:03:05', datetime.datetime(2019, 9, 2, 2, 3, 5)),
+
+            # `YYYY-mm-ddTHH:MM` | `YYYY-mm-dd HH:MM`
+            ('2019-11-12T09:15', datetime.datetime(2019, 11, 12, 9, 15)),
+            ('2019-11-12 09:15', datetime.datetime(2019, 11, 12, 9, 15)),
+
+            # `YYYY-mm-dd`
+            ('2019-04-01', datetime.datetime(2019, 4, 1)),
+
+            # `YYYY-mm`
+            ('2019-02-01', datetime.datetime(2019, 2, 1)),
+
+            # `YYYY`
+            ('2025', datetime.datetime(2025, 1, 1)),
+        )
+
+        converter = ISODateTime()
+
+        for datetime_string, expected_dt in test_values:
+            with self.subTest(datetime_string=datetime_string, expected_dt=expected_dt):
+                converted_dt = asyncio.run(converter.convert(self.context, datetime_string))
+                self.assertIsNone(converted_dt.tzinfo)
+                self.assertEqual(converted_dt, expected_dt)
+
+    def test_isodatetime_converter_for_invalid(self):
+        """ISODateTime converter raises the correct exception for invalid datetime strings."""
+        test_values = (
+            # Make sure it doesn't interfere with the Duration converter
+            ('1Y'),
+            ('1d'),
+            ('1H'),
+
+            # Check if it fails when only providing the optional time part
+            ('10:10:10'),
+            ('10:00'),
+
+            # Invalid date format
+            ('19-01-01'),
+
+            # Other non-valid strings
+            ('fisk the tag master'),
+        )
+
+        converter = ISODateTime()
+        for datetime_string in test_values:
+            with self.subTest(datetime_string=datetime_string):
+                exception_message = f"`{datetime_string}` is not a valid ISO-8601 datetime string"
+                with self.assertRaises(BadArgument, msg=exception_message):
+                    asyncio.run(converter.convert(self.context, datetime_string))
diff --git a/tests/bot/test_pagination.py b/tests/bot/test_pagination.py
new file mode 100644
index 000000000..0a734b505
--- /dev/null
+++ b/tests/bot/test_pagination.py
@@ -0,0 +1,36 @@
+from unittest import TestCase
+
+from bot import pagination
+
+
+class LinePaginatorTests(TestCase):
+    """Tests functionality of the `LinePaginator`."""
+
+    def setUp(self):
+        """Create a paginator for the test method."""
+        self.paginator = pagination.LinePaginator(prefix='', suffix='', max_size=30)
+
+    def test_add_line_raises_on_too_long_lines(self):
+        """`add_line` should raise a `RuntimeError` for too long lines."""
+        message = f"Line exceeds maximum page size {self.paginator.max_size - 2}"
+        with self.assertRaises(RuntimeError, msg=message):
+            self.paginator.add_line('x' * self.paginator.max_size)
+
+    def test_add_line_works_on_small_lines(self):
+        """`add_line` should allow small lines to be added."""
+        self.paginator.add_line('x' * (self.paginator.max_size - 3))
+
+
+class ImagePaginatorTests(TestCase):
+    """Tests functionality of the `ImagePaginator`."""
+
+    def setUp(self):
+        """Create a paginator for the test method."""
+        self.paginator = pagination.ImagePaginator()
+
+    def test_add_image_appends_image(self):
+        """`add_image` appends the image to the image list."""
+        image = 'lemon'
+        self.paginator.add_image(image)
+
+        assert self.paginator.images == [image]
diff --git a/tests/bot/utils/__init__.py b/tests/bot/utils/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/bot/utils/__init__.py
diff --git a/tests/bot/utils/test_checks.py b/tests/bot/utils/test_checks.py
new file mode 100644
index 000000000..19b758336
--- /dev/null
+++ b/tests/bot/utils/test_checks.py
@@ -0,0 +1,51 @@
+import unittest
+
+from bot.utils import checks
+from tests.helpers import MockContext, MockRole
+
+
+class ChecksTests(unittest.TestCase):
+    """Tests the check functions defined in `bot.checks`."""
+
+    def setUp(self):
+        self.ctx = MockContext()
+
+    def test_with_role_check_without_guild(self):
+        """`with_role_check` returns `False` if `Context.guild` is None."""
+        self.ctx.guild = None
+        self.assertFalse(checks.with_role_check(self.ctx))
+
+    def test_with_role_check_without_required_roles(self):
+        """`with_role_check` returns `False` if `Context.author` lacks the required role."""
+        self.ctx.author.roles = []
+        self.assertFalse(checks.with_role_check(self.ctx))
+
+    def test_with_role_check_with_guild_and_required_role(self):
+        """`with_role_check` returns `True` if `Context.author` has the required role."""
+        self.ctx.author.roles.append(MockRole(role_id=10))
+        self.assertTrue(checks.with_role_check(self.ctx, 10))
+
+    def test_without_role_check_without_guild(self):
+        """`without_role_check` should return `False` when `Context.guild` is None."""
+        self.ctx.guild = None
+        self.assertFalse(checks.without_role_check(self.ctx))
+
+    def test_without_role_check_returns_false_with_unwanted_role(self):
+        """`without_role_check` returns `False` if `Context.author` has unwanted role."""
+        role_id = 42
+        self.ctx.author.roles.append(MockRole(role_id=role_id))
+        self.assertFalse(checks.without_role_check(self.ctx, role_id))
+
+    def test_without_role_check_returns_true_without_unwanted_role(self):
+        """`without_role_check` returns `True` if `Context.author` does not have unwanted role."""
+        role_id = 42
+        self.ctx.author.roles.append(MockRole(role_id=role_id))
+        self.assertTrue(checks.without_role_check(self.ctx, role_id + 10))
+
+    def test_in_channel_check_for_correct_channel(self):
+        self.ctx.channel.id = 42
+        self.assertTrue(checks.in_channel_check(self.ctx, *[42]))
+
+    def test_in_channel_check_for_incorrect_channel(self):
+        self.ctx.channel.id = 42 + 10
+        self.assertFalse(checks.in_channel_check(self.ctx, *[42]))