Merge branch 'main' into master

10 files changed, 650 insertions, 31 deletions

diff --git a/tests/README.md b/tests/README.md
index 4f62edd68..092324123 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -114,7 +114,7 @@ class BotCogTests(unittest.TestCase):
 
 ### Mocking coroutines
 
-By default, the `unittest.mock.Mock` and `unittest.mock.MagicMock` classes cannot mock coroutines, since the `__call__` method they provide is synchronous. In anticipation of the `AsyncMock` that will be [introduced in Python 3.8](https://docs.python.org/3.9/whatsnew/3.8.html#unittest), we have added an `AsyncMock` helper to [`helpers.py`](/tests/helpers.py). Do note that this drop-in replacement only implements an asynchronous `__call__` method, not the additional assertions that will come with the new `AsyncMock` type in Python 3.8.
+By default, the `unittest.mock.Mock` and `unittest.mock.MagicMock` classes cannot mock coroutines, since the `__call__` method they provide is synchronous. The [`AsyncMock`](https://docs.python.org/3/library/unittest.mock.html#unittest.mock.AsyncMock) that has been [introduced in Python 3.8](https://docs.python.org/3.9/whatsnew/3.8.html#unittest) is an asynchronous version of `MagicMock` that can be used anywhere a coroutine is expected.
 
 ### Special mocks for some `discord.py` types
 
diff --git a/tests/bot/exts/backend/test_error_handler.py b/tests/bot/exts/backend/test_error_handler.py
new file mode 100644
index 000000000..bd4fb5942
--- /dev/null
+++ b/tests/bot/exts/backend/test_error_handler.py
@@ -0,0 +1,550 @@
+import unittest
+from unittest.mock import AsyncMock, MagicMock, call, patch
+
+from discord.ext.commands import errors
+
+from bot.api import ResponseCodeError
+from bot.errors import InvalidInfractedUser, LockedResourceError
+from bot.exts.backend.error_handler import ErrorHandler, setup
+from bot.exts.info.tags import Tags
+from bot.exts.moderation.silence import Silence
+from bot.utils.checks import InWhitelistCheckFailure
+from tests.helpers import MockBot, MockContext, MockGuild, MockRole
+
+
+class ErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
+    """Tests for error handler functionality."""
+
+    def setUp(self):
+        self.bot = MockBot()
+        self.ctx = MockContext(bot=self.bot)
+
+    async def test_error_handler_already_handled(self):
+        """Should not do anything when error is already handled by local error handler."""
+        self.ctx.reset_mock()
+        cog = ErrorHandler(self.bot)
+        error = errors.CommandError()
+        error.handled = "foo"
+        self.assertIsNone(await cog.on_command_error(self.ctx, error))
+        self.ctx.send.assert_not_awaited()
+
+    async def test_error_handler_command_not_found_error_not_invoked_by_handler(self):
+        """Should try first (un)silence channel, when fail, try to get tag."""
+        error = errors.CommandNotFound()
+        test_cases = (
+            {
+                "try_silence_return": True,
+                "called_try_get_tag": False
+            },
+            {
+                "try_silence_return": False,
+                "called_try_get_tag": False
+            },
+            {
+                "try_silence_return": False,
+                "called_try_get_tag": True
+            }
+        )
+        cog = ErrorHandler(self.bot)
+        cog.try_silence = AsyncMock()
+        cog.try_get_tag = AsyncMock()
+
+        for case in test_cases:
+            with self.subTest(try_silence_return=case["try_silence_return"], try_get_tag=case["called_try_get_tag"]):
+                self.ctx.reset_mock()
+                cog.try_silence.reset_mock(return_value=True)
+                cog.try_get_tag.reset_mock()
+
+                cog.try_silence.return_value = case["try_silence_return"]
+                self.ctx.channel.id = 1234
+
+                self.assertIsNone(await cog.on_command_error(self.ctx, error))
+
+                if case["try_silence_return"]:
+                    cog.try_get_tag.assert_not_awaited()
+                    cog.try_silence.assert_awaited_once()
+                else:
+                    cog.try_silence.assert_awaited_once()
+                    cog.try_get_tag.assert_awaited_once()
+
+                self.ctx.send.assert_not_awaited()
+
+    async def test_error_handler_command_not_found_error_invoked_by_handler(self):
+        """Should do nothing when error is `CommandNotFound` and have attribute `invoked_from_error_handler`."""
+        ctx = MockContext(bot=self.bot, invoked_from_error_handler=True)
+
+        cog = ErrorHandler(self.bot)
+        cog.try_silence = AsyncMock()
+        cog.try_get_tag = AsyncMock()
+
+        error = errors.CommandNotFound()
+
+        self.assertIsNone(await cog.on_command_error(ctx, error))
+
+        cog.try_silence.assert_not_awaited()
+        cog.try_get_tag.assert_not_awaited()
+        self.ctx.send.assert_not_awaited()
+
+    async def test_error_handler_user_input_error(self):
+        """Should await `ErrorHandler.handle_user_input_error` when error is `UserInputError`."""
+        self.ctx.reset_mock()
+        cog = ErrorHandler(self.bot)
+        cog.handle_user_input_error = AsyncMock()
+        error = errors.UserInputError()
+        self.assertIsNone(await cog.on_command_error(self.ctx, error))
+        cog.handle_user_input_error.assert_awaited_once_with(self.ctx, error)
+
+    async def test_error_handler_check_failure(self):
+        """Should await `ErrorHandler.handle_check_failure` when error is `CheckFailure`."""
+        self.ctx.reset_mock()
+        cog = ErrorHandler(self.bot)
+        cog.handle_check_failure = AsyncMock()
+        error = errors.CheckFailure()
+        self.assertIsNone(await cog.on_command_error(self.ctx, error))
+        cog.handle_check_failure.assert_awaited_once_with(self.ctx, error)
+
+    async def test_error_handler_command_on_cooldown(self):
+        """Should send error with `ctx.send` when error is `CommandOnCooldown`."""
+        self.ctx.reset_mock()
+        cog = ErrorHandler(self.bot)
+        error = errors.CommandOnCooldown(10, 9)
+        self.assertIsNone(await cog.on_command_error(self.ctx, error))
+        self.ctx.send.assert_awaited_once_with(error)
+
+    async def test_error_handler_command_invoke_error(self):
+        """Should call `handle_api_error` or `handle_unexpected_error` depending on original error."""
+        cog = ErrorHandler(self.bot)
+        cog.handle_api_error = AsyncMock()
+        cog.handle_unexpected_error = AsyncMock()
+        test_cases = (
+            {
+                "args": (self.ctx, errors.CommandInvokeError(ResponseCodeError(AsyncMock()))),
+                "expect_mock_call": cog.handle_api_error
+            },
+            {
+                "args": (self.ctx, errors.CommandInvokeError(TypeError)),
+                "expect_mock_call": cog.handle_unexpected_error
+            },
+            {
+                "args": (self.ctx, errors.CommandInvokeError(LockedResourceError("abc", "test"))),
+                "expect_mock_call": "send"
+            },
+            {
+                "args": (self.ctx, errors.CommandInvokeError(InvalidInfractedUser(self.ctx.author))),
+                "expect_mock_call": "send"
+            }
+        )
+
+        for case in test_cases:
+            with self.subTest(args=case["args"], expect_mock_call=case["expect_mock_call"]):
+                self.ctx.send.reset_mock()
+                self.assertIsNone(await cog.on_command_error(*case["args"]))
+                if case["expect_mock_call"] == "send":
+                    self.ctx.send.assert_awaited_once()
+                else:
+                    case["expect_mock_call"].assert_awaited_once_with(
+                        self.ctx, case["args"][1].original
+                    )
+
+    async def test_error_handler_conversion_error(self):
+        """Should call `handle_api_error` or `handle_unexpected_error` depending on original error."""
+        cog = ErrorHandler(self.bot)
+        cog.handle_api_error = AsyncMock()
+        cog.handle_unexpected_error = AsyncMock()
+        cases = (
+            {
+                "error": errors.ConversionError(AsyncMock(), ResponseCodeError(AsyncMock())),
+                "mock_function_to_call": cog.handle_api_error
+            },
+            {
+                "error": errors.ConversionError(AsyncMock(), TypeError),
+                "mock_function_to_call": cog.handle_unexpected_error
+            }
+        )
+
+        for case in cases:
+            with self.subTest(**case):
+                self.assertIsNone(await cog.on_command_error(self.ctx, case["error"]))
+                case["mock_function_to_call"].assert_awaited_once_with(self.ctx, case["error"].original)
+
+    async def test_error_handler_two_other_errors(self):
+        """Should call `handle_unexpected_error` if error is `MaxConcurrencyReached` or `ExtensionError`."""
+        cog = ErrorHandler(self.bot)
+        cog.handle_unexpected_error = AsyncMock()
+        errs = (
+            errors.MaxConcurrencyReached(1, MagicMock()),
+            errors.ExtensionError(name="foo")
+        )
+
+        for err in errs:
+            with self.subTest(error=err):
+                cog.handle_unexpected_error.reset_mock()
+                self.assertIsNone(await cog.on_command_error(self.ctx, err))
+                cog.handle_unexpected_error.assert_awaited_once_with(self.ctx, err)
+
+    @patch("bot.exts.backend.error_handler.log")
+    async def test_error_handler_other_errors(self, log_mock):
+        """Should `log.debug` other errors."""
+        cog = ErrorHandler(self.bot)
+        error = errors.DisabledCommand()  # Use this just as a other error
+        self.assertIsNone(await cog.on_command_error(self.ctx, error))
+        log_mock.debug.assert_called_once()
+
+
+class TrySilenceTests(unittest.IsolatedAsyncioTestCase):
+    """Test for helper functions that handle `CommandNotFound` error."""
+
+    def setUp(self):
+        self.bot = MockBot()
+        self.silence = Silence(self.bot)
+        self.bot.get_command.return_value = self.silence.silence
+        self.ctx = MockContext(bot=self.bot)
+        self.cog = ErrorHandler(self.bot)
+
+    async def test_try_silence_context_invoked_from_error_handler(self):
+        """Should set `Context.invoked_from_error_handler` to `True`."""
+        self.ctx.invoked_with = "foo"
+        await self.cog.try_silence(self.ctx)
+        self.assertTrue(hasattr(self.ctx, "invoked_from_error_handler"))
+        self.assertTrue(self.ctx.invoked_from_error_handler)
+
+    async def test_try_silence_get_command(self):
+        """Should call `get_command` with `silence`."""
+        self.ctx.invoked_with = "foo"
+        await self.cog.try_silence(self.ctx)
+        self.bot.get_command.assert_called_once_with("silence")
+
+    async def test_try_silence_no_permissions_to_run(self):
+        """Should return `False` because missing permissions."""
+        self.ctx.invoked_with = "foo"
+        self.bot.get_command.return_value.can_run = AsyncMock(return_value=False)
+        self.assertFalse(await self.cog.try_silence(self.ctx))
+
+    async def test_try_silence_no_permissions_to_run_command_error(self):
+        """Should return `False` because `CommandError` raised (no permissions)."""
+        self.ctx.invoked_with = "foo"
+        self.bot.get_command.return_value.can_run = AsyncMock(side_effect=errors.CommandError())
+        self.assertFalse(await self.cog.try_silence(self.ctx))
+
+    async def test_try_silence_silencing(self):
+        """Should run silence command with correct arguments."""
+        self.bot.get_command.return_value.can_run = AsyncMock(return_value=True)
+        test_cases = ("shh", "shhh", "shhhhhh", "shhhhhhhhhhhhhhhhhhh")
+
+        for case in test_cases:
+            with self.subTest(message=case):
+                self.ctx.reset_mock()
+                self.ctx.invoked_with = case
+                self.assertTrue(await self.cog.try_silence(self.ctx))
+                self.ctx.invoke.assert_awaited_once_with(
+                    self.bot.get_command.return_value,
+                    duration=min(case.count("h")*2, 15)
+                )
+
+    async def test_try_silence_unsilence(self):
+        """Should call unsilence command."""
+        self.silence.silence.can_run = AsyncMock(return_value=True)
+        test_cases = ("unshh", "unshhhhh", "unshhhhhhhhh")
+
+        for case in test_cases:
+            with self.subTest(message=case):
+                self.bot.get_command.side_effect = (self.silence.silence, self.silence.unsilence)
+                self.ctx.reset_mock()
+                self.ctx.invoked_with = case
+                self.assertTrue(await self.cog.try_silence(self.ctx))
+                self.ctx.invoke.assert_awaited_once_with(self.silence.unsilence)
+
+    async def test_try_silence_no_match(self):
+        """Should return `False` when message don't match."""
+        self.ctx.invoked_with = "foo"
+        self.assertFalse(await self.cog.try_silence(self.ctx))
+
+
+class TryGetTagTests(unittest.IsolatedAsyncioTestCase):
+    """Tests for `try_get_tag` function."""
+
+    def setUp(self):
+        self.bot = MockBot()
+        self.ctx = MockContext()
+        self.tag = Tags(self.bot)
+        self.cog = ErrorHandler(self.bot)
+        self.bot.get_command.return_value = self.tag.get_command
+
+    async def test_try_get_tag_get_command(self):
+        """Should call `Bot.get_command` with `tags get` argument."""
+        self.bot.get_command.reset_mock()
+        self.ctx.invoked_with = "foo"
+        await self.cog.try_get_tag(self.ctx)
+        self.bot.get_command.assert_called_once_with("tags get")
+
+    async def test_try_get_tag_invoked_from_error_handler(self):
+        """`self.ctx` should have `invoked_from_error_handler` `True`."""
+        self.ctx.invoked_from_error_handler = False
+        self.ctx.invoked_with = "foo"
+        await self.cog.try_get_tag(self.ctx)
+        self.assertTrue(self.ctx.invoked_from_error_handler)
+
+    async def test_try_get_tag_no_permissions(self):
+        """Test how to handle checks failing."""
+        self.tag.get_command.can_run = AsyncMock(return_value=False)
+        self.ctx.invoked_with = "foo"
+        self.assertIsNone(await self.cog.try_get_tag(self.ctx))
+
+    async def test_try_get_tag_command_error(self):
+        """Should call `on_command_error` when `CommandError` raised."""
+        err = errors.CommandError()
+        self.tag.get_command.can_run = AsyncMock(side_effect=err)
+        self.cog.on_command_error = AsyncMock()
+        self.ctx.invoked_with = "foo"
+        self.assertIsNone(await self.cog.try_get_tag(self.ctx))
+        self.cog.on_command_error.assert_awaited_once_with(self.ctx, err)
+
+    @patch("bot.exts.backend.error_handler.TagNameConverter")
+    async def test_try_get_tag_convert_success(self, tag_converter):
+        """Converting tag should successful."""
+        self.ctx.invoked_with = "foo"
+        tag_converter.convert = AsyncMock(return_value="foo")
+        self.assertIsNone(await self.cog.try_get_tag(self.ctx))
+        tag_converter.convert.assert_awaited_once_with(self.ctx, "foo")
+        self.ctx.invoke.assert_awaited_once()
+
+    @patch("bot.exts.backend.error_handler.TagNameConverter")
+    async def test_try_get_tag_convert_fail(self, tag_converter):
+        """Converting tag should raise `BadArgument`."""
+        self.ctx.reset_mock()
+        self.ctx.invoked_with = "bar"
+        tag_converter.convert = AsyncMock(side_effect=errors.BadArgument())
+        self.assertIsNone(await self.cog.try_get_tag(self.ctx))
+        self.ctx.invoke.assert_not_awaited()
+
+    async def test_try_get_tag_ctx_invoke(self):
+        """Should call `ctx.invoke` with proper args/kwargs."""
+        self.ctx.reset_mock()
+        self.ctx.invoked_with = "foo"
+        self.assertIsNone(await self.cog.try_get_tag(self.ctx))
+        self.ctx.invoke.assert_awaited_once_with(self.tag.get_command, tag_name="foo")
+
+    async def test_dont_call_suggestion_tag_sent(self):
+        """Should never call command suggestion if tag is already sent."""
+        self.ctx.invoked_with = "foo"
+        self.ctx.invoke = AsyncMock(return_value=True)
+        self.cog.send_command_suggestion = AsyncMock()
+
+        await self.cog.try_get_tag(self.ctx)
+        self.cog.send_command_suggestion.assert_not_awaited()
+
+    @patch("bot.exts.backend.error_handler.MODERATION_ROLES", new=[1234])
+    async def test_dont_call_suggestion_if_user_mod(self):
+        """Should not call command suggestion if user is a mod."""
+        self.ctx.invoked_with = "foo"
+        self.ctx.invoke = AsyncMock(return_value=False)
+        self.ctx.author.roles = [MockRole(id=1234)]
+        self.cog.send_command_suggestion = AsyncMock()
+
+        await self.cog.try_get_tag(self.ctx)
+        self.cog.send_command_suggestion.assert_not_awaited()
+
+    async def test_call_suggestion(self):
+        """Should call command suggestion if user is not a mod."""
+        self.ctx.invoked_with = "foo"
+        self.ctx.invoke = AsyncMock(return_value=False)
+        self.cog.send_command_suggestion = AsyncMock()
+
+        await self.cog.try_get_tag(self.ctx)
+        self.cog.send_command_suggestion.assert_awaited_once_with(self.ctx, "foo")
+
+
+class IndividualErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
+    """Individual error categories handler tests."""
+
+    def setUp(self):
+        self.bot = MockBot()
+        self.ctx = MockContext(bot=self.bot)
+        self.cog = ErrorHandler(self.bot)
+
+    async def test_handle_input_error_handler_errors(self):
+        """Should handle each error probably."""
+        test_cases = (
+            {
+                "error": errors.MissingRequiredArgument(MagicMock()),
+                "call_prepared": True
+            },
+            {
+                "error": errors.TooManyArguments(),
+                "call_prepared": True
+            },
+            {
+                "error": errors.BadArgument(),
+                "call_prepared": True
+            },
+            {
+                "error": errors.BadUnionArgument(MagicMock(), MagicMock(), MagicMock()),
+                "call_prepared": True
+            },
+            {
+                "error": errors.ArgumentParsingError(),
+                "call_prepared": False
+            },
+            {
+                "error": errors.UserInputError(),
+                "call_prepared": True
+            }
+        )
+
+        for case in test_cases:
+            with self.subTest(error=case["error"], call_prepared=case["call_prepared"]):
+                self.ctx.reset_mock()
+                self.assertIsNone(await self.cog.handle_user_input_error(self.ctx, case["error"]))
+                self.ctx.send.assert_awaited_once()
+                if case["call_prepared"]:
+                    self.ctx.send_help.assert_awaited_once()
+                else:
+                    self.ctx.send_help.assert_not_awaited()
+
+    async def test_handle_check_failure_errors(self):
+        """Should await `ctx.send` when error is check failure."""
+        test_cases = (
+            {
+                "error": errors.BotMissingPermissions(MagicMock()),
+                "call_ctx_send": True
+            },
+            {
+                "error": errors.BotMissingRole(MagicMock()),
+                "call_ctx_send": True
+            },
+            {
+                "error": errors.BotMissingAnyRole(MagicMock()),
+                "call_ctx_send": True
+            },
+            {
+                "error": errors.NoPrivateMessage(),
+                "call_ctx_send": True
+            },
+            {
+                "error": InWhitelistCheckFailure(1234),
+                "call_ctx_send": True
+            },
+            {
+                "error": ResponseCodeError(MagicMock()),
+                "call_ctx_send": False
+            }
+        )
+
+        for case in test_cases:
+            with self.subTest(error=case["error"], call_ctx_send=case["call_ctx_send"]):
+                self.ctx.reset_mock()
+                await self.cog.handle_check_failure(self.ctx, case["error"])
+                if case["call_ctx_send"]:
+                    self.ctx.send.assert_awaited_once()
+                else:
+                    self.ctx.send.assert_not_awaited()
+
+    @patch("bot.exts.backend.error_handler.log")
+    async def test_handle_api_error(self, log_mock):
+        """Should `ctx.send` on HTTP error codes, `log.debug|warning` depends on code."""
+        test_cases = (
+            {
+                "error": ResponseCodeError(AsyncMock(status=400)),
+                "log_level": "debug"
+            },
+            {
+                "error": ResponseCodeError(AsyncMock(status=404)),
+                "log_level": "debug"
+            },
+            {
+                "error": ResponseCodeError(AsyncMock(status=550)),
+                "log_level": "warning"
+            },
+            {
+                "error": ResponseCodeError(AsyncMock(status=1000)),
+                "log_level": "warning"
+            }
+        )
+
+        for case in test_cases:
+            with self.subTest(error=case["error"], log_level=case["log_level"]):
+                self.ctx.reset_mock()
+                log_mock.reset_mock()
+                await self.cog.handle_api_error(self.ctx, case["error"])
+                self.ctx.send.assert_awaited_once()
+                if case["log_level"] == "warning":
+                    log_mock.warning.assert_called_once()
+                else:
+                    log_mock.debug.assert_called_once()
+
+    @patch("bot.exts.backend.error_handler.push_scope")
+    @patch("bot.exts.backend.error_handler.log")
+    async def test_handle_unexpected_error(self, log_mock, push_scope_mock):
+        """Should `ctx.send` this error, error log this and sent to Sentry."""
+        for case in (None, MockGuild()):
+            with self.subTest(guild=case):
+                self.ctx.reset_mock()
+                log_mock.reset_mock()
+                push_scope_mock.reset_mock()
+
+                self.ctx.guild = case
+                await self.cog.handle_unexpected_error(self.ctx, errors.CommandError())
+
+                self.ctx.send.assert_awaited_once()
+                log_mock.error.assert_called_once()
+                push_scope_mock.assert_called_once()
+
+                set_tag_calls = [
+                    call("command", self.ctx.command.qualified_name),
+                    call("message_id", self.ctx.message.id),
+                    call("channel_id", self.ctx.channel.id),
+                ]
+                set_extra_calls = [
+                    call("full_message", self.ctx.message.content)
+                ]
+                if case:
+                    url = (
+                        f"https://discordapp.com/channels/"
+                        f"{self.ctx.guild.id}/{self.ctx.channel.id}/{self.ctx.message.id}"
+                    )
+                    set_extra_calls.append(call("jump_to", url))
+
+                push_scope_mock.set_tag.has_calls(set_tag_calls)
+                push_scope_mock.set_extra.has_calls(set_extra_calls)
+
+
+class OtherErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
+    """Other `ErrorHandler` tests."""
+
+    def setUp(self):
+        self.bot = MockBot()
+        self.ctx = MockContext()
+
+    async def test_get_help_command_command_specified(self):
+        """Should return coroutine of help command of specified command."""
+        self.ctx.command = "foo"
+        result = ErrorHandler.get_help_command(self.ctx)
+        expected = self.ctx.send_help("foo")
+        self.assertEqual(result.__qualname__, expected.__qualname__)
+        self.assertEqual(result.cr_frame.f_locals, expected.cr_frame.f_locals)
+
+        # Await coroutines to avoid warnings
+        await result
+        await expected
+
+    async def test_get_help_command_no_command_specified(self):
+        """Should return coroutine of help command."""
+        self.ctx.command = None
+        result = ErrorHandler.get_help_command(self.ctx)
+        expected = self.ctx.send_help()
+        self.assertEqual(result.__qualname__, expected.__qualname__)
+        self.assertEqual(result.cr_frame.f_locals, expected.cr_frame.f_locals)
+
+        # Await coroutines to avoid warnings
+        await result
+        await expected
+
+
+class ErrorHandlerSetupTests(unittest.TestCase):
+    """Tests for `ErrorHandler` `setup` function."""
+
+    def test_setup(self):
+        """Should call `bot.add_cog` with `ErrorHandler`."""
+        bot = MockBot()
+        setup(bot)
+        bot.add_cog.assert_called_once()
diff --git a/tests/bot/exts/info/doc/__init__.py b/tests/bot/exts/info/doc/__init__.py
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/bot/exts/info/doc/__init__.py
diff --git a/tests/bot/exts/info/doc/test_parsing.py b/tests/bot/exts/info/doc/test_parsing.py
new file mode 100644
index 000000000..1663d8491
--- /dev/null
+++ b/tests/bot/exts/info/doc/test_parsing.py
@@ -0,0 +1,66 @@
+from unittest import TestCase
+
+from bot.exts.info.doc import _parsing as parsing
+
+
+class SignatureSplitter(TestCase):
+
+    def test_basic_split(self):
+        test_cases = (
+            ("0,0,0", ["0", "0", "0"]),
+            ("0,a=0,a=0", ["0", "a=0", "a=0"]),
+        )
+        self._run_tests(test_cases)
+
+    def test_commas_ignored_in_brackets(self):
+        test_cases = (
+            ("0,[0,0],0,[0,0],0", ["0", "[0,0]", "0", "[0,0]", "0"]),
+            ("(0,),0,(0,(0,),0),0", ["(0,)", "0", "(0,(0,),0)", "0"]),
+        )
+        self._run_tests(test_cases)
+
+    def test_mixed_brackets(self):
+        tests_cases = (
+            ("[0,{0},0],0,{0:0},0", ["[0,{0},0]", "0", "{0:0}", "0"]),
+            ("([0],0,0),0,(0,0),0", ["([0],0,0)", "0", "(0,0)", "0"]),
+            ("([(0,),(0,)],0),0", ["([(0,),(0,)],0)", "0"]),
+        )
+        self._run_tests(tests_cases)
+
+    def test_string_contents_ignored(self):
+        test_cases = (
+            ("'0,0',0,',',0", ["'0,0'", "0", "','", "0"]),
+            ("0,[']',0],0", ["0", "[']',0]", "0"]),
+            ("{0,0,'}}',0,'{'},0", ["{0,0,'}}',0,'{'}", "0"]),
+        )
+        self._run_tests(test_cases)
+
+    def test_mixed_quotes(self):
+        test_cases = (
+            ("\"0',0',\",'0,0',0", ["\"0',0',\"", "'0,0'", "0"]),
+            ("\",',\",'\",',0", ["\",',\"", "'\",'", "0"]),
+        )
+        self._run_tests(test_cases)
+
+    def test_quote_escaped(self):
+        test_cases = (
+            (r"'\',','\\',0", [r"'\','", r"'\\'", "0"]),
+            (r"'0\',0\\\'\\',0", [r"'0\',0\\\'\\'", "0"]),
+        )
+        self._run_tests(test_cases)
+
+    def test_real_signatures(self):
+        test_cases = (
+            ("start, stop[, step]", ["start", " stop[, step]"]),
+            ("object=b'', encoding='utf-8', errors='strict'", ["object=b''", " encoding='utf-8'", " errors='strict'"]),
+            (
+                "typename, field_names, *, rename=False, defaults=None, module=None",
+                ["typename", " field_names", " *", " rename=False", " defaults=None", " module=None"]
+            ),
+        )
+        self._run_tests(test_cases)
+
+    def _run_tests(self, test_cases):
+        for input_string, expected_output in test_cases:
+            with self.subTest(input_string=input_string):
+                self.assertEqual(list(parsing._split_parameters(input_string)), expected_output)
diff --git a/tests/bot/exts/info/test_information.py b/tests/bot/exts/info/test_information.py
index 80731c9f0..770660fe3 100644
--- a/tests/bot/exts/info/test_information.py
+++ b/tests/bot/exts/info/test_information.py
@@ -281,8 +281,10 @@ class UserEmbedTests(unittest.IsolatedAsyncioTestCase):
         """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))
         user = helpers.MockMember()
+        user.public_flags = unittest.mock.MagicMock(verified_bot=False)
         user.nick = None
         user.__str__ = unittest.mock.Mock(return_value="Mr. Hemlock")
+        user.colour = 0
 
         embed = await self.cog.create_user_embed(ctx, user)
 
@@ -296,8 +298,10 @@ class UserEmbedTests(unittest.IsolatedAsyncioTestCase):
         """The embed should use the nick if it's available."""
         ctx = helpers.MockContext(channel=helpers.MockTextChannel(id=1))
         user = helpers.MockMember()
+        user.public_flags = unittest.mock.MagicMock(verified_bot=False)
         user.nick = "Cat lover"
         user.__str__ = unittest.mock.Mock(return_value="Mr. Hemlock")
+        user.colour = 0
 
         embed = await self.cog.create_user_embed(ctx, user)
 
@@ -311,10 +315,9 @@ class UserEmbedTests(unittest.IsolatedAsyncioTestCase):
         """Created `!user` embeds should not contain mention of the @everyone-role."""
         ctx = helpers.MockContext(channel=helpers.MockTextChannel(id=1))
         admins_role = helpers.MockRole(name='Admins')
-        admins_role.colour = 100
 
         # A `MockMember` has the @Everyone role by default; we add the Admins to that.
-        user = helpers.MockMember(roles=[admins_role], top_role=admins_role)
+        user = helpers.MockMember(roles=[admins_role], colour=100)
 
         embed = await self.cog.create_user_embed(ctx, user)
 
@@ -332,12 +335,11 @@ class UserEmbedTests(unittest.IsolatedAsyncioTestCase):
         ctx = helpers.MockContext(channel=helpers.MockTextChannel(id=50))
 
         moderators_role = helpers.MockRole(name='Moderators')
-        moderators_role.colour = 100
 
         infraction_counts.return_value = ("Infractions", "expanded infractions info")
         nomination_counts.return_value = ("Nominations", "nomination info")
 
-        user = helpers.MockMember(id=314, roles=[moderators_role], top_role=moderators_role)
+        user = helpers.MockMember(id=314, roles=[moderators_role], colour=100)
         embed = await self.cog.create_user_embed(ctx, user)
 
         infraction_counts.assert_called_once_with(user)
@@ -367,11 +369,10 @@ class UserEmbedTests(unittest.IsolatedAsyncioTestCase):
         ctx = helpers.MockContext(channel=helpers.MockTextChannel(id=100))
 
         moderators_role = helpers.MockRole(name='Moderators')
-        moderators_role.colour = 100
 
         infraction_counts.return_value = ("Infractions", "basic infractions info")
 
-        user = helpers.MockMember(id=314, roles=[moderators_role], top_role=moderators_role)
+        user = helpers.MockMember(id=314, roles=[moderators_role], colour=100)
         embed = await self.cog.create_user_embed(ctx, user)
 
         infraction_counts.assert_called_once_with(user)
@@ -407,12 +408,11 @@ class UserEmbedTests(unittest.IsolatedAsyncioTestCase):
         ctx = helpers.MockContext()
 
         moderators_role = helpers.MockRole(name='Moderators')
-        moderators_role.colour = 100
 
-        user = helpers.MockMember(id=314, roles=[moderators_role], top_role=moderators_role)
+        user = helpers.MockMember(id=314, roles=[moderators_role], colour=100)
         embed = await self.cog.create_user_embed(ctx, user)
 
-        self.assertEqual(embed.colour, discord.Colour(moderators_role.colour))
+        self.assertEqual(embed.colour, discord.Colour(100))
 
     @unittest.mock.patch(
         f"{COG_PATH}.basic_user_infraction_counts",
@@ -422,7 +422,7 @@ class UserEmbedTests(unittest.IsolatedAsyncioTestCase):
         """The embed should be created with a blurple colour if the user has no assigned roles."""
         ctx = helpers.MockContext()
 
-        user = helpers.MockMember(id=217)
+        user = helpers.MockMember(id=217, colour=discord.Colour.default())
         embed = await self.cog.create_user_embed(ctx, user)
 
         self.assertEqual(embed.colour, discord.Colour.blurple())
@@ -435,7 +435,7 @@ class UserEmbedTests(unittest.IsolatedAsyncioTestCase):
         """The embed thumbnail should be set to the user's avatar in `png` format."""
         ctx = helpers.MockContext()
 
-        user = helpers.MockMember(id=217)
+        user = helpers.MockMember(id=217, colour=0)
         user.avatar_url_as.return_value = "avatar url"
         embed = await self.cog.create_user_embed(ctx, user)
 
diff --git a/tests/bot/exts/moderation/infraction/test_infractions.py b/tests/bot/exts/moderation/infraction/test_infractions.py
index 86c2617ea..08f39cd50 100644
--- a/tests/bot/exts/moderation/infraction/test_infractions.py
+++ b/tests/bot/exts/moderation/infraction/test_infractions.py
@@ -39,7 +39,7 @@ class TruncationTests(unittest.IsolatedAsyncioTestCase):
             delete_message_days=0
         )
         self.cog.apply_infraction.assert_awaited_once_with(
-            self.ctx, {"foo": "bar"}, self.target, self.ctx.guild.ban.return_value
+            self.ctx, {"foo": "bar", "purge": ""}, self.target, self.ctx.guild.ban.return_value
         )
 
     @patch("bot.exts.moderation.infraction._utils.post_infraction")
diff --git a/tests/bot/exts/moderation/infraction/test_utils.py b/tests/bot/exts/moderation/infraction/test_utils.py
index 5b62463e0..ee9ff650c 100644
--- a/tests/bot/exts/moderation/infraction/test_utils.py
+++ b/tests/bot/exts/moderation/infraction/test_utils.py
@@ -146,7 +146,7 @@ class ModerationUtilsTests(unittest.IsolatedAsyncioTestCase):
                     name=utils.INFRACTION_AUTHOR_NAME,
                     url=utils.RULES_URL,
                     icon_url=Icons.token_removed
-                ).set_footer(text=utils.INFRACTION_APPEAL_FOOTER),
+                ).set_footer(text=utils.INFRACTION_APPEAL_MODMAIL_FOOTER),
                 "send_result": True
             },
             {
@@ -164,9 +164,11 @@ class ModerationUtilsTests(unittest.IsolatedAsyncioTestCase):
                     name=utils.INFRACTION_AUTHOR_NAME,
                     url=utils.RULES_URL,
                     icon_url=Icons.token_removed
-                ),
+                ).set_footer(text=utils.INFRACTION_APPEAL_MODMAIL_FOOTER),
                 "send_result": False
             },
+            # Note that this test case asserts that the DM that *would* get sent to the user is formatted
+            # correctly, even though that message is deliberately never sent.
             {
                 "args": (self.user, "note", None, None, Icons.defcon_denied),
                 "expected_output": Embed(
@@ -182,7 +184,7 @@ class ModerationUtilsTests(unittest.IsolatedAsyncioTestCase):
                     name=utils.INFRACTION_AUTHOR_NAME,
                     url=utils.RULES_URL,
                     icon_url=Icons.defcon_denied
-                ),
+                ).set_footer(text=utils.INFRACTION_APPEAL_MODMAIL_FOOTER),
                 "send_result": False
             },
             {
@@ -200,7 +202,7 @@ class ModerationUtilsTests(unittest.IsolatedAsyncioTestCase):
                     name=utils.INFRACTION_AUTHOR_NAME,
                     url=utils.RULES_URL,
                     icon_url=Icons.defcon_denied
-                ).set_footer(text=utils.INFRACTION_APPEAL_FOOTER),
+                ).set_footer(text=utils.INFRACTION_APPEAL_MODMAIL_FOOTER),
                 "send_result": False
             },
             {
@@ -218,7 +220,7 @@ class ModerationUtilsTests(unittest.IsolatedAsyncioTestCase):
                     name=utils.INFRACTION_AUTHOR_NAME,
                     url=utils.RULES_URL,
                     icon_url=Icons.defcon_denied
-                ).set_footer(text=utils.INFRACTION_APPEAL_FOOTER),
+                ).set_footer(text=utils.INFRACTION_APPEAL_MODMAIL_FOOTER),
                 "send_result": True
             }
         ]
diff --git a/tests/bot/test_converters.py b/tests/bot/test_converters.py
index c42111f3f..4af84dde5 100644
--- a/tests/bot/test_converters.py
+++ b/tests/bot/test_converters.py
@@ -10,9 +10,9 @@ from bot.converters import (
     Duration,
     HushDurationConverter,
     ISODateTime,
+    PackageName,
     TagContentConverter,
     TagNameConverter,
-    ValidPythonIdentifier,
 )
 
 
@@ -78,24 +78,23 @@ class ConverterTests(unittest.IsolatedAsyncioTestCase):
                 with self.assertRaisesRegex(BadArgument, re.escape(exception_message)):
                     await TagNameConverter.convert(self.context, invalid_name)
 
-    async def test_valid_python_identifier_for_valid(self):
-        """ValidPythonIdentifier returns valid identifiers unchanged."""
-        test_values = ('foo', 'lemon')
+    async def test_package_name_for_valid(self):
+        """PackageName returns valid package names unchanged."""
+        test_values = ('foo', 'le_mon', 'num83r')
 
         for name in test_values:
             with self.subTest(identifier=name):
-                conversion = await ValidPythonIdentifier.convert(self.context, name)
+                conversion = await PackageName.convert(self.context, name)
                 self.assertEqual(name, conversion)
 
-    async def test_valid_python_identifier_for_invalid(self):
-        """ValidPythonIdentifier raises the proper exception for invalid identifiers."""
-        test_values = ('nested.stuff', '#####')
+    async def test_package_name_for_invalid(self):
+        """PackageName raises the proper exception for invalid package names."""
+        test_values = ('text_with_a_dot.', 'UpperCaseName', 'dashed-name')
 
         for name in test_values:
             with self.subTest(identifier=name):
-                exception_message = f'`{name}` is not a valid Python identifier'
-                with self.assertRaisesRegex(BadArgument, re.escape(exception_message)):
-                    await ValidPythonIdentifier.convert(self.context, name)
+                with self.assertRaises(BadArgument):
+                    await PackageName.convert(self.context, name)
 
     async def test_duration_converter_for_valid(self):
         """Duration returns the correct `datetime` for valid duration strings."""
diff --git a/tests/bot/utils/test_services.py b/tests/bot/utils/test_services.py
index 1b48f6560..3b71022db 100644
--- a/tests/bot/utils/test_services.py
+++ b/tests/bot/utils/test_services.py
@@ -30,9 +30,9 @@ class PasteTests(unittest.IsolatedAsyncioTestCase):
         """Url with specified extension is returned on successful requests."""
         key = "paste_key"
         test_cases = (
-            (f"https://paste_service.com/{key}.txt", "txt"),
+            (f"https://paste_service.com/{key}.txt?noredirect", "txt"),
             (f"https://paste_service.com/{key}.py", "py"),
-            (f"https://paste_service.com/{key}", ""),
+            (f"https://paste_service.com/{key}?noredirect", ""),
         )
         response = MagicMock(
             json=AsyncMock(return_value={"key": key})
diff --git a/tests/helpers.py b/tests/helpers.py
index 496363ae3..e3dc5fe5b 100644
--- a/tests/helpers.py
+++ b/tests/helpers.py
@@ -385,6 +385,7 @@ message_instance = discord.Message(state=state, channel=channel, data=message_da
 
 # Create a Context instance to get a realistic MagicMock of `discord.ext.commands.Context`
 context_instance = Context(message=unittest.mock.MagicMock(), prefix=unittest.mock.MagicMock())
+context_instance.invoked_from_error_handler = None
 
 
 class MockContext(CustomMockMixin, unittest.mock.MagicMock):
@@ -402,6 +403,7 @@ class MockContext(CustomMockMixin, unittest.mock.MagicMock):
         self.guild = kwargs.get('guild', MockGuild())
         self.author = kwargs.get('author', MockMember())
         self.channel = kwargs.get('channel', MockTextChannel())
+        self.invoked_from_error_handler = kwargs.get('invoked_from_error_handler', False)
 
 
 attachment_instance = discord.Attachment(data=unittest.mock.MagicMock(id=1), state=unittest.mock.MagicMock())