Merge branch 'master' into token_and_bad_code

1 files changed, 373 insertions, 11 deletions

diff --git a/tests/helpers.py b/tests/helpers.py
index 2908294f7..8496ba031 100644
--- a/tests/helpers.py
+++ b/tests/helpers.py
@@ -1,23 +1,19 @@
+from __future__ import annotations
+
 import asyncio
 import functools
-from unittest.mock import MagicMock
-
-
-__all__ = ('AsyncMock', 'async_test')
-
+import inspect
+import unittest.mock
+from typing import Any, Iterable, Optional
 
-# TODO: Remove me on 3.8
-class AsyncMock(MagicMock):
-    async def __call__(self, *args, **kwargs):
-        return super(AsyncMock, self).__call__(*args, **kwargs)
+import discord
+from discord.ext.commands import Bot, Context
 
 
 def async_test(wrapped):
     """
     Run a test case via asyncio.
-
     Example:
-
         >>> @async_test
         ... async def lemon_wins():
         ...     assert True
@@ -27,3 +23,369 @@ def async_test(wrapped):
     def wrapper(*args, **kwargs):
         return asyncio.run(wrapped(*args, **kwargs))
     return wrapper
+
+
+class HashableMixin(discord.mixins.EqualityComparable):
+    """
+    Mixin that provides similar hashing and equality functionality as discord.py's `Hashable` mixin.
+
+    Note: discord.py`s `Hashable` mixin bit-shifts `self.id` (`>> 22`); to prevent hash-collisions
+    for the relative small `id` integers we generally use in tests, this bit-shift is omitted.
+    """
+
+    def __hash__(self):
+        return self.id
+
+
+class ColourMixin:
+    """A mixin for Mocks that provides the aliasing of color->colour like discord.py does."""
+
+    @property
+    def color(self) -> discord.Colour:
+        return self.colour
+
+    @color.setter
+    def color(self, color: discord.Colour) -> None:
+        self.colour = color
+
+
+class CustomMockMixin:
+    """
+    Provides common functionality for our custom Mock types.
+
+    The cooperative `__init__` automatically creates `AsyncMock` attributes for every coroutine
+    function `inspect` detects in the `spec` instance we provide. In addition, this mixin takes care
+    of making sure child mocks are instantiated with the correct class. By default, the mock of the
+    children will be `unittest.mock.MagicMock`, but this can be overwritten by setting the attribute
+    `child_mock_type` on the custom mock inheriting from this mixin.
+    """
+
+    child_mock_type = unittest.mock.MagicMock
+
+    def __init__(self, spec: Any = None, **kwargs):
+        super().__init__(spec=spec, **kwargs)
+        if spec:
+            self._extract_coroutine_methods_from_spec_instance(spec)
+
+    def _get_child_mock(self, **kw):
+        """
+        Overwrite of the `_get_child_mock` method to stop the propagation of our custom mock classes.
+
+        Mock objects automatically create children when you access an attribute or call a method on them. By default,
+        the class of these children is the type of the parent itself. However, this would mean that the children created
+        for our custom mock types would also be instances of that custom mock type. This is not desirable, as attributes
+        of, e.g., a `Bot` object are not `Bot` objects themselves. The Python docs for `unittest.mock` hint that
+        overwriting this method is the best way to deal with that.
+
+        This override will look for an attribute called `child_mock_type` and use that as the type of the child mock.
+        """
+        klass = self.child_mock_type
+
+        if self._mock_sealed:
+            attribute = "." + kw["name"] if "name" in kw else "()"
+            mock_name = self._extract_mock_name() + attribute
+            raise AttributeError(mock_name)
+
+        return klass(**kw)
+
+    def _extract_coroutine_methods_from_spec_instance(self, source: Any) -> None:
+        """Automatically detect coroutine functions in `source` and set them as AsyncMock attributes."""
+        for name, _method in inspect.getmembers(source, inspect.iscoroutinefunction):
+            setattr(self, name, AsyncMock())
+
+
+# TODO: Remove me in Python 3.8
+class AsyncMock(CustomMockMixin, unittest.mock.MagicMock):
+    """
+    A MagicMock subclass to mock async callables.
+
+    Python 3.8 will introduce an AsyncMock class in the standard library that will have some more
+    features; this stand-in only overwrites the `__call__` method to an async version.
+    """
+    async def __call__(self, *args, **kwargs):
+        return super(AsyncMock, self).__call__(*args, **kwargs)
+
+
+# Create a guild instance to get a realistic Mock of `discord.Guild`
+guild_data = {
+    'id': 1,
+    'name': 'guild',
+    'region': 'Europe',
+    'verification_level': 2,
+    'default_notications': 1,
+    'afk_timeout': 100,
+    'icon': "icon.png",
+    'banner': 'banner.png',
+    'mfa_level': 1,
+    'splash': 'splash.png',
+    'system_channel_id': 464033278631084042,
+    'description': 'mocking is fun',
+    'max_presences': 10_000,
+    'max_members': 100_000,
+    'preferred_locale': 'UTC',
+    'owner_id': 1,
+    'afk_channel_id': 464033278631084042,
+}
+guild_instance = discord.Guild(data=guild_data, state=unittest.mock.MagicMock())
+
+
+class MockGuild(CustomMockMixin, unittest.mock.Mock, HashableMixin):
+    """
+    A `Mock` subclass to mock `discord.Guild` objects.
+
+    A MockGuild instance will follow the specifications of a `discord.Guild` instance. This means
+    that if the code you're testing tries to access an attribute or method that normally does not
+    exist for a `discord.Guild` object this will raise an `AttributeError`. This is to make sure our
+    tests fail if the code we're testing uses a `discord.Guild` object in the wrong way.
+
+    One restriction of that is that if the code tries to access an attribute that normally does not
+    exist for `discord.Guild` instance but was added dynamically, this will raise an exception with
+    the mocked object. To get around that, you can set the non-standard attribute explicitly for the
+    instance of `MockGuild`:
+
+    >>> guild = MockGuild()
+    >>> guild.attribute_that_normally_does_not_exist = unittest.mock.MagicMock()
+
+    In addition to attribute simulation, mocked guild object will pass an `isinstance` check against
+    `discord.Guild`:
+
+    >>> guild = MockGuild()
+    >>> isinstance(guild, discord.Guild)
+    True
+
+    For more info, see the `Mocking` section in `tests/README.md`.
+    """
+    def __init__(
+        self,
+        guild_id: int = 1,
+        roles: Optional[Iterable[MockRole]] = None,
+        members: Optional[Iterable[MockMember]] = None,
+        **kwargs,
+    ) -> None:
+        super().__init__(spec=guild_instance, **kwargs)
+
+        self.id = guild_id
+
+        self.roles = [MockRole("@everyone", 1)]
+        if roles:
+            self.roles.extend(roles)
+
+        self.members = []
+        if members:
+            self.members.extend(members)
+
+
+# Create a Role instance to get a realistic Mock of `discord.Role`
+role_data = {'name': 'role', 'id': 1}
+role_instance = discord.Role(guild=guild_instance, state=unittest.mock.MagicMock(), data=role_data)
+
+
+class MockRole(CustomMockMixin, unittest.mock.Mock, ColourMixin, HashableMixin):
+    """
+    A Mock subclass to mock `discord.Role` objects.
+
+    Instances of this class will follow the specifications of `discord.Role` instances. For more
+    information, see the `MockGuild` docstring.
+    """
+    def __init__(self, name: str = "role", role_id: int = 1, position: int = 1, **kwargs) -> None:
+        super().__init__(spec=role_instance, **kwargs)
+
+        self.name = name
+        self.id = role_id
+        self.position = position
+        self.mention = f'&{self.name}'
+
+    def __lt__(self, other):
+        """Simplified position-based comparisons similar to those of `discord.Role`."""
+        return self.position < other.position
+
+
+# Create a Member instance to get a realistic Mock of `discord.Member`
+member_data = {'user': 'lemon', 'roles': [1]}
+state_mock = unittest.mock.MagicMock()
+member_instance = discord.Member(data=member_data, guild=guild_instance, state=state_mock)
+
+
+class MockMember(CustomMockMixin, unittest.mock.Mock, ColourMixin, HashableMixin):
+    """
+    A Mock subclass to mock Member objects.
+
+    Instances of this class will follow the specifications of `discord.Member` instances. For more
+    information, see the `MockGuild` docstring.
+    """
+    def __init__(
+        self,
+        name: str = "member",
+        user_id: int = 1,
+        roles: Optional[Iterable[MockRole]] = None,
+        **kwargs,
+    ) -> None:
+        super().__init__(spec=member_instance, **kwargs)
+
+        self.name = name
+        self.id = user_id
+
+        self.roles = [MockRole("@everyone", 1)]
+        if roles:
+            self.roles.extend(roles)
+
+        self.mention = f"@{self.name}"
+
+
+# Create a Bot instance to get a realistic MagicMock of `discord.ext.commands.Bot`
+bot_instance = Bot(command_prefix=unittest.mock.MagicMock())
+
+
+class MockBot(CustomMockMixin, unittest.mock.MagicMock):
+    """
+    A MagicMock subclass to mock Bot objects.
+
+    Instances of this class will follow the specifications of `discord.ext.commands.Bot` instances.
+    For more information, see the `MockGuild` docstring.
+    """
+    def __init__(self, **kwargs) -> None:
+        super().__init__(spec=bot_instance, **kwargs)
+
+        # Our custom attributes and methods
+        self.http_session = unittest.mock.MagicMock()
+        self.api_client = unittest.mock.MagicMock()
+
+        # self.wait_for is *not* a coroutine function, but returns a coroutine nonetheless and
+        # and should therefore be awaited. (The documentation calls it a coroutine as well, which
+        # is technically incorrect, since it's a regular def.)
+        self.wait_for = AsyncMock()
+
+
+# Create a TextChannel instance to get a realistic MagicMock of `discord.TextChannel`
+channel_data = {
+    'id': 1,
+    'type': 'TextChannel',
+    'name': 'channel',
+    'parent_id': 1234567890,
+    'topic': 'topic',
+    'position': 1,
+    'nsfw': False,
+    'last_message_id': 1,
+}
+state = unittest.mock.MagicMock()
+guild = unittest.mock.MagicMock()
+channel_instance = discord.TextChannel(state=state, guild=guild, data=channel_data)
+
+
+class MockTextChannel(CustomMockMixin, unittest.mock.Mock, HashableMixin):
+    """
+    A MagicMock subclass to mock TextChannel objects.
+
+    Instances of this class will follow the specifications of `discord.TextChannel` instances. For
+    more information, see the `MockGuild` docstring.
+    """
+    def __init__(self, name: str = 'channel', channel_id: int = 1, **kwargs) -> None:
+        super().__init__(spec=channel_instance, **kwargs)
+        self.id = channel_id
+        self.name = name
+        self.guild = kwargs.get('guild', MockGuild())
+        self.mention = f"#{self.name}"
+
+
+# Create a Message instance to get a realistic MagicMock of `discord.Message`
+message_data = {
+    'id': 1,
+    'webhook_id': 431341013479718912,
+    'attachments': [],
+    'embeds': [],
+    'application': 'Python Discord',
+    'activity': 'mocking',
+    'channel': unittest.mock.MagicMock(),
+    'edited_timestamp': '2019-10-14T15:33:48+00:00',
+    'type': 'message',
+    'pinned': False,
+    'mention_everyone': False,
+    'tts': None,
+    'content': 'content',
+    'nonce': None,
+}
+state = unittest.mock.MagicMock()
+channel = unittest.mock.MagicMock()
+message_instance = discord.Message(state=state, channel=channel, data=message_data)
+
+
+# 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())
+
+
+class MockContext(CustomMockMixin, unittest.mock.MagicMock):
+    """
+    A MagicMock subclass to mock Context objects.
+
+    Instances of this class will follow the specifications of `discord.ext.commands.Context`
+    instances. For more information, see the `MockGuild` docstring.
+    """
+    def __init__(self, **kwargs) -> None:
+        super().__init__(spec=context_instance, **kwargs)
+        self.bot = kwargs.get('bot', MockBot())
+        self.guild = kwargs.get('guild', MockGuild())
+        self.author = kwargs.get('author', MockMember())
+        self.channel = kwargs.get('channel', MockTextChannel())
+        self.command = kwargs.get('command', unittest.mock.MagicMock())
+
+
+class MockMessage(CustomMockMixin, unittest.mock.MagicMock):
+    """
+    A MagicMock subclass to mock Message objects.
+
+    Instances of this class will follow the specifications of `discord.Message` instances. For more
+    information, see the `MockGuild` docstring.
+    """
+    def __init__(self, **kwargs) -> None:
+        super().__init__(spec=message_instance, **kwargs)
+        self.author = kwargs.get('author', MockMember())
+        self.channel = kwargs.get('channel', MockTextChannel())
+
+
+emoji_data = {'require_colons': True, 'managed': True, 'id': 1, 'name': 'hyperlemon'}
+emoji_instance = discord.Emoji(guild=MockGuild(), state=unittest.mock.MagicMock(), data=emoji_data)
+
+
+class MockEmoji(CustomMockMixin, unittest.mock.MagicMock):
+    """
+    A MagicMock subclass to mock Emoji objects.
+
+    Instances of this class will follow the specifications of `discord.Emoji` instances. For more
+    information, see the `MockGuild` docstring.
+    """
+    def __init__(self, **kwargs) -> None:
+        super().__init__(spec=emoji_instance, **kwargs)
+        self.guild = kwargs.get('guild', MockGuild())
+
+        # Get all coroutine functions and set them as AsyncMock attributes
+        self._extract_coroutine_methods_from_spec_instance(emoji_instance)
+
+
+partial_emoji_instance = discord.PartialEmoji(animated=False, name='guido')
+
+
+class MockPartialEmoji(CustomMockMixin, unittest.mock.MagicMock):
+    """
+    A MagicMock subclass to mock PartialEmoji objects.
+
+    Instances of this class will follow the specifications of `discord.PartialEmoji` instances. For
+    more information, see the `MockGuild` docstring.
+    """
+    def __init__(self, **kwargs) -> None:
+        super().__init__(spec=partial_emoji_instance, **kwargs)
+
+
+reaction_instance = discord.Reaction(message=MockMessage(), data={'me': True}, emoji=MockEmoji())
+
+
+class MockReaction(CustomMockMixin, unittest.mock.MagicMock):
+    """
+    A MagicMock subclass to mock Reaction objects.
+
+    Instances of this class will follow the specifications of `discord.Reaction` instances. For
+    more information, see the `MockGuild` docstring.
+    """
+    def __init__(self, **kwargs) -> None:
+        super().__init__(spec=reaction_instance, **kwargs)
+        self.emoji = kwargs.get('emoji', MockEmoji())
+        self.message = kwargs.get('message', MockMessage())