Fix typing issues and improve typing completeness across the library

Co-authored-by: Danny <Rapptz@users.noreply.github.com>
Co-authored-by: Josh <josh.ja.butt@gmail.com>

discord/ext/commands/help.py

@@ -22,13 +22,27 @@ FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 DEALINGS IN THE SOFTWARE.
 """
 
+from __future__ import annotations
+
 import itertools
 import copy
 import functools
-import inspect
 import re
 
-from typing import Optional, TYPE_CHECKING
+from typing import (
+    TYPE_CHECKING,
+    Optional,
+    Generator,
+    List,
+    TypeVar,
+    Callable,
+    Any,
+    Dict,
+    Tuple,
+    Iterable,
+    Sequence,
+    Mapping,
+)
 
 import discord.utils
 
@@ -36,7 +50,21 @@ from .core import Group, Command, get_signature_parameters
 from .errors import CommandError
 
 if TYPE_CHECKING:
+    from typing_extensions import Self
+    import inspect
+
+    import discord.abc
+
+    from .bot import BotBase
     from .context import Context
+    from .cog import Cog
+
+    from ._types import (
+        Check,
+        ContextT,
+        BotT,
+        _Bot,
+    )
 
 __all__ = (
     'Paginator',
@@ -45,7 +73,9 @@ __all__ = (
     'MinimalHelpCommand',
 )
 
-MISSING = discord.utils.MISSING
+FuncT = TypeVar('FuncT', bound=Callable[..., Any])
+
+MISSING: Any = discord.utils.MISSING
 
 # help -> shows info of bot on top/bottom and lists subcommands
 # help command -> shows detailed info of command
@@ -80,10 +110,10 @@ class Paginator:
 
     Attributes
     -----------
-    prefix: :class:`str`
-        The prefix inserted to every page. e.g. three backticks.
-    suffix: :class:`str`
-        The suffix appended at the end of every page. e.g. three backticks.
+    prefix: Optional[:class:`str`]
+        The prefix inserted to every page. e.g. three backticks, if any.
+    suffix: Optional[:class:`str`]
+        The suffix appended at the end of every page. e.g. three backticks, if any.
     max_size: :class:`int`
         The maximum amount of codepoints allowed in a page.
     linesep: :class:`str`
@@ -91,36 +121,38 @@ class Paginator:
             .. versionadded:: 1.7
     """
 
-    def __init__(self, prefix='```', suffix='```', max_size=2000, linesep='\n'):
-        self.prefix = prefix
-        self.suffix = suffix
-        self.max_size = max_size
-        self.linesep = linesep
+    def __init__(
+        self, prefix: Optional[str] = '```', suffix: Optional[str] = '```', max_size: int = 2000, linesep: str = '\n'
+    ) -> None:
+        self.prefix: Optional[str] = prefix
+        self.suffix: Optional[str] = suffix
+        self.max_size: int = max_size
+        self.linesep: str = linesep
         self.clear()
 
-    def clear(self):
+    def clear(self) -> None:
         """Clears the paginator to have no pages."""
         if self.prefix is not None:
-            self._current_page = [self.prefix]
-            self._count = len(self.prefix) + self._linesep_len  # prefix + newline
+            self._current_page: List[str] = [self.prefix]
+            self._count: int = len(self.prefix) + self._linesep_len  # prefix + newline
         else:
             self._current_page = []
             self._count = 0
-        self._pages = []
+        self._pages: List[str] = []
 
     @property
-    def _prefix_len(self):
+    def _prefix_len(self) -> int:
         return len(self.prefix) if self.prefix else 0
 
     @property
-    def _suffix_len(self):
+    def _suffix_len(self) -> int:
         return len(self.suffix) if self.suffix else 0
 
     @property
-    def _linesep_len(self):
+    def _linesep_len(self) -> int:
         return len(self.linesep)
 
-    def add_line(self, line='', *, empty=False):
+    def add_line(self, line: str = '', *, empty: bool = False) -> None:
         """Adds a line to the current page.
 
         If the line exceeds the :attr:`max_size` then an exception
@@ -152,7 +184,7 @@ class Paginator:
             self._current_page.append('')
             self._count += self._linesep_len
 
-    def close_page(self):
+    def close_page(self) -> None:
         """Prematurely terminate a page."""
         if self.suffix is not None:
             self._current_page.append(self.suffix)
@@ -165,36 +197,38 @@ class Paginator:
             self._current_page = []
             self._count = 0
 
-    def __len__(self):
+    def __len__(self) -> int:
         total = sum(len(p) for p in self._pages)
         return total + self._count
 
     @property
-    def pages(self):
+    def pages(self) -> List[str]:
         """List[:class:`str`]: Returns the rendered list of pages."""
         # we have more than just the prefix in our current page
         if len(self._current_page) > (0 if self.prefix is None else 1):
             self.close_page()
         return self._pages
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         fmt = '<Paginator prefix: {0.prefix!r} suffix: {0.suffix!r} linesep: {0.linesep!r} max_size: {0.max_size} count: {0._count}>'
         return fmt.format(self)
 
 
-def _not_overridden(f):
+def _not_overridden(f: FuncT) -> FuncT:
     f.__help_command_not_overridden__ = True
     return f
 
 
 class _HelpCommandImpl(Command):
-    def __init__(self, inject, *args, **kwargs):
+    def __init__(self, inject: HelpCommand, *args: Any, **kwargs: Any) -> None:
         super().__init__(inject.command_callback, *args, **kwargs)
-        self._original = inject
-        self._injected = inject
-        self.params = get_signature_parameters(inject.command_callback, globals(), skip_parameters=1)
+        self._original: HelpCommand = inject
+        self._injected: HelpCommand = inject
+        self.params: Dict[str, inspect.Parameter] = get_signature_parameters(
+            inject.command_callback, globals(), skip_parameters=1
+        )
 
-    async def prepare(self, ctx):
+    async def prepare(self, ctx: Context[Any]) -> None:
         self._injected = injected = self._original.copy()
         injected.context = ctx
         self.callback = injected.command_callback
@@ -209,7 +243,7 @@ class _HelpCommandImpl(Command):
 
         await super().prepare(ctx)
 
-    async def _parse_arguments(self, ctx):
+    async def _parse_arguments(self, ctx: Context[BotT]) -> None:
         # Make the parser think we don't have a cog so it doesn't
         # inject the parameter into `ctx.args`.
         original_cog = self.cog
@@ -219,22 +253,26 @@ class _HelpCommandImpl(Command):
         finally:
             self.cog = original_cog
 
-    async def _on_error_cog_implementation(self, dummy, ctx, error):
+    async def _on_error_cog_implementation(self, _, ctx: Context[BotT], error: CommandError) -> None:
         await self._injected.on_help_command_error(ctx, error)
 
-    def _inject_into_cog(self, cog):
+    def _inject_into_cog(self, cog: Cog) -> None:
         # Warning: hacky
 
         # Make the cog think that get_commands returns this command
         # as well if we inject it without modifying __cog_commands__
         # since that's used for the injection and ejection of cogs.
-        def wrapped_get_commands(*, _original=cog.get_commands):
+        def wrapped_get_commands(
+            *, _original: Callable[[], List[Command[Any, ..., Any]]] = cog.get_commands
+        ) -> List[Command[Any, ..., Any]]:
             ret = _original()
             ret.append(self)
             return ret
 
         # Ditto here
-        def wrapped_walk_commands(*, _original=cog.walk_commands):
+        def wrapped_walk_commands(
+            *, _original: Callable[[], Generator[Command[Any, ..., Any], None, None]] = cog.walk_commands
+        ):
             yield from _original()
             yield self
 
@@ -244,7 +282,7 @@ class _HelpCommandImpl(Command):
         cog.walk_commands = wrapped_walk_commands
         self.cog = cog
 
-    def _eject_cog(self):
+    def _eject_cog(self) -> None:
         if self.cog is None:
             return
 
@@ -298,7 +336,11 @@ class HelpCommand:
 
     MENTION_PATTERN = re.compile('|'.join(MENTION_TRANSFORMS.keys()))
 
-    def __new__(cls, *args, **kwargs):
+    if TYPE_CHECKING:
+        __original_kwargs__: Dict[str, Any]
+        __original_args__: Tuple[Any, ...]
+
+    def __new__(cls, *args: Any, **kwargs: Any) -> Self:
         # To prevent race conditions of a single instance while also allowing
         # for settings to be passed the original arguments passed must be assigned
         # to allow for easier copies (which will be made when the help command is actually called)
@@ -314,30 +356,31 @@ class HelpCommand:
         self.__original_args__ = deepcopy(args)
         return self
 
-    def __init__(self, **options):
-        self.show_hidden = options.pop('show_hidden', False)
-        self.verify_checks = options.pop('verify_checks', True)
+    def __init__(self, **options: Any) -> None:
+        self.show_hidden: bool = options.pop('show_hidden', False)
+        self.verify_checks: bool = options.pop('verify_checks', True)
+        self.command_attrs: Dict[str, Any]
         self.command_attrs = attrs = options.pop('command_attrs', {})
         attrs.setdefault('name', 'help')
         attrs.setdefault('help', 'Shows this message')
-        self.context: Context = MISSING
+        self.context: Context[_Bot] = MISSING
         self._command_impl = _HelpCommandImpl(self, **self.command_attrs)
 
-    def copy(self):
+    def copy(self) -> Self:
         obj = self.__class__(*self.__original_args__, **self.__original_kwargs__)
         obj._command_impl = self._command_impl
         return obj
 
-    def _add_to_bot(self, bot):
+    def _add_to_bot(self, bot: BotBase) -> None:
         command = _HelpCommandImpl(self, **self.command_attrs)
         bot.add_command(command)
         self._command_impl = command
 
-    def _remove_from_bot(self, bot):
+    def _remove_from_bot(self, bot: BotBase) -> None:
         bot.remove_command(self._command_impl.name)
         self._command_impl._eject_cog()
 
-    def add_check(self, func, /):
+    def add_check(self, func: Check[ContextT], /) -> None:
         """
         Adds a check to the help command.
 
@@ -355,7 +398,7 @@ class HelpCommand:
 
         self._command_impl.add_check(func)
 
-    def remove_check(self, func, /):
+    def remove_check(self, func: Check[ContextT], /) -> None:
         """
         Removes a check from the help command.
 
@@ -376,15 +419,15 @@ class HelpCommand:
 
         self._command_impl.remove_check(func)
 
-    def get_bot_mapping(self):
+    def get_bot_mapping(self) -> Dict[Optional[Cog], List[Command[Any, ..., Any]]]:
         """Retrieves the bot mapping passed to :meth:`send_bot_help`."""
         bot = self.context.bot
-        mapping = {cog: cog.get_commands() for cog in bot.cogs.values()}
+        mapping: Dict[Optional[Cog], List[Command[Any, ..., Any]]] = {cog: cog.get_commands() for cog in bot.cogs.values()}
         mapping[None] = [c for c in bot.commands if c.cog is None]
         return mapping
 
     @property
-    def invoked_with(self):
+    def invoked_with(self) -> Optional[str]:
         """Similar to :attr:`Context.invoked_with` except properly handles
         the case where :meth:`Context.send_help` is used.
 
@@ -395,7 +438,7 @@ class HelpCommand:
 
         Returns
         ---------
-        :class:`str`
+        Optional[:class:`str`]
             The command name that triggered this invocation.
         """
         command_name = self._command_impl.name
@@ -404,7 +447,7 @@ class HelpCommand:
             return command_name
         return ctx.invoked_with
 
-    def get_command_signature(self, command):
+    def get_command_signature(self, command: Command[Any, ..., Any]) -> str:
         """Retrieves the signature portion of the help page.
 
         Parameters
@@ -418,14 +461,14 @@ class HelpCommand:
             The signature for the command.
         """
 
-        parent = command.parent
+        parent: Optional[Group[Any, ..., Any]] = command.parent  # type: ignore - the parent will be a Group
         entries = []
         while parent is not None:
             if not parent.signature or parent.invoke_without_command:
                 entries.append(parent.name)
             else:
                 entries.append(parent.name + ' ' + parent.signature)
-            parent = parent.parent
+            parent = parent.parent  # type: ignore
         parent_sig = ' '.join(reversed(entries))
 
         if len(command.aliases) > 0:
@@ -439,7 +482,7 @@ class HelpCommand:
 
         return f'{self.context.clean_prefix}{alias} {command.signature}'
 
-    def remove_mentions(self, string):
+    def remove_mentions(self, string: str) -> str:
         """Removes mentions from the string to prevent abuse.
 
         This includes ``@everyone``, ``@here``, member mentions and role mentions.
@@ -450,13 +493,13 @@ class HelpCommand:
             The string with mentions removed.
         """
 
-        def replace(obj, *, transforms=self.MENTION_TRANSFORMS):
+        def replace(obj: re.Match, *, transforms: Dict[str, str] = self.MENTION_TRANSFORMS) -> str:
             return transforms.get(obj.group(0), '@invalid')
 
         return self.MENTION_PATTERN.sub(replace, string)
 
     @property
-    def cog(self):
+    def cog(self) -> Optional[Cog]:
         """A property for retrieving or setting the cog for the help command.
 
         When a cog is set for the help command, it is as-if the help command
@@ -473,7 +516,7 @@ class HelpCommand:
         return self._command_impl.cog
 
     @cog.setter
-    def cog(self, cog):
+    def cog(self, cog: Optional[Cog]) -> None:
         # Remove whatever cog is currently valid, if any
         self._command_impl._eject_cog()
 
@@ -481,7 +524,7 @@ class HelpCommand:
         if cog is not None:
             self._command_impl._inject_into_cog(cog)
 
-    def command_not_found(self, string):
+    def command_not_found(self, string: str) -> str:
         """|maybecoro|
 
         A method called when a command is not found in the help command.
@@ -502,7 +545,7 @@ class HelpCommand:
         """
         return f'No command called "{string}" found.'
 
-    def subcommand_not_found(self, command, string):
+    def subcommand_not_found(self, command: Command[Any, ..., Any], string: str) -> str:
         """|maybecoro|
 
         A method called when a command did not have a subcommand requested in the help command.
@@ -532,7 +575,13 @@ class HelpCommand:
             return f'Command "{command.qualified_name}" has no subcommand named {string}'
         return f'Command "{command.qualified_name}" has no subcommands.'
 
-    async def filter_commands(self, commands, *, sort=False, key=None):
+    async def filter_commands(
+        self,
+        commands: Iterable[Command[Any, ..., Any]],
+        *,
+        sort: bool = False,
+        key: Optional[Callable[[Command[Any, ..., Any]], Any]] = None,
+    ) -> List[Command[Any, ..., Any]]:
         """|coro|
 
         Returns a filtered list of commands and optionally sorts them.
@@ -546,7 +595,7 @@ class HelpCommand:
             An iterable of commands that are getting filtered.
         sort: :class:`bool`
             Whether to sort the result.
-        key: Optional[Callable[:class:`Command`, Any]]
+        key: Optional[Callable[[:class:`Command`], Any]]
             An optional key function to pass to :func:`py:sorted` that
             takes a :class:`Command` as its sole parameter. If ``sort`` is
             passed as ``True`` then this will default as the command name.
@@ -565,14 +614,14 @@ class HelpCommand:
         if self.verify_checks is False:
             # if we do not need to verify the checks then we can just
             # run it straight through normally without using await.
-            return sorted(iterator, key=key) if sort else list(iterator)
+            return sorted(iterator, key=key) if sort else list(iterator)  # type: ignore - the key shouldn't be None
 
         if self.verify_checks is None and not self.context.guild:
             # if verify_checks is None and we're in a DM, don't verify
-            return sorted(iterator, key=key) if sort else list(iterator)
+            return sorted(iterator, key=key) if sort else list(iterator)  # type: ignore
 
         # if we're here then we need to check every command if it can run
-        async def predicate(cmd):
+        async def predicate(cmd: Command[Any, ..., Any]) -> bool:
             try:
                 return await cmd.can_run(self.context)
             except CommandError:
@@ -588,7 +637,7 @@ class HelpCommand:
             ret.sort(key=key)
         return ret
 
-    def get_max_size(self, commands):
+    def get_max_size(self, commands: Sequence[Command[Any, ..., Any]]) -> int:
         """Returns the largest name length of the specified command list.
 
         Parameters
@@ -605,7 +654,7 @@ class HelpCommand:
         as_lengths = (discord.utils._string_width(c.name) for c in commands)
         return max(as_lengths, default=0)
 
-    def get_destination(self):
+    def get_destination(self) -> discord.abc.MessageableChannel:
         """Returns the :class:`~discord.abc.Messageable` where the help command will be output.
 
         You can override this method to customise the behaviour.
@@ -619,7 +668,7 @@ class HelpCommand:
         """
         return self.context.channel
 
-    async def send_error_message(self, error):
+    async def send_error_message(self, error: str) -> None:
         """|coro|
 
         Handles the implementation when an error happens in the help command.
@@ -644,7 +693,7 @@ class HelpCommand:
         await destination.send(error)
 
     @_not_overridden
-    async def on_help_command_error(self, ctx, error):
+    async def on_help_command_error(self, ctx: Context[BotT], error: CommandError) -> None:
         """|coro|
 
         The help command's error handler, as specified by :ref:`ext_commands_error_handler`.
@@ -664,7 +713,7 @@ class HelpCommand:
         """
         pass
 
-    async def send_bot_help(self, mapping):
+    async def send_bot_help(self, mapping: Mapping[Optional[Cog], List[Command[Any, ..., Any]]]) -> None:
         """|coro|
 
         Handles the implementation of the bot command page in the help command.
@@ -693,7 +742,7 @@ class HelpCommand:
         """
         return None
 
-    async def send_cog_help(self, cog):
+    async def send_cog_help(self, cog: Cog) -> None:
         """|coro|
 
         Handles the implementation of the cog page in the help command.
@@ -721,7 +770,7 @@ class HelpCommand:
         """
         return None
 
-    async def send_group_help(self, group):
+    async def send_group_help(self, group: Group[Any, ..., Any]) -> None:
         """|coro|
 
         Handles the implementation of the group page in the help command.
@@ -749,7 +798,7 @@ class HelpCommand:
         """
         return None
 
-    async def send_command_help(self, command):
+    async def send_command_help(self, command: Command[Any, ..., Any]) -> None:
         """|coro|
 
         Handles the implementation of the single command page in the help command.
@@ -787,7 +836,7 @@ class HelpCommand:
         """
         return None
 
-    async def prepare_help_command(self, ctx, command=None):
+    async def prepare_help_command(self, ctx: Context[BotT], command: Optional[str] = None) -> None:
         """|coro|
 
         A low level method that can be used to prepare the help command
@@ -811,7 +860,7 @@ class HelpCommand:
         """
         pass
 
-    async def command_callback(self, ctx, *, command=None):
+    async def command_callback(self, ctx: Context[BotT], *, command: Optional[str] = None) -> None:
         """|coro|
 
         The actual implementation of the help command.
@@ -856,7 +905,7 @@ class HelpCommand:
 
         for key in keys[1:]:
             try:
-                found = cmd.all_commands.get(key)
+                found = cmd.all_commands.get(key)  # type: ignore
             except AttributeError:
                 string = await maybe_coro(self.subcommand_not_found, cmd, self.remove_mentions(key))
                 return await self.send_error_message(string)
@@ -908,28 +957,28 @@ class DefaultHelpCommand(HelpCommand):
         The paginator used to paginate the help command output.
     """
 
-    def __init__(self, **options):
-        self.width = options.pop('width', 80)
-        self.indent = options.pop('indent', 2)
-        self.sort_commands = options.pop('sort_commands', True)
-        self.dm_help = options.pop('dm_help', False)
-        self.dm_help_threshold = options.pop('dm_help_threshold', 1000)
-        self.commands_heading = options.pop('commands_heading', "Commands:")
-        self.no_category = options.pop('no_category', 'No Category')
-        self.paginator = options.pop('paginator', None)
+    def __init__(self, **options: Any) -> None:
+        self.width: int = options.pop('width', 80)
+        self.indent: int = options.pop('indent', 2)
+        self.sort_commands: bool = options.pop('sort_commands', True)
+        self.dm_help: bool = options.pop('dm_help', False)
+        self.dm_help_threshold: int = options.pop('dm_help_threshold', 1000)
+        self.commands_heading: str = options.pop('commands_heading', "Commands:")
+        self.no_category: str = options.pop('no_category', 'No Category')
+        self.paginator: Paginator = options.pop('paginator', None)
 
         if self.paginator is None:
-            self.paginator = Paginator()
+            self.paginator: Paginator = Paginator()
 
         super().__init__(**options)
 
-    def shorten_text(self, text):
+    def shorten_text(self, text: str) -> str:
         """:class:`str`: Shortens text to fit into the :attr:`width`."""
         if len(text) > self.width:
             return text[: self.width - 3].rstrip() + '...'
         return text
 
-    def get_ending_note(self):
+    def get_ending_note(self) -> str:
         """:class:`str`: Returns help command's ending note. This is mainly useful to override for i18n purposes."""
         command_name = self.invoked_with
         return (
@@ -937,7 +986,9 @@ class DefaultHelpCommand(HelpCommand):
             f"You can also type {self.context.clean_prefix}{command_name} category for more info on a category."
         )
 
-    def add_indented_commands(self, commands, *, heading, max_size=None):
+    def add_indented_commands(
+        self, commands: Sequence[Command[Any, ..., Any]], *, heading: str, max_size: Optional[int] = None
+    ) -> None:
         """Indents a list of commands after the specified heading.
 
         The formatting is added to the :attr:`paginator`.
@@ -973,13 +1024,13 @@ class DefaultHelpCommand(HelpCommand):
             entry = f'{self.indent * " "}{name:<{width}} {command.short_doc}'
             self.paginator.add_line(self.shorten_text(entry))
 
-    async def send_pages(self):
+    async def send_pages(self) -> None:
         """A helper utility to send the page output from :attr:`paginator` to the destination."""
         destination = self.get_destination()
         for page in self.paginator.pages:
             await destination.send(page)
 
-    def add_command_formatting(self, command):
+    def add_command_formatting(self, command: Command[Any, ..., Any]) -> None:
         """A utility function to format the non-indented block of commands and groups.
 
         Parameters
@@ -1002,7 +1053,7 @@ class DefaultHelpCommand(HelpCommand):
                     self.paginator.add_line(line)
                 self.paginator.add_line()
 
-    def get_destination(self):
+    def get_destination(self) -> discord.abc.Messageable:
         ctx = self.context
         if self.dm_help is True:
             return ctx.author
@@ -1011,11 +1062,11 @@ class DefaultHelpCommand(HelpCommand):
         else:
             return ctx.channel
 
-    async def prepare_help_command(self, ctx, command):
+    async def prepare_help_command(self, ctx: Context[BotT], command: str) -> None:
         self.paginator.clear()
         await super().prepare_help_command(ctx, command)
 
-    async def send_bot_help(self, mapping):
+    async def send_bot_help(self, mapping: Mapping[Optional[Cog], List[Command[Any, ..., Any]]]) -> None:
         ctx = self.context
         bot = ctx.bot
 
@@ -1045,12 +1096,12 @@ class DefaultHelpCommand(HelpCommand):
 
         await self.send_pages()
 
-    async def send_command_help(self, command):
+    async def send_command_help(self, command: Command[Any, ..., Any]) -> None:
         self.add_command_formatting(command)
         self.paginator.close_page()
         await self.send_pages()
 
-    async def send_group_help(self, group):
+    async def send_group_help(self, group: Group[Any, ..., Any]) -> None:
         self.add_command_formatting(group)
 
         filtered = await self.filter_commands(group.commands, sort=self.sort_commands)
@@ -1064,7 +1115,7 @@ class DefaultHelpCommand(HelpCommand):
 
         await self.send_pages()
 
-    async def send_cog_help(self, cog):
+    async def send_cog_help(self, cog: Cog) -> None:
         if cog.description:
             self.paginator.add_line(cog.description, empty=True)
 
@@ -1111,27 +1162,27 @@ class MinimalHelpCommand(HelpCommand):
         The paginator used to paginate the help command output.
     """
 
-    def __init__(self, **options):
-        self.sort_commands = options.pop('sort_commands', True)
-        self.commands_heading = options.pop('commands_heading', "Commands")
-        self.dm_help = options.pop('dm_help', False)
-        self.dm_help_threshold = options.pop('dm_help_threshold', 1000)
-        self.aliases_heading = options.pop('aliases_heading', "Aliases:")
-        self.no_category = options.pop('no_category', 'No Category')
-        self.paginator = options.pop('paginator', None)
+    def __init__(self, **options: Any) -> None:
+        self.sort_commands: bool = options.pop('sort_commands', True)
+        self.commands_heading: str = options.pop('commands_heading', "Commands")
+        self.dm_help: bool = options.pop('dm_help', False)
+        self.dm_help_threshold: int = options.pop('dm_help_threshold', 1000)
+        self.aliases_heading: str = options.pop('aliases_heading', "Aliases:")
+        self.no_category: str = options.pop('no_category', 'No Category')
+        self.paginator: Paginator = options.pop('paginator', None)
 
         if self.paginator is None:
-            self.paginator = Paginator(suffix=None, prefix=None)
+            self.paginator: Paginator = Paginator(suffix=None, prefix=None)
 
         super().__init__(**options)
 
-    async def send_pages(self):
+    async def send_pages(self) -> None:
         """A helper utility to send the page output from :attr:`paginator` to the destination."""
         destination = self.get_destination()
         for page in self.paginator.pages:
             await destination.send(page)
 
-    def get_opening_note(self):
+    def get_opening_note(self) -> str:
         """Returns help command's opening note. This is mainly useful to override for i18n purposes.
 
         The default implementation returns ::
@@ -1150,10 +1201,10 @@ class MinimalHelpCommand(HelpCommand):
             f"You can also use `{self.context.clean_prefix}{command_name} [category]` for more info on a category."
         )
 
-    def get_command_signature(self, command):
+    def get_command_signature(self, command: Command[Any, ..., Any]) -> str:
         return f'{self.context.clean_prefix}{command.qualified_name} {command.signature}'
 
-    def get_ending_note(self):
+    def get_ending_note(self) -> str:
         """Return the help command's ending note. This is mainly useful to override for i18n purposes.
 
         The default implementation does nothing.
@@ -1163,9 +1214,9 @@ class MinimalHelpCommand(HelpCommand):
         :class:`str`
             The help command ending note.
         """
-        return None
+        return ''
 
-    def add_bot_commands_formatting(self, commands, heading):
+    def add_bot_commands_formatting(self, commands: Sequence[Command[Any, ..., Any]], heading: str) -> None:
         """Adds the minified bot heading with commands to the output.
 
         The formatting should be added to the :attr:`paginator`.
@@ -1186,7 +1237,7 @@ class MinimalHelpCommand(HelpCommand):
             self.paginator.add_line(f'__**{heading}**__')
             self.paginator.add_line(joined)
 
-    def add_subcommand_formatting(self, command):
+    def add_subcommand_formatting(self, command: Command[Any, ..., Any]) -> None:
         """Adds formatting information on a subcommand.
 
         The formatting should be added to the :attr:`paginator`.
@@ -1202,7 +1253,7 @@ class MinimalHelpCommand(HelpCommand):
         fmt = '{0}{1} \N{EN DASH} {2}' if command.short_doc else '{0}{1}'
         self.paginator.add_line(fmt.format(self.context.clean_prefix, command.qualified_name, command.short_doc))
 
-    def add_aliases_formatting(self, aliases):
+    def add_aliases_formatting(self, aliases: Sequence[str]) -> None:
         """Adds the formatting information on a command's aliases.
 
         The formatting should be added to the :attr:`paginator`.
@@ -1219,7 +1270,7 @@ class MinimalHelpCommand(HelpCommand):
         """
         self.paginator.add_line(f'**{self.aliases_heading}** {", ".join(aliases)}', empty=True)
 
-    def add_command_formatting(self, command):
+    def add_command_formatting(self, command: Command[Any, ..., Any]) -> None:
         """A utility function to format commands and groups.
 
         Parameters
@@ -1246,7 +1297,7 @@ class MinimalHelpCommand(HelpCommand):
                     self.paginator.add_line(line)
                 self.paginator.add_line()
 
-    def get_destination(self):
+    def get_destination(self) -> discord.abc.Messageable:
         ctx = self.context
         if self.dm_help is True:
             return ctx.author
@@ -1255,11 +1306,11 @@ class MinimalHelpCommand(HelpCommand):
         else:
             return ctx.channel
 
-    async def prepare_help_command(self, ctx, command):
+    async def prepare_help_command(self, ctx: Context[BotT], command: str) -> None:
         self.paginator.clear()
         await super().prepare_help_command(ctx, command)
 
-    async def send_bot_help(self, mapping):
+    async def send_bot_help(self, mapping: Mapping[Optional[Cog], List[Command[Any, ..., Any]]]) -> None:
         ctx = self.context
         bot = ctx.bot
 
@@ -1272,7 +1323,7 @@ class MinimalHelpCommand(HelpCommand):
 
         no_category = f'\u200b{self.no_category}'
 
-        def get_category(command, *, no_category=no_category):
+        def get_category(command: Command[Any, ..., Any], *, no_category: str = no_category) -> str:
             cog = command.cog
             return cog.qualified_name if cog is not None else no_category
 
@@ -1290,7 +1341,7 @@ class MinimalHelpCommand(HelpCommand):
 
         await self.send_pages()
 
-    async def send_cog_help(self, cog):
+    async def send_cog_help(self, cog: Cog) -> None:
         bot = self.context.bot
         if bot.description:
             self.paginator.add_line(bot.description, empty=True)
@@ -1315,7 +1366,7 @@ class MinimalHelpCommand(HelpCommand):
 
         await self.send_pages()
 
-    async def send_group_help(self, group):
+    async def send_group_help(self, group: Group[Any, ..., Any]) -> None:
         self.add_command_formatting(group)
 
         filtered = await self.filter_commands(group.commands, sort=self.sort_commands)
@@ -1335,7 +1386,7 @@ class MinimalHelpCommand(HelpCommand):
 
         await self.send_pages()
 
-    async def send_command_help(self, command):
+    async def send_command_help(self, command: Command[Any, ..., Any]) -> None:
         self.add_command_formatting(command)
         self.paginator.close_page()
         await self.send_pages()