[commands] Add support for NumPy style docstrings for commands

discord/ext/commands/core.py

@@ -44,6 +44,7 @@ from typing import (
     Union,
     overload,
 )
+import re
 
 import discord
 
@@ -54,6 +55,7 @@ from .converter import Greedy, run_converters
 from .cooldowns import BucketType, Cooldown, CooldownMapping, DynamicCooldownMapping, MaxConcurrency
 from .errors import *
 from .parameters import Parameter, Signature
+from discord.app_commands.commands import NUMPY_DOCSTRING_ARG_REGEX
 
 if TYPE_CHECKING:
     from typing_extensions import Concatenate, ParamSpec, Self
@@ -165,6 +167,43 @@ def get_signature_parameters(
     return params
 
 
+PARAMETER_HEADING_REGEX = re.compile(r'Parameters?\n---+\n', re.I)
+
+
+def _fold_text(input: str) -> str:
+    """Turns a single newline into a space, and multiple newlines into a newline."""
+
+    def replacer(m: re.Match[str]) -> str:
+        if len(m.group()) <= 1:
+            return ' '
+        return '\n'
+
+    return re.sub(r'\n+', replacer, inspect.cleandoc(input))
+
+
+def extract_descriptions_from_docstring(function: Callable[..., Any], params: Dict[str, Parameter], /) -> Optional[str]:
+    docstring = inspect.getdoc(function)
+
+    if docstring is None:
+        return None
+
+    divide = PARAMETER_HEADING_REGEX.split(docstring, 1)
+    if len(divide) == 1:
+        return docstring
+
+    description, param_docstring = divide
+    for match in NUMPY_DOCSTRING_ARG_REGEX.finditer(param_docstring):
+        name = match.group('name')
+        if name not in params:
+            continue
+
+        param = params[name]
+        if param.description is None:
+            param._description = _fold_text(match.group('description'))
+
+    return _fold_text(description.strip())
+
+
 def wrap_callback(coro: Callable[P, Coro[T]], /) -> Callable[P, Coro[Optional[T]]]:
     @functools.wraps(coro)
     async def wrapped(*args: P.args, **kwargs: P.kwargs) -> Optional[T]:
@@ -365,9 +404,7 @@ class Command(_BaseCommand, Generic[CogT, P, T]):
         if help_doc is not None:
             help_doc = inspect.cleandoc(help_doc)
         else:
-            help_doc = inspect.getdoc(func)
-            if isinstance(help_doc, bytes):
-                help_doc = help_doc.decode('utf-8')
+            help_doc = extract_descriptions_from_docstring(func, self.params)
 
         self.help: Optional[str] = help_doc
 

tests/test_ext_commands_description.py

@@ -0,0 +1,131 @@
+"""
+The MIT License (MIT)
+
+Copyright (c) 2015-present Rapptz
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+"""
+
+from __future__ import annotations
+
+from discord.ext import commands
+
+
+def test_ext_commands_descriptions_explicit():
+    @commands.command(help='This is the short description that will appear.')
+    async def describe(
+        ctx: commands.Context,
+        arg: str = commands.param(description='Description of arg.'),
+        arg2: int = commands.param(description='Description of arg2.'),
+    ) -> None:
+        ...
+
+    assert describe.help == 'This is the short description that will appear.'
+    assert describe.clean_params['arg'].description == 'Description of arg.'
+    assert describe.clean_params['arg2'].description == 'Description of arg2.'
+
+
+def test_ext_commands_descriptions_no_args():
+    @commands.command()
+    async def no_args(ctx: commands.Context) -> None:
+        """This is the short description that will appear."""
+
+    assert no_args.help == 'This is the short description that will appear.'
+
+
+def test_ext_commands_descriptions_numpy():
+    @commands.command()
+    async def numpy(ctx: commands.Context, arg: str, arg2: int) -> None:
+        """This is the short description that will appear.
+
+        This extended description will also appear in the command description.
+
+        Parameters
+        ----------
+        arg: str
+            Docstring description of arg.
+            This is the second line of the arg docstring.
+        arg2: int
+            Docstring description of arg2.
+        """
+
+    assert (
+        numpy.help
+        == 'This is the short description that will appear.\nThis extended description will also appear in the command description.'
+    )
+    assert (
+        numpy.clean_params['arg'].description
+        == 'Docstring description of arg. This is the second line of the arg docstring.'
+    )
+    assert numpy.clean_params['arg2'].description == 'Docstring description of arg2.'
+
+
+def test_ext_commands_descriptions_numpy_extras():
+    @commands.command()
+    async def numpy(ctx: commands.Context, arg: str, arg2: int) -> None:
+        """This is the short description that will appear.
+
+        This extended description will also appear in the command description.
+
+        Parameters
+        ----------
+        ctx: commands.Context
+            The interaction object.
+        arg: str
+            Docstring description of arg.
+            This is the second line of the arg docstring.
+        arg2: int
+            Docstring description of arg2.
+
+        Returns
+        -------
+        NoneType
+            This function does not return anything.
+        """
+
+    assert (
+        numpy.help
+        == 'This is the short description that will appear.\nThis extended description will also appear in the command description.'
+    )
+    assert (
+        numpy.clean_params['arg'].description
+        == 'Docstring description of arg. This is the second line of the arg docstring.'
+    )
+    assert numpy.clean_params['arg2'].description == 'Docstring description of arg2.'
+
+
+def test_ext_commands_descriptions_cog_commands():
+    class MyCog(commands.Cog):
+        @commands.command()
+        async def test(self, ctx: commands.Context, arg: str, arg2: int) -> None:
+            """Test command
+
+            Parameters
+            ----------
+            arg: str
+                Description of arg.
+                This is the second line of the arg description.
+            arg2: int
+                Description of arg2.
+            """
+
+    cog = MyCog()
+    assert cog.test.help == 'Test command'
+    assert cog.test.clean_params['arg'].description == 'Description of arg. This is the second line of the arg description.'
+    assert cog.test.clean_params['arg2'].description == 'Description of arg2.'