matthew/enhanced-discord.py
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[commands] Redesign extension exception flow.

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Instead of raising a whole variety of exceptions, they are now wrapped
into ExtensionError derived classes.

* ExtensionAlreadyLoaded
	* Raised when an extension is already loaded in Bot.load_extension
* ExtensionNotLoaded
	* Raised when an extension is not loaded, e.g. Bot.unload_extension
* NoEntryPointError
	* Raised when an extension does not have a `setup` function.
* ExtensionFailed
	* Raised when an extension's `setup` function fails.
* ExtensionNotFound
	* Raised when an extension's module import fails.
This commit is contained in:
Rapptz
2019-03-19 07:35:56 -04:00
parent 26e9b5bfac
commit d9e54d7dd3
3 changed files with 140 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

55
discord/ext/commands/bot.py
View File

@@ -38,7 +38,7 @@ import discord
from .core import GroupMixin, Command
from .view import StringView
from .context import Context
from .errors import CommandNotFound, CommandError
from . import errors
from .help import HelpCommand, DefaultHelpCommand
from .cog import Cog
@@ -571,14 +571,14 @@ class BotBase(GroupMixin):
setup = getattr(lib, 'setup')
except AttributeError:
del sys.modules[key]
raise discord.ClientException('extension {!r} ({!r}) does not have a setup function.'.format(key, lib))
raise errors.NoEntryPointError(key)
try:
setup(self)
except Exception:
except Exception as e:
self._remove_module_references(lib.__name__)
self._call_module_finalizers(lib, key)
raise
raise errors.ExtensionFailed(key, e) from e
else:
self._extensions[key] = lib
@@ -601,20 +601,25 @@ class BotBase(GroupMixin):
Raises
--------
ClientException
The extension does not have a setup function.
ImportError
ExtensionNotFound
The extension could not be imported.
Exception
Any other exception raised by the extension will be raised back
to the caller.
ExtensionAlreadyLoaded
The extension is already loaded.
NoEntryPointError
The extension does not have a setup function.
ExtensionFailed
The extension setup function had an execution error.
"""
if name in self._extensions:
return
raise errors.ExtensionAlreadyLoaded(name)
lib = importlib.import_module(name)
self._load_from_module_spec(lib, name)
try:
lib = importlib.import_module(name)
except ImportError as e:
raise errors.ExtensionNotFound(name, e) from e
else:
self._load_from_module_spec(lib, name)
def unload_extension(self, name):
"""Unloads an extension.
@@ -633,11 +638,16 @@ class BotBase(GroupMixin):
The extension name to unload. It must be dot separated like
regular Python imports if accessing a sub-module. e.g.
``foo.test`` if you want to import ``foo/test.py``.
Raises
-------
ExtensionNotLoaded
The extension was not loaded.
"""
lib = self._extensions.get(name)
if lib is None:
return
raise errors.ExtensionNotLoaded(name)
self._remove_module_references(lib.__name__)
self._call_module_finalizers(lib, name)
@@ -659,14 +669,19 @@ class BotBase(GroupMixin):
Raises
-------
Exception
Any exception raised by the extension will be raised back
to the caller.
ExtensionNotLoaded
The extension was not loaded.
ExtensionNotFound
The extension could not be imported.
NoEntryPointError
The extension does not have a setup function.
ExtensionFailed
The extension setup function had an execution error.
"""
lib = self._extensions.get(name)
if lib is None:
return
raise errors.ExtensionNotLoaded(name)
# get the previous module states from sys modules
modules = {
@@ -843,12 +858,12 @@ class BotBase(GroupMixin):
try:
if await self.can_run(ctx, call_once=True):
await ctx.command.invoke(ctx)
except CommandError as exc:
except errors.CommandError as exc:
await ctx.command.dispatch_error(ctx, exc)
else:
self.dispatch('command_completion', ctx)
elif ctx.invoked_with:
exc = CommandNotFound('Command "{}" is not found'.format(ctx.invoked_with))
exc = errors.CommandNotFound('Command "{}" is not found'.format(ctx.invoked_with))
self.dispatch('command_error', ctx, exc)
async def process_commands(self, message):

81
discord/ext/commands/errors.py
View File

@@ -34,7 +34,9 @@ __all__ = ['CommandError', 'MissingRequiredArgument', 'BadArgument',
'MissingPermissions', 'BotMissingPermissions', 'ConversionError',
'BadUnionArgument', 'ArgumentParsingError',
'UnexpectedQuoteError', 'InvalidEndOfQuotedStringError',
'ExpectedClosingQuoteError', ]
'ExpectedClosingQuoteError', 'ExtensionError', 'ExtensionAlreadyLoaded',
'ExtensionNotLoaded', 'NoEntryPointError', 'ExtensionFailed',
'ExtensionNotFound' ]
class CommandError(DiscordException):
r"""The base exception type for all command related errors.
@@ -283,3 +285,80 @@ class ExpectedClosingQuoteError(ArgumentParsingError):
def __init__(self, close_quote):
self.close_quote = close_quote
super().__init__('Expected closing {}.'.format(close_quote))
class ExtensionError(DiscordException):
"""Base exception for extension related errors.
This inherits from :exc:`~discord.DiscordException`.
Parameter
-----------
name: :class:`str`
The extension that had an error.
"""
def __init__(self, message=None, *args, name):
self.name = name
message = message or 'Extension {!r} had an error.'.format(name)
# clean-up @everyone and @here mentions
m = message.replace('@everyone', '@\u200beveryone').replace('@here', '@\u200bhere')
super().__init__(m, *args)
class ExtensionAlreadyLoaded(ExtensionError):
"""An exception raised when an extension has already been loaded.
This inherits from :exc:`ExtensionError`
"""
def __init__(self, name):
super().__init__('Extension {!r} is already loaded.'.format(name), name=name)
class ExtensionNotLoaded(ExtensionError):
"""An exception raised when an extension was not loaded.
This inherits from :exc:`ExtensionError`
"""
def __init__(self, name):
super().__init__('Extension {!r} has not been loaded.'.format(name), name=name)
class NoEntryPointError(ExtensionError):
"""An exception raised when an extension does not have a ``setup`` entry point function.
This inherits from :exc:`ExtensionError`
"""
def __init__(self, name):
super().__init__("Extension {!r} has no 'setup' function.".format(name), name=name)
class ExtensionFailed(ExtensionError):
"""An exception raised when an extension failed to load during execution of the ``setup`` entry point.
This inherits from :exc:`ExtensionError`
Attributes
-----------
name: :class:`str`
The extension that had the error.
original: :exc:`Exception`
The original exception that was raised. You can also get this via
the ``__cause__`` attribute.
"""
def __init__(self, name, original):
self.original = original
fmt = 'Extension {0!r} raised an error: {1.__class__.__name__}: {1}'
super().__init__(fmt.format(name, original), name=name)
class ExtensionNotFound(ExtensionError):
"""An exception raised when an extension failed to be imported.
This inherits from :exc:`ExtensionError`
Attributes
-----------
name: :class:`str`
The extension that had the error.
original: :exc:`ImportError`
The original exception that was raised. You can also get this via
the ``__cause__`` attribute.
"""
def __init__(self, name, original):
self.original = original
fmt = 'Extension {0!r} could not be loaded.'
super().__init__(fmt.format(name), name=name)