ansible-later/env_27/lib/python2.7/site-packages/flake8/plugins/manager.py
2019-04-11 13:00:36 +02:00

530 lines
17 KiB
Python

"""Plugin loading and management logic and classes."""
import logging
import sys
import entrypoints
from flake8 import exceptions
from flake8 import utils
if sys.version_info >= (3, 3):
import collections.abc as collections_abc
else:
import collections as collections_abc
LOG = logging.getLogger(__name__)
__all__ = ("Checkers", "Plugin", "PluginManager", "ReportFormatters")
NO_GROUP_FOUND = object()
class Plugin(object):
"""Wrap an EntryPoint from setuptools and other logic."""
def __init__(self, name, entry_point, local=False):
"""Initialize our Plugin.
:param str name:
Name of the entry-point as it was registered with setuptools.
:param entry_point:
EntryPoint returned by setuptools.
:type entry_point:
setuptools.EntryPoint
:param bool local:
Is this a repo-local plugin?
"""
self.name = name
self.entry_point = entry_point
self.local = local
self._plugin = None
self._parameters = None
self._parameter_names = None
self._group = None
self._plugin_name = None
self._version = None
def __repr__(self):
"""Provide an easy to read description of the current plugin."""
return 'Plugin(name="{0}", entry_point="{1}")'.format(
self.name, self.entry_point
)
def to_dictionary(self):
"""Convert this plugin to a dictionary."""
return {
"name": self.name,
"parameters": self.parameters,
"parameter_names": self.parameter_names,
"plugin": self.plugin,
"plugin_name": self.plugin_name,
}
def is_in_a_group(self):
"""Determine if this plugin is in a group.
:returns:
True if the plugin is in a group, otherwise False.
:rtype:
bool
"""
return self.group() is not None
def group(self):
"""Find and parse the group the plugin is in."""
if self._group is None:
name = self.name.split(".", 1)
if len(name) > 1:
self._group = name[0]
else:
self._group = NO_GROUP_FOUND
if self._group is NO_GROUP_FOUND:
return None
return self._group
@property
def parameters(self):
"""List of arguments that need to be passed to the plugin."""
if self._parameters is None:
self._parameters = utils.parameters_for(self)
return self._parameters
@property
def parameter_names(self):
"""List of argument names that need to be passed to the plugin."""
if self._parameter_names is None:
self._parameter_names = list(self.parameters)
return self._parameter_names
@property
def plugin(self):
"""Load and return the plugin associated with the entry-point.
This property implicitly loads the plugin and then caches it.
"""
self.load_plugin()
return self._plugin
@property
def version(self):
"""Return the version of the plugin."""
if self._version is None:
if self.is_in_a_group():
self._version = version_for(self)
else:
self._version = self.plugin.version
return self._version
@property
def plugin_name(self):
"""Return the name of the plugin."""
if self._plugin_name is None:
if self.is_in_a_group():
self._plugin_name = self.group()
else:
self._plugin_name = self.plugin.name
return self._plugin_name
@property
def off_by_default(self):
"""Return whether the plugin is ignored by default."""
return getattr(self.plugin, "off_by_default", False)
def execute(self, *args, **kwargs):
r"""Call the plugin with \*args and \*\*kwargs."""
return self.plugin(*args, **kwargs) # pylint: disable=not-callable
def _load(self):
self._plugin = self.entry_point.load()
if not callable(self._plugin):
msg = (
"Plugin %r is not a callable. It might be written for an"
" older version of flake8 and might not work with this"
" version" % self._plugin
)
LOG.critical(msg)
raise TypeError(msg)
def load_plugin(self):
"""Retrieve the plugin for this entry-point.
This loads the plugin, stores it on the instance and then returns it.
It does not reload it after the first time, it merely returns the
cached plugin.
:returns:
Nothing
"""
if self._plugin is None:
LOG.info('Loading plugin "%s" from entry-point.', self.name)
try:
self._load()
except Exception as load_exception:
LOG.exception(load_exception)
failed_to_load = exceptions.FailedToLoadPlugin(
plugin=self, exception=load_exception
)
LOG.critical(str(failed_to_load))
raise failed_to_load
def enable(self, optmanager, options=None):
"""Remove plugin name from the default ignore list."""
optmanager.remove_from_default_ignore([self.name])
optmanager.extend_default_select([self.name])
if not options:
return
try:
options.ignore.remove(self.name)
except (ValueError, KeyError):
LOG.debug(
"Attempted to remove %s from the ignore list but it was "
"not a member of the list.",
self.name,
)
def disable(self, optmanager):
"""Add the plugin name to the default ignore list."""
optmanager.extend_default_ignore([self.name])
def provide_options(self, optmanager, options, extra_args):
"""Pass the parsed options and extra arguments to the plugin."""
parse_options = getattr(self.plugin, "parse_options", None)
if parse_options is not None:
LOG.debug('Providing options to plugin "%s".', self.name)
try:
parse_options(optmanager, options, extra_args)
except TypeError:
parse_options(options)
if self.name in options.enable_extensions:
self.enable(optmanager, options)
def register_options(self, optmanager):
"""Register the plugin's command-line options on the OptionManager.
:param optmanager:
Instantiated OptionManager to register options on.
:type optmanager:
flake8.options.manager.OptionManager
:returns:
Nothing
"""
add_options = getattr(self.plugin, "add_options", None)
if add_options is not None:
LOG.debug(
'Registering options from plugin "%s" on OptionManager %r',
self.name,
optmanager,
)
add_options(optmanager)
if self.off_by_default:
self.disable(optmanager)
class PluginManager(object): # pylint: disable=too-few-public-methods
"""Find and manage plugins consistently."""
def __init__(self, namespace, local_plugins=None):
"""Initialize the manager.
:param str namespace:
Namespace of the plugins to manage, e.g., 'flake8.extension'.
:param list local_plugins:
Plugins from config (as "X = path.to:Plugin" strings).
"""
self.namespace = namespace
self.plugins = {}
self.names = []
self._load_local_plugins(local_plugins or [])
self._load_entrypoint_plugins()
def _load_local_plugins(self, local_plugins):
"""Load local plugins from config.
:param list local_plugins:
Plugins from config (as "X = path.to:Plugin" strings).
"""
for plugin_str in local_plugins:
name, _, entry_str = plugin_str.partition("=")
name, entry_str = name.strip(), entry_str.strip()
entry_point = entrypoints.EntryPoint.from_string(entry_str, name)
self._load_plugin_from_entrypoint(entry_point, local=True)
def _load_entrypoint_plugins(self):
LOG.info('Loading entry-points for "%s".', self.namespace)
for entry_point in entrypoints.get_group_all(self.namespace):
if entry_point.name == "per-file-ignores":
LOG.warning(
"flake8-per-file-ignores plugin is incompatible with "
"flake8>=3.7 (which implements per-file-ignores itself)."
)
continue
self._load_plugin_from_entrypoint(entry_point)
def _load_plugin_from_entrypoint(self, entry_point, local=False):
"""Load a plugin from a setuptools EntryPoint.
:param EntryPoint entry_point:
EntryPoint to load plugin from.
:param bool local:
Is this a repo-local plugin?
"""
name = entry_point.name
self.plugins[name] = Plugin(name, entry_point, local=local)
self.names.append(name)
LOG.debug('Loaded %r for plugin "%s".', self.plugins[name], name)
def map(self, func, *args, **kwargs):
r"""Call ``func`` with the plugin and \*args and \**kwargs after.
This yields the return value from ``func`` for each plugin.
:param collections.Callable func:
Function to call with each plugin. Signature should at least be:
.. code-block:: python
def myfunc(plugin):
pass
Any extra positional or keyword arguments specified with map will
be passed along to this function after the plugin. The plugin
passed is a :class:`~flake8.plugins.manager.Plugin`.
:param args:
Positional arguments to pass to ``func`` after each plugin.
:param kwargs:
Keyword arguments to pass to ``func`` after each plugin.
"""
for name in self.names:
yield func(self.plugins[name], *args, **kwargs)
def versions(self):
# () -> (str, str)
"""Generate the versions of plugins.
:returns:
Tuples of the plugin_name and version
:rtype:
tuple
"""
plugins_seen = set()
for entry_point_name in self.names:
plugin = self.plugins[entry_point_name]
plugin_name = plugin.plugin_name
if plugin.plugin_name in plugins_seen:
continue
plugins_seen.add(plugin_name)
yield (plugin_name, plugin.version)
def version_for(plugin):
# (Plugin) -> Optional[str]
"""Determine the version of a plugin by its module.
:param plugin:
The loaded plugin
:type plugin:
Plugin
:returns:
version string for the module
:rtype:
str
"""
module_name = plugin.plugin.__module__
try:
module = __import__(module_name)
except ImportError:
return None
return getattr(module, "__version__", None)
class PluginTypeManager(object):
"""Parent class for most of the specific plugin types."""
namespace = None
def __init__(self, local_plugins=None):
"""Initialize the plugin type's manager.
:param list local_plugins:
Plugins from config file instead of entry-points
"""
self.manager = PluginManager(
self.namespace, local_plugins=local_plugins
)
self.plugins_loaded = False
def __contains__(self, name):
"""Check if the entry-point name is in this plugin type manager."""
LOG.debug('Checking for "%s" in plugin type manager.', name)
return name in self.plugins
def __getitem__(self, name):
"""Retrieve a plugin by its name."""
LOG.debug('Retrieving plugin for "%s".', name)
return self.plugins[name]
def get(self, name, default=None):
"""Retrieve the plugin referred to by ``name`` or return the default.
:param str name:
Name of the plugin to retrieve.
:param default:
Default value to return.
:returns:
Plugin object referred to by name, if it exists.
:rtype:
:class:`Plugin`
"""
if name in self:
return self[name]
return default
@property
def names(self):
"""Proxy attribute to underlying manager."""
return self.manager.names
@property
def plugins(self):
"""Proxy attribute to underlying manager."""
return self.manager.plugins
@staticmethod
def _generate_call_function(method_name, optmanager, *args, **kwargs):
def generated_function(plugin): # noqa: D105
method = getattr(plugin, method_name, None)
if method is not None and isinstance(
method, collections_abc.Callable
):
return method(optmanager, *args, **kwargs)
return generated_function
def load_plugins(self):
"""Load all plugins of this type that are managed by this manager."""
if self.plugins_loaded:
return
def load_plugin(plugin):
"""Call each plugin's load_plugin method."""
return plugin.load_plugin()
plugins = list(self.manager.map(load_plugin))
# Do not set plugins_loaded if we run into an exception
self.plugins_loaded = True
return plugins
def register_plugin_versions(self, optmanager):
"""Register the plugins and their versions with the OptionManager."""
self.load_plugins()
for (plugin_name, version) in self.manager.versions():
optmanager.register_plugin(name=plugin_name, version=version)
def register_options(self, optmanager):
"""Register all of the checkers' options to the OptionManager."""
self.load_plugins()
call_register_options = self._generate_call_function(
"register_options", optmanager
)
list(self.manager.map(call_register_options))
def provide_options(self, optmanager, options, extra_args):
"""Provide parsed options and extra arguments to the plugins."""
call_provide_options = self._generate_call_function(
"provide_options", optmanager, options, extra_args
)
list(self.manager.map(call_provide_options))
class Checkers(PluginTypeManager):
"""All of the checkers registered through entry-points or config."""
namespace = "flake8.extension"
def checks_expecting(self, argument_name):
"""Retrieve checks that expect an argument with the specified name.
Find all checker plugins that are expecting a specific argument.
"""
for plugin in self.plugins.values():
if argument_name == plugin.parameter_names[0]:
yield plugin
def to_dictionary(self):
"""Return a dictionary of AST and line-based plugins."""
return {
"ast_plugins": [
plugin.to_dictionary() for plugin in self.ast_plugins
],
"logical_line_plugins": [
plugin.to_dictionary() for plugin in self.logical_line_plugins
],
"physical_line_plugins": [
plugin.to_dictionary()
for plugin in self.physical_line_plugins
],
}
def register_options(self, optmanager):
"""Register all of the checkers' options to the OptionManager.
This also ensures that plugins that are not part of a group and are
enabled by default are enabled on the option manager.
"""
# NOTE(sigmavirus24) We reproduce a little of
# PluginTypeManager.register_options to reduce the number of times
# that we loop over the list of plugins. Instead of looping twice,
# option registration and enabling the plugin, we loop once with one
# function to map over the plugins.
self.load_plugins()
call_register_options = self._generate_call_function(
"register_options", optmanager
)
def register_and_enable(plugin):
call_register_options(plugin)
if plugin.group() is None and not plugin.off_by_default:
plugin.enable(optmanager)
list(self.manager.map(register_and_enable))
@property
def ast_plugins(self):
"""List of plugins that expect the AST tree."""
plugins = getattr(self, "_ast_plugins", [])
if not plugins:
plugins = list(self.checks_expecting("tree"))
self._ast_plugins = plugins
return plugins
@property
def logical_line_plugins(self):
"""List of plugins that expect the logical lines."""
plugins = getattr(self, "_logical_line_plugins", [])
if not plugins:
plugins = list(self.checks_expecting("logical_line"))
self._logical_line_plugins = plugins
return plugins
@property
def physical_line_plugins(self):
"""List of plugins that expect the physical lines."""
plugins = getattr(self, "_physical_line_plugins", [])
if not plugins:
plugins = list(self.checks_expecting("physical_line"))
self._physical_line_plugins = plugins
return plugins
class ReportFormatters(PluginTypeManager):
"""All of the report formatters registered through entry-points/config."""
namespace = "flake8.report"