Source code for coalib.bears.Bear

import inspect
import traceback
from functools import partial
from os import makedirs
from os.path import join, abspath, exists
import requests
from appdirs import user_data_dir

from pyprint.Printer import Printer

from coala_utils.decorators import (enforce_signature, classproperty,

from coalib.bears.BEAR_KIND import BEAR_KIND
from coalib.output.printers.LogPrinter import LogPrinterMixin
from coalib.results.Result import Result
from coalib.results.TextPosition import ZeroOffsetError
from coalib.settings.FunctionMetadata import FunctionMetadata
from coalib.settings.Section import Section
from coalib.settings.ConfigurationGathering import get_config_directory

from .meta import bearclass

[docs]class Bear(Printer, LogPrinterMixin, metaclass=bearclass): """ A bear contains the actual subroutine that is responsible for checking source code for certain specifications. However it can actually do whatever it wants with the files it gets. If you are missing some Result type, feel free to contact us and/or help us extending the coalib. This is the base class for every bear. If you want to write a bear, you will probably want to look at the GlobalBear and LocalBear classes that inherit from this class. In any case you'll want to overwrite at least the run method. You can send debug/warning/error messages through the debug(), warn(), err() functions. These will send the appropriate messages so that they are outputted. Be aware that if you use err(), you are expected to also terminate the bear run-through immediately. Settings are available at all times through self.section. To indicate which languages your bear supports, just give it the ``LANGUAGES`` value which should be a set of string(s): >>> from dependency_management.requirements.PackageRequirement import ( ... PackageRequirement) >>> from dependency_management.requirements.PipRequirement import ( ... PipRequirement) >>> class SomeBear(Bear): ... LANGUAGES = {'C', 'CPP','C#', 'D'} To indicate the requirements of the bear, assign ``REQUIREMENTS`` a set with instances of ``PackageRequirements``. >>> class SomeBear(Bear): ... REQUIREMENTS = { ... PackageRequirement('pip', 'coala_decorators', '0.2.1')} If your bear uses requirements from a manager we have a subclass from, you can use the subclass, such as ``PipRequirement``, without specifying manager: >>> class SomeBear(Bear): ... REQUIREMENTS = {PipRequirement('coala_decorators', '0.2.1')} To specify additional attributes to your bear, use the following: >>> class SomeBear(Bear): ... AUTHORS = {'Jon Snow'} ... AUTHORS_EMAILS = {''} ... MAINTAINERS = {'Catelyn Stark'} ... MAINTAINERS_EMAILS = {''} ... LICENSE = 'AGPL-3.0' ... ASCIINEMA_URL = '' If the maintainers are the same as the authors, they can be omitted: >>> class SomeBear(Bear): ... AUTHORS = {'Jon Snow'} ... AUTHORS_EMAILS = {''} >>> SomeBear.maintainers {'Jon Snow'} >>> SomeBear.maintainers_emails {''} If your bear needs to include local files, then specify it giving strings containing relative file paths to the INCLUDE_LOCAL_FILES set: >>> class SomeBear(Bear): ... INCLUDE_LOCAL_FILES = {'checkstyle.jar', 'google_checks.xml'} To keep track easier of what a bear can do, simply tell it to the CAN_FIX and the CAN_DETECT sets. Possible values: >>> CAN_DETECT = {'Syntax', 'Formatting', 'Security', 'Complexity', 'Smell', ... 'Unused Code', 'Redundancy', 'Variable Misuse', 'Spelling', ... 'Memory Leak', 'Documentation', 'Duplication', 'Commented Code', ... 'Grammar', 'Missing Import', 'Unreachable Code', 'Undefined Element', ... 'Code Simplification', 'Statistics'} >>> CAN_FIX = {'Syntax', ...} Specifying something to CAN_FIX makes it obvious that it can be detected too, so it may be omitted: >>> class SomeBear(Bear): ... CAN_DETECT = {'Syntax', 'Security'} ... CAN_FIX = {'Redundancy'} >>> list(sorted(SomeBear.can_detect)) ['Redundancy', 'Security', 'Syntax'] Every bear has a data directory which is unique to that particular bear: >>> class SomeBear(Bear): pass >>> class SomeOtherBear(Bear): pass >>> SomeBear.data_dir == SomeOtherBear.data_dir False BEAR_DEPS contains bear classes that are to be executed before this bear gets executed. The results of these bears will then be passed to the run method as a dict via the dependency_results argument. The dict will have the name of the Bear as key and the list of its results as results: >>> class SomeBear(Bear): pass >>> class SomeOtherBear(Bear): ... BEAR_DEPS = {SomeBear} >>> SomeOtherBear.BEAR_DEPS {<class 'coalib.bears.Bear.SomeBear'>} Every bear resides in some directory which is specified by the source_location attribute: >>> class SomeBear(Bear): pass >>> SomeBear.source_location '' Every linter bear makes use of an executable tool for its operations. The SEE_MORE attribute provides a link to the main page of the linter tool: >>> class PyLintBear(Bear): ... SEE_MORE = '' >>> PyLintBear.SEE_MORE '' In the future, bears will not survive without aspects. aspects are defined as part of the ``class`` statement's parameter list. According to the classic ``CAN_DETECT`` and ``CAN_FIX`` attributes, aspects can either be only ``'detect'``-able or also ``'fix'``-able: >>> from coalib.bearlib.aspects.Metadata import CommitMessage >>> class aspectsCommitBear(Bear, aspects={ ... 'detect': [CommitMessage.Shortlog.ColonExistence], ... 'fix': [CommitMessage.Shortlog.TrailingPeriod], ... }, languages=['Python']): ... pass >>> aspectsCommitBear.aspects['detect'] [<aspectclass 'Root.Metadata.CommitMessage.Shortlog.ColonExistence'>] >>> aspectsCommitBear.aspects['fix'] [<aspectclass 'Root.Metadata.CommitMessage.Shortlog.TrailingPeriod'>] To indicate the bear uses raw files, set ``USE_RAW_FILES`` to True: >>> class RawFileBear(Bear): ... USE_RAW_FILES = True >>> RawFileBear.USE_RAW_FILES True However if ``USE_RAW_FILES`` is enabled the Bear is in charge of managing the file (opening the file, closing the file, reading the file, etc). """ LANGUAGES = set() REQUIREMENTS = set() AUTHORS = set() AUTHORS_EMAILS = set() MAINTAINERS = set() MAINTAINERS_EMAILS = set() PLATFORMS = {'any'} LICENSE = '' INCLUDE_LOCAL_FILES = set() CAN_DETECT = set() CAN_FIX = set() ASCIINEMA_URL = '' SEE_MORE = '' BEAR_DEPS = set() USE_RAW_FILES = False @classproperty def name(cls): """ :return: The name of the bear """ return cls.__name__ @classproperty def can_detect(cls): """ :return: A set that contains everything a bear can detect, gathering information from what it can fix too. """ return cls.CAN_DETECT | cls.CAN_FIX @classproperty def source_location(cls): """ :return: The file path where the bear was fetched from. """ return inspect.getfile(cls) @classproperty def maintainers(cls): """ :return: A set containing ``MAINTAINERS`` if specified, else takes ``AUTHORS`` by default. """ return cls.AUTHORS if cls.MAINTAINERS == set() else cls.MAINTAINERS @classproperty def maintainers_emails(cls): """ :return: A set containing ``MAINTAINERS_EMAILS`` if specified, else takes ``AUTHORS_EMAILS`` by default. """ return (cls.AUTHORS_EMAILS if cls.MAINTAINERS_EMAILS == set() else cls.MAINTAINERS_EMAILS) @enforce_signature def __init__(self, section: Section, message_queue, timeout=0): """ Constructs a new bear. :param section: The section object where bear settings are contained. :param message_queue: The queue object for messages. Can be ``None``. :param timeout: The time the bear is allowed to run. To set no time limit, use 0. :raises TypeError: Raised when ``message_queue`` is no queue. :raises RuntimeError: Raised when bear requirements are not fulfilled. """ Printer.__init__(self) if message_queue is not None and not hasattr(message_queue, 'put'): raise TypeError('message_queue has to be a Queue or None.') self.section = section self.message_queue = message_queue self.timeout = timeout self.setup_dependencies() cp = type(self).check_prerequisites() if cp is not True: error_string = ('The bear ' + + ' does not fulfill all requirements.') if cp is not False: error_string += ' ' + cp self.err(error_string) raise RuntimeError(error_string) def _print(self, output, **kwargs): self.debug(output)
[docs] def log_message(self, log_message, timestamp=None, **kwargs): if self.message_queue is not None: self.message_queue.put(log_message)
[docs] def run(self, *args, dependency_results=None, **kwargs): raise NotImplementedError
[docs] def run_bear_from_section(self, args, kwargs): try: # Don't get `language` setting from `section.contents` if self.section.language and ( 'language' in self.get_metadata()._optional_params or 'language' in self.get_metadata()._non_optional_params): kwargs['language'] = self.section.language kwargs.update( self.get_metadata().create_params_from_section(self.section)) except ValueError as err: self.warn('The bear {} cannot be executed.'.format(, str(err)) return return*args, **kwargs)
[docs] def execute(self, *args, debug=False, **kwargs): name = try: self.debug('Running bear {}...'.format(name)) # If `dependency_results` kwargs is defined but there are no # dependency results (usually in Bear that has no dependency) # delete the `dependency_results` kwargs, since most Bears don't # define `dependency_results` kwargs in its `run()` function. if ('dependency_results' in kwargs and kwargs['dependency_results'] is None and not self.BEAR_DEPS): del kwargs['dependency_results'] # If it's already a list it won't change it result = self.run_bear_from_section(args, kwargs) return [] if result is None else list(result) except (Exception, SystemExit) as exc: if debug and not isinstance(exc, SystemExit): raise if isinstance(exc, ZeroOffsetError): self.err('Bear {} violated one-based offset convention.' .format(name), str(exc)) if self.kind() == BEAR_KIND.LOCAL: self.err('Bear {} failed to run on file {}. Take a look ' 'at debug messages (`-V`) for further ' 'information.'.format(name, args[0])) else: self.err('Bear {} failed to run. Take a look ' 'at debug messages (`-V`) for further ' 'information.'.format(name)) self.debug( 'The bear {bear} raised an exception. If you are the author ' 'of this bear, please make sure to catch all exceptions. If ' 'not and this error annoys you, you might want to get in ' 'contact with the author of this bear.\n\nTraceback ' 'information is provided below:\n\n{traceback}' '\n'.format(bear=name, traceback=traceback.format_exc()))
[docs] @staticmethod def kind(): """ :return: The kind of the bear """ raise NotImplementedError
[docs] @classmethod def get_metadata(cls): """ :return: Metadata for the run function. However parameters like ``self`` or parameters implicitly used by coala (e.g. filename for local bears) are already removed. """ return FunctionMetadata.from_function(, omit={'self', 'dependency_results', 'language'})
@classmethod def __json__(cls): """ Override JSON export of ``Bear`` object. """ # json cannot serialize properties, so drop them _dict = {key: value for key, value in get_public_members(cls).items() if not isinstance(value, property)} metadata = cls.get_metadata() non_optional_params = metadata.non_optional_params optional_params = metadata.optional_params _dict['metadata'] = { 'desc': metadata.desc, 'non_optional_params': ({param: non_optional_params[param][0]} for param in non_optional_params), 'optional_params': ({param: optional_params[param][0]} for param in optional_params)} if hasattr(cls, 'languages'): _dict['languages'] = (str(language) for language in cls.languages) return _dict
[docs] @classmethod def missing_dependencies(cls, lst): """ Checks if the given list contains all dependencies. :param lst: A list of all already resolved bear classes (not instances). :return: A set of missing dependencies. """ return set(cls.BEAR_DEPS) - set(lst)
[docs] @classmethod def get_non_optional_settings(cls, recurse=True): """ This method has to determine which settings are needed by this bear. The user will be prompted for needed settings that are not available in the settings file so don't include settings where a default value would do. Note: This function also queries settings from bear dependencies in recursive manner. Though circular dependency chains are a challenge to achieve, this function would never return on them! :param recurse: Get the settings recursively from its dependencies. :return: A dictionary of needed settings as keys and a tuple of help text and annotation as values. """ non_optional_settings = {} if recurse: for dependency in cls.BEAR_DEPS: non_optional_settings.update( dependency.get_non_optional_settings()) non_optional_settings.update(cls.get_metadata().non_optional_params) return non_optional_settings
[docs] @staticmethod def setup_dependencies(): """ This is a user defined function that can download and set up dependencies (via download_cached_file or arbitrary other means) in an OS independent way. """
[docs] @classmethod def check_prerequisites(cls): """ Checks whether needed runtime prerequisites of the bear are satisfied. This function gets executed at construction. Section value requirements shall be checked inside the ``run`` method. >>> from dependency_management.requirements.PipRequirement import ( ... PipRequirement) >>> class SomeBear(Bear): ... REQUIREMENTS = {PipRequirement('pip')} >>> SomeBear.check_prerequisites() True >>> class SomeOtherBear(Bear): ... REQUIREMENTS = {PipRequirement('really_bad_package')} >>> SomeOtherBear.check_prerequisites() 'really_bad_package is not installed. You can install it using ...' >>> class anotherBear(Bear): ... REQUIREMENTS = {PipRequirement('bad_package', '0.0.1')} >>> anotherBear.check_prerequisites() 'bad_package 0.0.1 is not installed. You can install it using ...' :return: True if prerequisites are satisfied, else False or a string that serves a more detailed description of what's missing. """ for requirement in cls.REQUIREMENTS: if not requirement.is_installed(): return str(requirement) + ' is not installed. You can ' + ( 'install it using ') + ( ' '.join(requirement.install_command())) return True
[docs] def get_config_dir(self): """ Gives the directory where the configuration file is. :return: Directory of the config file. """ return get_config_directory(self.section)
[docs] def download_cached_file(self, url, filename): """ Downloads the file if needed and caches it for the next time. If a download happens, the user will be informed. Take a sane simple bear: >>> from queue import Queue >>> bear = Bear(Section("a section"), Queue()) We can now carelessly query for a neat file that doesn't exist yet: >>> from os import remove >>> if exists(join(bear.data_dir, "a_file")): ... remove(join(bear.data_dir, "a_file")) >>> file = bear.download_cached_file("", "a_file") If we download it again, it'll be much faster as no download occurs: >>> newfile = bear.download_cached_file("", "a_file") >>> newfile == file True :param url: The URL to download the file from. :param filename: The filename it should get, e.g. "test.txt". :return: A full path to the file ready for you to use! """ filename = join(self.data_dir, filename) if exists(filename): return filename'Downloading {filename!r} for bear {bearname} from {url}.' .format(filename=filename,, url=url)) response = requests.get(url, stream=True, timeout=20) response.raise_for_status() with open(filename, 'wb') as file: for chunk in response.iter_content(chunk_size=16 * 1024): file.write(chunk) return filename
@classproperty def data_dir(cls): """ Returns a directory that may be used by the bear to store stuff. Every bear has an own directory dependent on their name. """ data_dir = abspath(join(user_data_dir('coala-bears'), makedirs(data_dir, exist_ok=True) return data_dir @property def new_result(self): """ Returns a partial for creating a result with this bear already bound. """ return partial(Result.from_values, self)