Source code for flake8.main.application

"""Module containing the application logic for Flake8."""
import argparse
import configparser
import logging
import sys
import time
from typing import Dict
from typing import List
from typing import Optional
from typing import Sequence
from typing import Set
from typing import Tuple
from typing import Type
from typing import TYPE_CHECKING

import flake8
from flake8 import checker
from flake8 import defaults
from flake8 import exceptions
from flake8 import style_guide
from flake8 import utils
from flake8.main import options
from flake8.options import aggregator
from flake8.options import config
from flake8.options import manager
from flake8.plugins import manager as plugin_manager

if TYPE_CHECKING:
    from flake8.formatting.base import BaseFormatter


LOG = logging.getLogger(__name__)


[docs]class Application: """Abstract our application into a class.""" def __init__(self, program="flake8", version=flake8.__version__): """Initialize our application. :param str program: The name of the program/application that we're executing. :param str version: The version of the program/application we're executing. """ #: The timestamp when the Application instance was instantiated. self.start_time = time.time() #: The timestamp when the Application finished reported errors. self.end_time: Optional[float] = None #: The name of the program being run self.program = program #: The version of the program being run self.version = version #: The prelimary argument parser for handling options required for #: obtaining and parsing the configuration file. self.prelim_arg_parser = argparse.ArgumentParser(add_help=False) options.register_preliminary_options(self.prelim_arg_parser) #: The instance of :class:`flake8.options.manager.OptionManager` used #: to parse and handle the options and arguments passed by the user self.option_manager = manager.OptionManager( prog="flake8", version=flake8.__version__, parents=[self.prelim_arg_parser], ) options.register_default_options(self.option_manager) #: The instance of :class:`flake8.plugins.manager.Checkers` self.check_plugins: Optional[plugin_manager.Checkers] = None #: The instance of :class:`flake8.plugins.manager.ReportFormatters` self.formatting_plugins: Optional[ plugin_manager.ReportFormatters ] = None #: The user-selected formatter from :attr:`formatting_plugins` self.formatter: Optional[BaseFormatter] = None #: The :class:`flake8.style_guide.StyleGuideManager` built from the #: user's options self.guide: Optional[style_guide.StyleGuideManager] = None #: The :class:`flake8.checker.Manager` that will handle running all of #: the checks selected by the user. self.file_checker_manager: Optional[checker.Manager] = None #: The user-supplied options parsed into an instance of #: :class:`argparse.Namespace` self.options: Optional[argparse.Namespace] = None #: The number of errors, warnings, and other messages after running #: flake8 and taking into account ignored errors and lines. self.result_count = 0 #: The total number of errors before accounting for ignored errors and #: lines. self.total_result_count = 0 #: Whether or not something catastrophic happened and we should exit #: with a non-zero status code self.catastrophic_failure = False #: The parsed diff information self.parsed_diff: Dict[str, Set[int]] = {}
[docs] def parse_preliminary_options( self, argv: Sequence[str] ) -> Tuple[argparse.Namespace, List[str]]: """Get preliminary options from the CLI, pre-plugin-loading. We need to know the values of a few standard options so that we can locate configuration files and configure logging. Since plugins aren't loaded yet, there may be some as-yet-unknown options; we ignore those for now, they'll be parsed later when we do real option parsing. :param list argv: Command-line arguments passed in directly. :returns: Populated namespace and list of remaining argument strings. :rtype: (argparse.Namespace, list) """ args, rest = self.prelim_arg_parser.parse_known_args(argv) # XXX (ericvw): Special case "forwarding" the output file option so # that it can be reparsed again for the BaseFormatter.filename. if args.output_file: rest.extend(("--output-file", args.output_file)) return args, rest
[docs] def exit_code(self) -> int: """Return the program exit code.""" assert self.options is not None if self.options.exit_zero: return int(self.catastrophic_failure) else: return int((self.result_count > 0) or self.catastrophic_failure)
[docs] def find_plugins( self, cfg: configparser.RawConfigParser, cfg_dir: str, ) -> None: """Find and load the plugins for this application. Set the :attr:`check_plugins` and :attr:`formatting_plugins` attributes based on the discovered plugins found. """ # TODO: move to src/flake8/plugins/finder.py extension_local = utils.parse_comma_separated_list( cfg.get("flake8:local-plugins", "extension", fallback="").strip(), regexp=utils.LOCAL_PLUGIN_LIST_RE, ) report_local = utils.parse_comma_separated_list( cfg.get("flake8:local-plugins", "report", fallback="").strip(), regexp=utils.LOCAL_PLUGIN_LIST_RE, ) paths_s = cfg.get("flake8:local-plugins", "paths", fallback="").strip() local_paths = utils.parse_comma_separated_list(paths_s) local_paths = utils.normalize_paths(local_paths, cfg_dir) sys.path.extend(local_paths) self.check_plugins = plugin_manager.Checkers(extension_local) self.formatting_plugins = plugin_manager.ReportFormatters(report_local) self.check_plugins.load_plugins() self.formatting_plugins.load_plugins()
[docs] def register_plugin_options(self) -> None: """Register options provided by plugins to our option manager.""" assert self.check_plugins is not None self.check_plugins.register_options(self.option_manager) self.check_plugins.register_plugin_versions(self.option_manager) assert self.formatting_plugins is not None self.formatting_plugins.register_options(self.option_manager)
[docs] def parse_configuration_and_cli( self, cfg: configparser.RawConfigParser, cfg_dir: str, argv: List[str], ) -> None: """Parse configuration files and the CLI options.""" self.options = aggregator.aggregate_options( self.option_manager, cfg, cfg_dir, argv, ) if self.options.diff: LOG.warning( "the --diff option is deprecated and will be removed in a " "future version." ) self.parsed_diff = utils.parse_unified_diff() assert self.check_plugins is not None self.check_plugins.provide_options( self.option_manager, self.options, self.options.filenames ) assert self.formatting_plugins is not None self.formatting_plugins.provide_options( self.option_manager, self.options, self.options.filenames )
[docs] def formatter_for(self, formatter_plugin_name): """Retrieve the formatter class by plugin name.""" assert self.formatting_plugins is not None default_formatter = self.formatting_plugins["default"] formatter_plugin = self.formatting_plugins.get(formatter_plugin_name) if formatter_plugin is None: LOG.warning( '"%s" is an unknown formatter. Falling back to default.', formatter_plugin_name, ) formatter_plugin = default_formatter return formatter_plugin.execute
[docs] def make_formatter( self, formatter_class: Optional[Type["BaseFormatter"]] = None ) -> None: """Initialize a formatter based on the parsed options.""" assert self.options is not None format_plugin = self.options.format if 1 <= self.options.quiet < 2: format_plugin = "quiet-filename" elif 2 <= self.options.quiet: format_plugin = "quiet-nothing" if formatter_class is None: formatter_class = self.formatter_for(format_plugin) self.formatter = formatter_class(self.options)
[docs] def make_guide(self) -> None: """Initialize our StyleGuide.""" assert self.formatter is not None assert self.options is not None self.guide = style_guide.StyleGuideManager( self.options, self.formatter ) if self.options.diff: self.guide.add_diff_ranges(self.parsed_diff)
[docs] def make_file_checker_manager(self) -> None: """Initialize our FileChecker Manager.""" self.file_checker_manager = checker.Manager( style_guide=self.guide, checker_plugins=self.check_plugins, )
[docs] def run_checks(self) -> None: """Run the actual checks with the FileChecker Manager. This method encapsulates the logic to make a :class:`~flake8.checker.Manger` instance run the checks it is managing. """ assert self.options is not None assert self.file_checker_manager is not None if self.options.diff: files: Optional[List[str]] = sorted(self.parsed_diff) if not files: return else: files = None self.file_checker_manager.start(files) try: self.file_checker_manager.run() except exceptions.PluginExecutionFailed as plugin_failed: print(str(plugin_failed)) print("Run flake8 with greater verbosity to see more details") self.catastrophic_failure = True LOG.info("Finished running") self.file_checker_manager.stop() self.end_time = time.time()
[docs] def report_benchmarks(self) -> None: """Aggregate, calculate, and report benchmarks for this run.""" assert self.options is not None if not self.options.benchmark: return assert self.file_checker_manager is not None assert self.end_time is not None time_elapsed = self.end_time - self.start_time statistics = [("seconds elapsed", time_elapsed)] add_statistic = statistics.append for statistic in defaults.STATISTIC_NAMES + ("files",): value = self.file_checker_manager.statistics[statistic] total_description = f"total {statistic} processed" add_statistic((total_description, value)) per_second_description = f"{statistic} processed per second" add_statistic((per_second_description, int(value / time_elapsed))) assert self.formatter is not None self.formatter.show_benchmarks(statistics)
[docs] def report_errors(self) -> None: """Report all the errors found by flake8 3.0. This also updates the :attr:`result_count` attribute with the total number of errors, warnings, and other messages found. """ LOG.info("Reporting errors") assert self.file_checker_manager is not None results = self.file_checker_manager.report() self.total_result_count, self.result_count = results LOG.info( "Found a total of %d violations and reported %d", self.total_result_count, self.result_count, )
[docs] def report_statistics(self) -> None: """Aggregate and report statistics from this run.""" assert self.options is not None if not self.options.statistics: return assert self.formatter is not None assert self.guide is not None self.formatter.show_statistics(self.guide.stats)
[docs] def initialize(self, argv: Sequence[str]) -> None: """Initialize the application to be run. This finds the plugins, registers their options, and parses the command-line arguments. """ # NOTE(sigmavirus24): When updating this, make sure you also update # our legacy API calls to these same methods. prelim_opts, remaining_args = self.parse_preliminary_options(argv) flake8.configure_logging(prelim_opts.verbose, prelim_opts.output_file) cfg, cfg_dir = config.load_config( config=prelim_opts.config, extra=prelim_opts.append_config, isolated=prelim_opts.isolated, ) self.find_plugins(cfg, cfg_dir) self.register_plugin_options() self.parse_configuration_and_cli(cfg, cfg_dir, remaining_args) self.make_formatter() self.make_guide() self.make_file_checker_manager()
[docs] def report(self) -> None: """Report errors, statistics, and benchmarks.""" assert self.formatter is not None self.formatter.start() self.report_errors() self.report_statistics() self.report_benchmarks() self.formatter.stop()
def _run(self, argv: Sequence[str]) -> None: self.initialize(argv) self.run_checks() self.report()
[docs] def run(self, argv: Sequence[str]) -> None: """Run our application. This method will also handle KeyboardInterrupt exceptions for the entirety of the flake8 application. If it sees a KeyboardInterrupt it will forcibly clean up the :class:`~flake8.checker.Manager`. """ try: self._run(argv) except KeyboardInterrupt as exc: print("... stopped") LOG.critical("Caught keyboard interrupt from user") LOG.exception(exc) self.catastrophic_failure = True except exceptions.ExecutionError as exc: print("There was a critical error during execution of Flake8:") print(exc) LOG.exception(exc) self.catastrophic_failure = True except exceptions.EarlyQuit: self.catastrophic_failure = True print("... stopped while processing files") assert self.options is not None if self.options.count: print(self.result_count)