use return value of parse_args directly

src/flake8/main/application.py

@@ -80,9 +80,6 @@ class Application:
         #: The user-supplied options parsed into an instance of
         #: :class:`argparse.Namespace`
         self.options: Optional[argparse.Namespace] = None
-        #: The left over arguments that were not parsed by
-        #: :attr:`option_manager`
-        self.args: Optional[List[str]] = None
         #: The number of errors, warnings, and other messages after running
         #: flake8 and taking into account ignored errors and lines.
         self.result_count = 0
@@ -183,7 +180,7 @@ class Application:
         :param list argv:
             Command-line arguments passed in directly.
         """
-        self.options, self.args = aggregator.aggregate_options(
+        self.options = aggregator.aggregate_options(
             self.option_manager,
             config_finder,
             argv,
@@ -201,11 +198,11 @@ class Application:
 
         assert self.check_plugins is not None
         self.check_plugins.provide_options(
-            self.option_manager, self.options, self.args
+            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.args
+            self.option_manager, self.options, self.options.filenames
         )
 
     def formatter_for(self, formatter_plugin_name):
@@ -251,9 +248,10 @@ class Application:
 
     def make_file_checker_manager(self) -> None:
         """Initialize our FileChecker Manager."""
+        assert self.options is not None
         self.file_checker_manager = checker.Manager(
             style_guide=self.guide,
-            arguments=self.args,
+            arguments=self.options.filenames,
             checker_plugins=self.check_plugins,
         )
 

src/flake8/options/aggregator.py

@@ -6,7 +6,6 @@ applies the user-specified command-line configuration on top of it.
 import argparse
 import logging
 from typing import List
-from typing import Tuple
 
 from flake8.options import config
 from flake8.options.manager import OptionManager
@@ -18,7 +17,7 @@ def aggregate_options(
     manager: OptionManager,
     config_finder: config.ConfigFileFinder,
     argv: List[str],
-) -> Tuple[argparse.Namespace, List[str]]:
+) -> argparse.Namespace:
     """Aggregate and merge CLI and config file options.
 
     :param flake8.options.manager.OptionManager manager:
@@ -35,7 +34,7 @@ def aggregate_options(
         tuple(argparse.Namespace, list)
     """
     # Get defaults from the option parser
-    default_values, _ = manager.parse_args([])
+    default_values = manager.parse_args([])
 
     # Make our new configuration file mergerator
     config_parser = config.ConfigParser(

src/flake8/options/manager.py

@@ -459,15 +459,13 @@ class OptionManager:
         self,
         args: Optional[List[str]] = None,
         values: Optional[argparse.Namespace] = None,
-    ) -> Tuple[argparse.Namespace, List[str]]:
+    ) -> argparse.Namespace:
         """Proxy to calling the OptionParser's parse_args method."""
         self.generate_epilog()
         self.update_version_string()
         if values:
             self.parser.set_defaults(**vars(values))
-        parsed_args = self.parser.parse_args(args)
-        # TODO: refactor callers to not need this
-        return parsed_args, parsed_args.filenames
+        return self.parser.parse_args(args)
 
     def parse_known_args(
         self, args: Optional[List[str]] = None