Add option to allow overriding isort's skip_gitignore option

CHANGES.rst

@@ -3,12 +3,17 @@
 Changelog
 =========
 
-5.0.4 (unreleased)
+5.1.0 (unreleased)
 ------------------
 
 - Drop isort 4.x support.
   [gforcada]
 
+- Add `--isort-no-skip-gitignore` option to allow temporarily overriding the set
+  value of isort's `skip_gitignore` option with `False`. This can cause
+  flake8-isort to run significantly faster at the cost of making flake8-isort's
+  behavior differ slightly from the behavior of `isort --check`. [gschaffner]
+
 5.0.3 (2022-11-20)
 ------------------
 

README.rst

@@ -29,6 +29,8 @@ Configuration
 -------------
 If using the `select` `option from flake8`_ be sure to enable the `I` category as well, see below for the specific error codes reported by `flake8-isort`.
 
+See ``flake8 --help`` for available flake8-isort options.
+
 Error codes
 -----------
 +------------+-----------------------------------------------------------+

flake8_isort.py

@@ -25,6 +25,7 @@ class Flake8IsortBase:
     isort_add_unexp = 'I005 isort found an unexpected missing import'
 
     show_traceback = False
+    no_skip_gitignore = False
     stdin_display_name = None
     search_current = True
 
@@ -40,11 +41,23 @@ def add_options(option_manager):
             parse_from_config=True,
             help='Show full traceback with diff from isort',
         )
+        option_manager.add_option(
+            '--isort-no-skip-gitignore',
+            action='store_true',
+            parse_from_config=True,
+            help=(
+                "Temporarily override the set value of isort's `skip_gitignore` option "
+                'with `False`. This can cause flake8-isort to run significantly faster '
+                "at the cost of making flake8-isort's behavior differ slightly from "
+                'the behavior of `isort --check`.'
+            ),
+        )
 
     @classmethod
     def parse_options(cls, option_manager, options, args):
         cls.stdin_display_name = options.stdin_display_name
         cls.show_traceback = options.isort_show_traceback
+        cls.no_skip_gitignore = options.isort_no_skip_gitignore
 
 
 class Flake8Isort5(Flake8IsortBase):
@@ -53,10 +66,16 @@ class Flake8Isort5(Flake8IsortBase):
     def run(self):
         if self.filename is not self.stdin_display_name:
             file_path = Path(self.filename)
-            isort_config = isort.settings.Config(settings_path=file_path.parent)
+            settings_path = file_path.parent
         else:
             file_path = None
-            isort_config = isort.settings.Config(settings_path=Path.cwd())
+            settings_path = Path.cwd()
+        if self.no_skip_gitignore:
+            isort_config = isort.settings.Config(
+                settings_path=settings_path, skip_gitignore=False
+            )
+        else:
+            isort_config = isort.settings.Config(settings_path=settings_path)
         input_string = ''.join(self.lines)
         traceback = ''
         isort_changed = False

run_tests.py

@@ -212,15 +212,21 @@ def test_isort_formatted_output(tmpdir):
     from sys import pid
     """
     options = collections.namedtuple(
-        'Options', ['no_isort_config', 'isort_show_traceback', 'stdin_display_name']
+        'Options',
+        [
+            'no_isort_config',
+            'isort_show_traceback',
+            'stdin_display_name',
+            'isort_no_skip_gitignore',
+        ],
     )
 
     (file_path, lines) = write_python_file(tmpdir, source)
 
     diff = ' from __future__ import division\n+\n import os'
 
     checker = Flake8Isort(None, file_path, lines)
-    checker.parse_options(None, options(None, True, 'stdin'), None)
+    checker.parse_options(None, options(None, True, 'stdin', None), None)
     ret = list(checker.run())
     assert len(ret) == 1
     assert ret[0][0] == 3

setup.py

@@ -17,7 +17,7 @@ def read_file(filename):
 
 setup(
     name='flake8-isort',
-    version='5.0.4.dev0',
+    version='5.1.0.dev0',
     description=short_description,
     long_description=long_description,
     # Get more from https://pypi.org/classifiers/