From c34fd755f06eb06a78bcfcedf8b74aecbc7e801e Mon Sep 17 00:00:00 2001
From: Buck Evan <buck.evan@sentry.io>
Date: Tue, 20 Dec 2022 12:28:52 -0600
Subject: [PATCH] allow idiomatic setup.cfg comments

---
 src/flake8/utils.py               | 5 +++--
 tests/unit/test_options_config.py | 9 +++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/flake8/utils.py b/src/flake8/utils.py
index afc3896..8509d6c 100644
--- a/src/flake8/utils.py
+++ b/src/flake8/utils.py
@@ -17,7 +17,8 @@ from typing import Sequence
 
 from flake8 import exceptions
 
-COMMA_SEPARATED_LIST_RE = re.compile(r"[,\s]")
+COMMA_SEPARATED_LIST_RE = re.compile(r"[,\s]+")
+STRIP_RE = re.compile(r"^\s+|\s+$|\s*#.*$")
 LOCAL_PLUGIN_LIST_RE = re.compile(r"[,\t\n\r\f\v]")
 NORMALIZE_PACKAGE_NAME_RE = re.compile(r"[-_.]+")
 
@@ -38,7 +39,7 @@ def parse_comma_separated_list(
     assert isinstance(value, str), value
 
     separated = regexp.split(value)
-    item_gen = (item.strip() for item in separated)
+    item_gen = (STRIP_RE.sub("", item) for item in separated)
     return [item for item in item_gen if item]
 
 
diff --git a/tests/unit/test_options_config.py b/tests/unit/test_options_config.py
index 7de58f0..05f27ad 100644
--- a/tests/unit/test_options_config.py
+++ b/tests/unit/test_options_config.py
@@ -243,6 +243,15 @@ def test_invalid_ignore_codes_raise_error(tmpdir, opt_manager):
     assert msg == expected
 
 
+def test_ignore_code_comments_dont_raise_error(tmpdir, opt_manager):
+    tmpdir.join("setup.cfg").write("[flake8]\nignore = E203, #comment")
+    with tmpdir.as_cwd():
+        cfg, _ = config.load_config("setup.cfg", [], isolated=False)
+
+    ret = config.parse_config(opt_manager, cfg, tmpdir)
+    assert ret == {"ignore": ["E203"]}
+
+
 def test_invalid_extend_ignore_codes_raise_error(tmpdir, opt_manager):
     tmpdir.join("setup.cfg").write("[flake8]\nextend-ignore = E203, //comment")
     with tmpdir.as_cwd():