Apply suggestions from code review

Co-authored-by: Taneli Hukkinen <[email protected]>

src/mdformat/_cli.py

@@ -203,9 +203,9 @@ def make_arg_parser(
     )
     parser.add_argument(
         "--no-validate",
-        action="store_false",
+        action="store_const",
+        const=False,
         dest="validate",
-        default=None,
         help="do not validate that the rendered HTML is consistent",
     )
     version_str = f"mdformat {mdformat.__version__}"

tests/test_config_file.py

@@ -1,7 +1,6 @@
 from io import StringIO
 import sys
 from unittest import mock
-from unittest.mock import patch
 
 import pytest
 
@@ -158,7 +157,7 @@ def test_conf_no_validate(tmp_path):
     content = "1. ordered"
     file_path.write_text(content)
 
-    with patch("mdformat.renderer._context.get_list_marker_type", return_value="?"):
+    with mock.patch("mdformat.renderer._context.get_list_marker_type", return_value="?"):
         assert run_with_clear_cache((str(file_path),)) == 1
         assert file_path.read_text() == content