Read additional args from file with with @<path>.

Author: julian-smith-artifex-com

README.rst

@@ -229,6 +229,13 @@ instead of these invalid entries:
 
 .. _tomli: https://pypi.org/project/tomli/
 
+Reading arguments from file
+---------------------------
+
+Additional arguments can be read from a file with ``@PATH``. Arguments are
+extracted using ``shlex.split()``.
+
+
 pre-commit hook
 ---------------
 

codespell_lib/_codespell.py

@@ -23,6 +23,7 @@
 import itertools
 import os
 import re
+import shlex
 import sys
 import textwrap
 from collections.abc import Iterable, Sequence
@@ -388,7 +389,20 @@ def _supports_ansi_colors() -> bool:
 def parse_options(
     args: Sequence[str],
 ) -> tuple[argparse.Namespace, argparse.ArgumentParser, list[str]]:
-    parser = argparse.ArgumentParser(formatter_class=NewlineHelpFormatter)
+
+    # Split lines read from `@PATH` using shlex.split(), otherwise default
+    # behaviour is to have one arg per line. See: 
+    # https://docs.python.org/3/library/argparse.html#argparse.ArgumentParser.convert_arg_line_to_args
+    class ArgumentParser(argparse.ArgumentParser):
+        def convert_arg_line_to_args(self, arg_line: str
+        ) -> list[str]:
+            return shlex.split(arg_line)
+    
+    parser = ArgumentParser(
+        formatter_class=NewlineHelpFormatter,
+        fromfile_prefix_chars="@",
+        epilog="Use @PATH to read additional arguments from file PATH.",
+    )
 
     parser.set_defaults(colors=_supports_ansi_colors())
     parser.add_argument("--version", action="version", version=VERSION)

codespell_lib/tests/test_basic.py

@@ -1458,3 +1458,25 @@ def test_stdin(tmp_path: Path, capsys: pytest.CaptureFixture[str]) -> None:
         code, stdout, _ = result
         assert stdout == "1: Thsi ==> This\n"
         assert code == 1
+
+def test_args_from_file(
+    tmp_path: Path,
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    fname1 = tmp_path / "tmp1"
+    fname2 = tmp_path / "tmp2"
+    fname3 = tmp_path / "tmp3"
+    fname_list = tmp_path / "tmp_list"
+    fname_list.write_text(f"{fname1} {fname2}\n{fname3}")
+    fname1.write_text("abandonned\ncode")
+    fname2.write_text("exmaple\n")
+    fname3.write_text("abilty\n")
+    print(f'@{fname_list}')
+    result = cs.main(f"@{fname_list}", std=True)
+    assert isinstance(result, tuple)
+    code, stdout, stderr = result
+    print(f"{code=} {stdout=} {stderr=}")
+    assert "tmp1:1: abandonned ==> abandoned\n" in stdout, f"{stdout=}"
+    assert "tmp2:1: exmaple ==> example\n" in stdout, f"{stdout=}"
+    assert "tmp3:1: abilty ==> ability\n" in stdout, f"{stdout=}"
+    assert code == 3, f"{code=}"