Fix inconsistent argument exit code when argparse exit with its own e…

…rror code (#7931) (#7943)

Returning 2 here is confusing as it doesn't match the documentation: https://pylint.pycqa.org/en/latest/user_guide/usage/run.html#exit-codes

* pylint: use exit code 32 when invalid arguments are passed

* pylint: add failing test when ambiguous abbreviated parameters are set in a config file

This is confusing behaviour. The output is:

```
usage: pylint [options]
pylint: error: ambiguous option: --no could match --notes, --notes-rgx, --no-docstring-rgx
```

The exit code is 2 which doesn't match the documentation: https://pylint.pycqa.org/en/latest/user_guide/usage/run.html#exit-codes

* pylint: use exit code 32 when ambiguous abbreviated parameters are set in a config file

Co-authored-by: Pierre Sassoulas <[email protected]>
(cherry picked from commit 62232b3)

Co-authored-by: David Lawson <[email protected]>

doc/whatsnew/fragments/7931.bugfix

@@ -0,0 +1,3 @@
+When pylint exit due to bad arguments being provided the exit code will now be the expected ``32``.
+
+Refs #7931

pylint/config/arguments_manager.py

@@ -252,9 +252,12 @@ def _load_default_argument_values(self) -> None:
 
     def _parse_configuration_file(self, arguments: list[str]) -> None:
         """Parse the arguments found in a configuration file into the namespace."""
-        self.config, parsed_args = self._arg_parser.parse_known_args(
-            arguments, self.config
-        )
+        try:
+            self.config, parsed_args = self._arg_parser.parse_known_args(
+                arguments, self.config
+            )
+        except SystemExit:
+            sys.exit(32)
         unrecognized_options: list[str] = []
         for opt in parsed_args:
             if opt.startswith("--"):

pylint/config/config_initialization.py

@@ -87,7 +87,10 @@ def _config_initialization(
             unrecognized_options.append(opt[1:])
     if unrecognized_options:
         msg = ", ".join(unrecognized_options)
-        linter._arg_parser.error(f"Unrecognized option found: {msg}")
+        try:
+            linter._arg_parser.error(f"Unrecognized option found: {msg}")
+        except SystemExit:
+            sys.exit(32)
 
     # Now that config file and command line options have been loaded
     # with all disables, it is safe to emit messages

tests/lint/test_run_pylint.py

@@ -0,0 +1,36 @@
+# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+# For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
+# Copyright (c) https://github.com/PyCQA/pylint/blob/main/CONTRIBUTORS.txt
+
+from pathlib import Path
+
+import pytest
+from _pytest.capture import CaptureFixture
+
+from pylint import run_pylint
+
+
+def test_run_pylint_with_invalid_argument(capsys: CaptureFixture[str]) -> None:
+    """Check that appropriate exit code is used with invalid argument."""
+    with pytest.raises(SystemExit) as ex:
+        run_pylint(["--never-use-this"])
+    captured = capsys.readouterr()
+    assert captured.err.startswith("usage: pylint [options]")
+    assert ex.value.code == 32
+
+
+def test_run_pylint_with_invalid_argument_in_config(
+    capsys: CaptureFixture[str], tmp_path: Path
+) -> None:
+    """Check that appropriate exit code is used with an ambiguous
+    argument in a config file.
+    """
+    test_file = tmp_path / "testpylintrc"
+    with open(test_file, "w", encoding="utf-8") as f:
+        f.write("[MASTER]\nno=")
+
+    with pytest.raises(SystemExit) as ex:
+        run_pylint(["--rcfile", f"{test_file}"])
+    captured = capsys.readouterr()
+    assert captured.err.startswith("usage: pylint [options]")
+    assert ex.value.code == 32

tests/lint/unittest_expand_modules.py

@@ -69,6 +69,14 @@ def test__is_in_ignore_list_re_match() -> None:
     "path": str(TEST_DIRECTORY / "lint/test_utils.py"),
 }
 
+test_run_pylint = {
+    "basename": "lint",
+    "basepath": INIT_PATH,
+    "isarg": False,
+    "name": "lint.test_run_pylint",
+    "path": str(TEST_DIRECTORY / "lint/test_run_pylint.py"),
+}
+
 test_pylinter = {
     "basename": "lint",
     "basepath": INIT_PATH,
@@ -102,6 +110,7 @@ def _list_expected_package_modules(
         init_of_package,
         test_caching,
         test_pylinter,
+        test_run_pylint,
         test_utils,
         this_file_from_init_deduplicated if deduplicating else this_file_from_init,
         unittest_lint,