From a1b5e5ce7b70956adf6a7539e86a02ee84d4c8c0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dani=C3=ABl=20van=20Noord?=
 <13665637+DanielNoord@users.noreply.github.com>
Date: Wed, 22 Dec 2021 09:55:54 +0100
Subject: [PATCH] Make ``PyLinter`` subclass ``ArgumentsManager`` and add tests

---
 pylint/lint/pylinter.py              |  3 +++
 tests/config/test_argparse_config.py | 23 +++++++++++++++++++++++
 tests/test_regr.py                   |  1 +
 3 files changed, 27 insertions(+)
 create mode 100644 tests/config/test_argparse_config.py

diff --git a/pylint/lint/pylinter.py b/pylint/lint/pylinter.py
index 023455f68e4..472ed893169 100644
--- a/pylint/lint/pylinter.py
+++ b/pylint/lint/pylinter.py
@@ -1,6 +1,7 @@
 # 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
 
+import argparse
 import collections
 import contextlib
 import functools
@@ -192,6 +193,7 @@ class PyLinter(
     config.OptionsManagerMixIn,
     reporters.ReportsHandlerMixIn,
     checkers.BaseTokenChecker,
+    config._ArgumentsManager,
 ):
     """lint Python modules using external checkers.
 
@@ -600,6 +602,7 @@ def __init__(
         self._by_id_managed_msgs: List[ManagedMessage] = []
 
         reporters.ReportsHandlerMixIn.__init__(self)
+        config._ArgumentsManager.__init__(self, argparse.Namespace())
         super().__init__(
             usage=__doc__,
             config_file=pylintrc or next(config.find_default_config_files(), None),
diff --git a/tests/config/test_argparse_config.py b/tests/config/test_argparse_config.py
new file mode 100644
index 00000000000..a44eb7ff349
--- /dev/null
+++ b/tests/config/test_argparse_config.py
@@ -0,0 +1,23 @@
+"""Test for the (new) implementation of option parsing with argparse"""
+
+import argparse
+
+from pylint import config
+from pylint.lint import PyLinter
+
+
+class TestArgumentsManager:
+    """Tests for the ArgumentsManager class"""
+
+    @staticmethod
+    def test_initialize_arguments_manager_class(linter: PyLinter) -> None:
+        """Tests that ArgumentsManager is correctly initialized on a PyLinter class"""
+        assert isinstance(linter, config._ArgumentsManager)
+        assert isinstance(linter.namespace, argparse.Namespace)
+
+    @staticmethod
+    def test_help_message(linter: PyLinter) -> None:
+        """Test the help_message attribute of the ArgumentsManager class"""
+        assert isinstance(linter.help_message, str)
+        lines = linter.help_message.splitlines()
+        assert lines[0] == "usage: pylint [-h]"
diff --git a/tests/test_regr.py b/tests/test_regr.py
index 99b60027550..fc377af2c51 100644
--- a/tests/test_regr.py
+++ b/tests/test_regr.py
@@ -145,6 +145,7 @@ def test_pylint_config_attr() -> None:
         "BaseTokenChecker",
         "BaseChecker",
         "OptionsProviderMixIn",
+        "_ArgumentsManager",
     ]
     assert [c.name for c in pylinter.ancestors()] == expect
     assert list(astroid.Instance(pylinter).getattr("config"))