From df22b2b770f6b270bc43f3a487f3af043f183d1d Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Thu, 15 May 2025 00:30:59 +0200
Subject: [PATCH 1/8] Allow different test output for different Python versions

---
 pylint/testutils/functional/test_file.py      | 20 ++++++++++++++++++-
 ... => unnecessary_default_type_args.313.txt} |  0
 .../typing/unnecessary_default_type_args.py   |  4 ++--
 .../typing/unnecessary_default_type_args.rc   |  4 +++-
 .../unnecessary_default_type_args_py313.py    | 17 ----------------
 .../unnecessary_default_type_args_py313.rc    |  3 ---
 6 files changed, 24 insertions(+), 24 deletions(-)
 rename tests/functional/ext/typing/{unnecessary_default_type_args_py313.txt => unnecessary_default_type_args.313.txt} (100%)
 delete mode 100644 tests/functional/ext/typing/unnecessary_default_type_args_py313.py
 delete mode 100644 tests/functional/ext/typing/unnecessary_default_type_args_py313.rc

diff --git a/pylint/testutils/functional/test_file.py b/pylint/testutils/functional/test_file.py
index 37ba3a5fc6..402ee065eb 100644
--- a/pylint/testutils/functional/test_file.py
+++ b/pylint/testutils/functional/test_file.py
@@ -5,6 +5,8 @@
 from __future__ import annotations
 
 import configparser
+import os
+import sys
 from collections.abc import Callable
 from os.path import basename, exists, join
 from typing import TypedDict
@@ -99,7 +101,23 @@ def module(self) -> str:
 
     @property
     def expected_output(self) -> str:
-        return self._file_type(".txt", check_exists=False)
+        files = list(
+            filter(
+                lambda s: s.startswith(f"{self.base}.") and s.endswith(".txt"),
+                os.listdir(self._directory),
+            )
+        )
+        # pylint: disable-next=bad-builtin
+        current_version = int("".join(map(str, sys.version_info[:2])))
+        output_options = [
+            int(version)
+            for s in files
+            if s.count(".") == 2 and (version := s.rsplit(".", maxsplit=2)[1]).isalnum()
+        ]
+        for opt in sorted(output_options, reverse=True):
+            if current_version >= opt:
+                return join(self._directory, f"{self.base}.{opt}.txt")
+        return join(self._directory, self.base + ".txt")
 
     @property
     def source(self) -> str:
diff --git a/tests/functional/ext/typing/unnecessary_default_type_args_py313.txt b/tests/functional/ext/typing/unnecessary_default_type_args.313.txt
similarity index 100%
rename from tests/functional/ext/typing/unnecessary_default_type_args_py313.txt
rename to tests/functional/ext/typing/unnecessary_default_type_args.313.txt
diff --git a/tests/functional/ext/typing/unnecessary_default_type_args.py b/tests/functional/ext/typing/unnecessary_default_type_args.py
index e2d1d700de..7b43e23344 100644
--- a/tests/functional/ext/typing/unnecessary_default_type_args.py
+++ b/tests/functional/ext/typing/unnecessary_default_type_args.py
@@ -3,10 +3,10 @@
 import typing as t
 
 a1: t.Generator[int, str, str]
-a2: t.Generator[int, None, None]
+a2: t.Generator[int, None, None]  # >=3.13:[unnecessary-default-type-args]
 a3: t.Generator[int]
 b1: t.AsyncGenerator[int, str]
-b2: t.AsyncGenerator[int, None]
+b2: t.AsyncGenerator[int, None]  # >=3.13:[unnecessary-default-type-args]
 b3: t.AsyncGenerator[int]
 
 c1: ca.Generator[int, str, str]
diff --git a/tests/functional/ext/typing/unnecessary_default_type_args.rc b/tests/functional/ext/typing/unnecessary_default_type_args.rc
index 63e11a4e6b..910f36995a 100644
--- a/tests/functional/ext/typing/unnecessary_default_type_args.rc
+++ b/tests/functional/ext/typing/unnecessary_default_type_args.rc
@@ -1,3 +1,5 @@
 [main]
-py-version=3.10
 load-plugins=pylint.extensions.typing
+
+[testoptions]
+min_pyver=3.10
diff --git a/tests/functional/ext/typing/unnecessary_default_type_args_py313.py b/tests/functional/ext/typing/unnecessary_default_type_args_py313.py
deleted file mode 100644
index 9dec4c4075..0000000000
--- a/tests/functional/ext/typing/unnecessary_default_type_args_py313.py
+++ /dev/null
@@ -1,17 +0,0 @@
-# pylint: disable=missing-docstring,deprecated-typing-alias
-import collections.abc as ca
-import typing as t
-
-a1: t.Generator[int, str, str]
-a2: t.Generator[int, None, None]  # [unnecessary-default-type-args]
-a3: t.Generator[int]
-b1: t.AsyncGenerator[int, str]
-b2: t.AsyncGenerator[int, None]  # [unnecessary-default-type-args]
-b3: t.AsyncGenerator[int]
-
-c1: ca.Generator[int, str, str]
-c2: ca.Generator[int, None, None]  # [unnecessary-default-type-args]
-c3: ca.Generator[int]
-d1: ca.AsyncGenerator[int, str]
-d2: ca.AsyncGenerator[int, None]  # [unnecessary-default-type-args]
-d3: ca.AsyncGenerator[int]
diff --git a/tests/functional/ext/typing/unnecessary_default_type_args_py313.rc b/tests/functional/ext/typing/unnecessary_default_type_args_py313.rc
deleted file mode 100644
index d2db5fe7ca..0000000000
--- a/tests/functional/ext/typing/unnecessary_default_type_args_py313.rc
+++ /dev/null
@@ -1,3 +0,0 @@
-[main]
-py-version=3.13
-load-plugins=pylint.extensions.typing

From d5019c15c65019fdebc6379d2c5b3fae9b10c629 Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Thu, 15 May 2025 12:20:27 +0200
Subject: [PATCH 2/8] Use pathlib glob for file filter

---
 pylint/testutils/functional/test_file.py | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/pylint/testutils/functional/test_file.py b/pylint/testutils/functional/test_file.py
index 402ee065eb..4a5ce1cf53 100644
--- a/pylint/testutils/functional/test_file.py
+++ b/pylint/testutils/functional/test_file.py
@@ -5,10 +5,10 @@
 from __future__ import annotations
 
 import configparser
-import os
 import sys
 from collections.abc import Callable
 from os.path import basename, exists, join
+from pathlib import Path
 from typing import TypedDict
 
 
@@ -101,18 +101,11 @@ def module(self) -> str:
 
     @property
     def expected_output(self) -> str:
-        files = list(
-            filter(
-                lambda s: s.startswith(f"{self.base}.") and s.endswith(".txt"),
-                os.listdir(self._directory),
-            )
-        )
+        files = [p.stem for p in Path(self._directory).glob(f"{self.base}.[0-9]*.txt")]
         # pylint: disable-next=bad-builtin
         current_version = int("".join(map(str, sys.version_info[:2])))
         output_options = [
-            int(version)
-            for s in files
-            if s.count(".") == 2 and (version := s.rsplit(".", maxsplit=2)[1]).isalnum()
+            int(version) for s in files if (version := s.rpartition(".")[2]).isalnum()
         ]
         for opt in sorted(output_options, reverse=True):
             if current_version >= opt:

From 4cd00adb85a44720ed1ec325c4f5bfeae077102e Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Thu, 15 May 2025 12:39:27 +0200
Subject: [PATCH 3/8] Add changelog and documentation

---
 .../contributor_guide/tests/writing_test.rst  | 21 +++++++++++++++++++
 doc/whatsnew/fragments/10382.internal         |  3 +++
 2 files changed, 24 insertions(+)
 create mode 100644 doc/whatsnew/fragments/10382.internal

diff --git a/doc/development_guide/contributor_guide/tests/writing_test.rst b/doc/development_guide/contributor_guide/tests/writing_test.rst
index 481bd27cef..55822b8c94 100644
--- a/doc/development_guide/contributor_guide/tests/writing_test.rst
+++ b/doc/development_guide/contributor_guide/tests/writing_test.rst
@@ -66,6 +66,27 @@ test runner. The following options are currently supported:
 - "except_implementations": List of python implementations on which the test should not run
 - "exclude_platforms": List of operating systems on which the test should not run
 
+**Different output for different Python versions**
+
+Sometimes the linting result can change between Python releases. In these cases errors can be marked as conditional.
+Supported operators are ``<``, ``<=``, ``>`` and ``>=``.
+
+.. code-block:: python
+
+    def some_func() -> X:  # <3.14:[undefined-variable]
+      ...
+
+    class X: ...
+
+Since the output messages are different, it is necessary to add two separate files for it.
+First ``<test-file-name>.314.txt``, this will include the output messages for ``>=3.14``, i.e. should be empty here.
+Second ``<test-file-name>.txt``, this will be the default for all other Python versions.
+
+.. note::
+
+    This does only work if the code itself is valid in all tested Python versions.
+    For new syntax, use ``min_pyver`` / ``max_pyver`` instead.
+
 **Functional test file locations**
 
 For existing checkers, new test cases should preferably be appended to the existing test file.
diff --git a/doc/whatsnew/fragments/10382.internal b/doc/whatsnew/fragments/10382.internal
new file mode 100644
index 0000000000..126aaf8f87
--- /dev/null
+++ b/doc/whatsnew/fragments/10382.internal
@@ -0,0 +1,3 @@
+Modified test framework to allow for different test output for different Python versions.
+
+Refs #10382

From 5a7ea64418a76ef720cc8461f4333049fd26ef46 Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Thu, 15 May 2025 14:08:28 +0200
Subject: [PATCH 4/8] Fix tests

---
 pylint/testutils/functional/test_file.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/pylint/testutils/functional/test_file.py b/pylint/testutils/functional/test_file.py
index 4a5ce1cf53..8c7057ccbe 100644
--- a/pylint/testutils/functional/test_file.py
+++ b/pylint/testutils/functional/test_file.py
@@ -7,7 +7,7 @@
 import configparser
 import sys
 from collections.abc import Callable
-from os.path import basename, exists, join
+from os.path import basename, exists, join, split
 from pathlib import Path
 from typing import TypedDict
 
@@ -101,7 +101,10 @@ def module(self) -> str:
 
     @property
     def expected_output(self) -> str:
-        files = [p.stem for p in Path(self._directory).glob(f"{self.base}.[0-9]*.txt")]
+        files = [
+            p.stem
+            for p in Path(self._directory).glob(f"{split(self.base)[-1]}.[0-9]*.txt")
+        ]
         # pylint: disable-next=bad-builtin
         current_version = int("".join(map(str, sys.version_info[:2])))
         output_options = [

From d0454ae38ec268b38c12f884e953188f689267ba Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Thu, 15 May 2025 14:15:26 +0200
Subject: [PATCH 5/8] Remove unnecessary testoption

---
 tests/functional/ext/typing/unnecessary_default_type_args.rc | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/tests/functional/ext/typing/unnecessary_default_type_args.rc b/tests/functional/ext/typing/unnecessary_default_type_args.rc
index 910f36995a..825e13ec0b 100644
--- a/tests/functional/ext/typing/unnecessary_default_type_args.rc
+++ b/tests/functional/ext/typing/unnecessary_default_type_args.rc
@@ -1,5 +1,2 @@
 [main]
 load-plugins=pylint.extensions.typing
-
-[testoptions]
-min_pyver=3.10

From 8b71ccc2dd53d0bf80064a3453fa82c400d7a474 Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Mon, 19 May 2025 00:08:13 +0200
Subject: [PATCH 6/8] Add tests and fix edge cases

---
 pylint/testutils/functional/test_file.py     | 15 +++--
 tests/testutils/test_functional_testutils.py | 58 +++++++++++++++++++-
 2 files changed, 66 insertions(+), 7 deletions(-)

diff --git a/pylint/testutils/functional/test_file.py b/pylint/testutils/functional/test_file.py
index 8c7057ccbe..342ced44bf 100644
--- a/pylint/testutils/functional/test_file.py
+++ b/pylint/testutils/functional/test_file.py
@@ -9,7 +9,9 @@
 from collections.abc import Callable
 from os.path import basename, exists, join, split
 from pathlib import Path
-from typing import TypedDict
+from typing import Final, TypedDict
+
+_CURRENT_VERSION: Final = sys.version_info[:2]
 
 
 def parse_python_version(ver_str: str) -> tuple[int, ...]:
@@ -105,14 +107,15 @@ def expected_output(self) -> str:
             p.stem
             for p in Path(self._directory).glob(f"{split(self.base)[-1]}.[0-9]*.txt")
         ]
-        # pylint: disable-next=bad-builtin
-        current_version = int("".join(map(str, sys.version_info[:2])))
         output_options = [
-            int(version) for s in files if (version := s.rpartition(".")[2]).isalnum()
+            (int(version[0]), int(version[1:]))
+            for s in files
+            if (version := s.rpartition(".")[2]).isalnum()
         ]
         for opt in sorted(output_options, reverse=True):
-            if current_version >= opt:
-                return join(self._directory, f"{self.base}.{opt}.txt")
+            if _CURRENT_VERSION >= opt:
+                str_opt = "".join([str(s) for s in opt])
+                return join(self._directory, f"{self.base}.{str_opt}.txt")
         return join(self._directory, self.base + ".txt")
 
     @property
diff --git a/tests/testutils/test_functional_testutils.py b/tests/testutils/test_functional_testutils.py
index d1047c8ee1..6cf0d37c5e 100644
--- a/tests/testutils/test_functional_testutils.py
+++ b/tests/testutils/test_functional_testutils.py
@@ -4,8 +4,13 @@
 
 """Tests for the functional test framework."""
 
+import contextlib
+import os
+import shutil
+import tempfile
+from collections.abc import Iterator
 from pathlib import Path
-from unittest.mock import MagicMock
+from unittest.mock import MagicMock, patch
 
 import pytest
 from _pytest.outcomes import Skipped
@@ -20,6 +25,26 @@
 DATA_DIRECTORY = HERE / "data"
 
 
+@contextlib.contextmanager
+def tempdir() -> Iterator[str]:
+    """Create a temp directory and change the current location to it.
+
+    This is supposed to be used with a *with* statement.
+    """
+    tmp = tempfile.mkdtemp()
+
+    # Get real path of tempfile, otherwise test fail on mac os x
+    current_dir = os.getcwd()
+    os.chdir(tmp)
+    abs_tmp = os.path.abspath(".")
+
+    try:
+        yield abs_tmp
+    finally:
+        os.chdir(current_dir)
+        shutil.rmtree(abs_tmp)
+
+
 @pytest.fixture(name="pytest_config")
 def pytest_config_fixture() -> MagicMock:
     def _mock_getoption(option: str) -> bool:
@@ -69,6 +94,37 @@ def test_get_functional_test_files_from_crowded_directory() -> None:
     assert "max_overflow" not in str(exc_info.value)
 
 
+@pytest.mark.parametrize(
+    ["files", "output_file_name"],
+    [
+        ([], "file.txt"),
+        (["file.txt"], "file.txt"),
+        (["file.314.txt"], "file.txt"),  # don't match 3.14
+        (["file.42.txt"], "file.txt"),  # don't match 4.2
+        (["file.32.txt", "file.txt"], "file.32.txt"),
+        (["file.312.txt", "file.txt"], "file.312.txt"),
+        (["file.313.txt", "file.txt"], "file.313.txt"),
+        (["file.310.txt", "file.313.txt", "file.312.txt", "file.txt"], "file.313.txt"),
+        # don't match other test file names accidentally
+        ([".file.313.txt"], "file.txt"),
+        (["file_other.313.txt"], "file.txt"),
+        (["other_file.313.txt"], "file.txt"),
+    ],
+)
+def test_expected_output_file_matching(files: list[str], output_file_name: str) -> None:
+    """Test output file matching. Pin current Python version to 3.13."""
+    with tempdir():
+        for file in files:
+            with open(file, "w", encoding="utf-8"):
+                ...
+        test_file = FunctionalTestFile(".", "file.py")
+        with patch(
+            "pylint.testutils.functional.test_file._CURRENT_VERSION",
+            new=(3, 13),
+        ):
+            assert test_file.expected_output == f"./{output_file_name}"
+
+
 def test_minimal_messages_config_enabled(pytest_config: MagicMock) -> None:
     """Test that all messages not targeted in the functional test are disabled
     when running with --minimal-messages-config.

From e2528113d2de537d90aefd032e961740815bd6d4 Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Mon, 19 May 2025 00:15:19 +0200
Subject: [PATCH 7/8] Improve documentation

---
 .../contributor_guide/tests/writing_test.rst               | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/doc/development_guide/contributor_guide/tests/writing_test.rst b/doc/development_guide/contributor_guide/tests/writing_test.rst
index 55822b8c94..5c31075d4a 100644
--- a/doc/development_guide/contributor_guide/tests/writing_test.rst
+++ b/doc/development_guide/contributor_guide/tests/writing_test.rst
@@ -76,6 +76,11 @@ Supported operators are ``<``, ``<=``, ``>`` and ``>=``.
     def some_func() -> X:  # <3.14:[undefined-variable]
       ...
 
+    # It can also be combined with offsets
+    # +1:<3.14:[undefined-variable]
+    def some_other_func() -> X:
+      ...
+
     class X: ...
 
 Since the output messages are different, it is necessary to add two separate files for it.
@@ -84,7 +89,7 @@ Second ``<test-file-name>.txt``, this will be the default for all other Python v
 
 .. note::
 
-    This does only work if the code itself is valid in all tested Python versions.
+    This does only work if the code itself is parsable in all tested Python versions.
     For new syntax, use ``min_pyver`` / ``max_pyver`` instead.
 
 **Functional test file locations**

From 6a530b9d747ec9da1dcb8d395b518501df55be18 Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Mon, 19 May 2025 00:36:07 +0200
Subject: [PATCH 8/8] Fix windows tests

---
 tests/testutils/test_functional_testutils.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/testutils/test_functional_testutils.py b/tests/testutils/test_functional_testutils.py
index 6cf0d37c5e..0d332f02d9 100644
--- a/tests/testutils/test_functional_testutils.py
+++ b/tests/testutils/test_functional_testutils.py
@@ -6,6 +6,7 @@
 
 import contextlib
 import os
+import os.path
 import shutil
 import tempfile
 from collections.abc import Iterator
@@ -122,7 +123,7 @@ def test_expected_output_file_matching(files: list[str], output_file_name: str)
             "pylint.testutils.functional.test_file._CURRENT_VERSION",
             new=(3, 13),
         ):
-            assert test_file.expected_output == f"./{output_file_name}"
+            assert test_file.expected_output == f".{os.path.sep}{output_file_name}"
 
 
 def test_minimal_messages_config_enabled(pytest_config: MagicMock) -> None: