[deprecation] Remove the warning about the old pylint home

doc/whatsnew/fragments/8462.breaking

@@ -0,0 +1,5 @@
+The warning when the now useless old pylint cache directory (pylint.d) was
+found was removed. The cache dir is documented in
+[the FAQ](https://pylint.readthedocs.io/en/latest/faq.html#where-is-the-persistent-data-stored-to-compare-between-successive-runs).
+
+Refs #8462

pylint/config/help_formatter.py

@@ -7,7 +7,7 @@
 import argparse
 
 from pylint.config.callback_actions import _CallbackAction
-from pylint.constants import DEFAULT_PYLINT_HOME, OLD_DEFAULT_PYLINT_HOME
+from pylint.constants import DEFAULT_PYLINT_HOME
 
 
 class _HelpFormatter(argparse.RawDescriptionHelpFormatter):
@@ -35,8 +35,7 @@ def get_long_description() -> str:
 Environment variables:
     The following environment variables are used:
         * PYLINTHOME    Path to the directory where persistent data for the run will
-                        be stored. If not found, it defaults to '{DEFAULT_PYLINT_HOME}'
-                        or '{OLD_DEFAULT_PYLINT_HOME}' (in the current working directory).
+                        be stored. If not found, it defaults to '{DEFAULT_PYLINT_HOME}'.
         * PYLINTRC      Path to the configuration file. See the documentation for the method used
                         to search for configuration file.
 

pylint/constants.py

@@ -5,10 +5,8 @@
 from __future__ import annotations
 
 import os
-import pathlib
 import platform
 import sys
-from datetime import datetime
 
 import astroid
 import platformdirs
@@ -49,9 +47,6 @@
 # on all project using [MAIN] in their rcfile.
 MAIN_CHECKER_NAME = "main"
 
-USER_HOME = os.path.expanduser("~")
-# TODO: 3.0: Remove in 3.0 with all the surrounding code
-OLD_DEFAULT_PYLINT_HOME = ".pylint.d"
 DEFAULT_PYLINT_HOME = platformdirs.user_cache_dir("pylint")
 
 DEFAULT_IGNORE_LIST = ("CVS",)
@@ -101,55 +96,10 @@ class WarningScope:
 )
 
 
-def _warn_about_old_home(pylint_home: pathlib.Path) -> None:
-    """Warn users about the old pylint home being deprecated.
-
-    The spam prevention mechanism is due to pylint being used in parallel by
-    pre-commit, and the message being spammy in this context
-    Also if you work with an old version of pylint that recreates the
-    old pylint home, you can get the old message for a long time.
-    """
-    prefix_spam_prevention = "pylint_warned_about_old_cache_already"
-    spam_prevention_file = pathlib.Path(pylint_home) / datetime.now().strftime(
-        prefix_spam_prevention + "_%Y-%m-%d.temp"
-    )
-    old_home = pathlib.Path(USER_HOME) / OLD_DEFAULT_PYLINT_HOME
-
-    if old_home.exists() and not spam_prevention_file.exists():
-        print(
-            f"PYLINTHOME is now '{pylint_home}' but obsolescent '{old_home}' is found; "
-            "you can safely remove the latter",
-            file=sys.stderr,
-        )
-
-        # Remove old spam prevention file
-        if pylint_home.exists():
-            for filename in pylint_home.iterdir():
-                if prefix_spam_prevention in str(filename):
-                    try:
-                        os.remove(pylint_home / filename)
-                    except OSError:  # pragma: no cover
-                        pass
-
-        # Create spam prevention file for today
-        try:
-            pylint_home.mkdir(parents=True, exist_ok=True)
-            with open(spam_prevention_file, "w", encoding="utf8") as f:
-                f.write("")
-        except Exception as exc:  # pragma: no cover  # pylint: disable=broad-except
-            print(
-                "Can't write the file that was supposed to "
-                f"prevent 'pylint.d' deprecation spam in {pylint_home} because of {exc}."
-            )
-
-
 def _get_pylint_home() -> str:
     """Return the pylint home."""
     if "PYLINTHOME" in os.environ:
         return os.environ["PYLINTHOME"]
-
-    _warn_about_old_home(pathlib.Path(DEFAULT_PYLINT_HOME))
-
     return DEFAULT_PYLINT_HOME
 
 

tests/lint/unittest_lint.py

@@ -7,7 +7,6 @@
 from __future__ import annotations
 
 import argparse
-import datetime
 import os
 import re
 import sys
@@ -19,6 +18,7 @@
 from os.path import abspath, dirname, join, sep
 from pathlib import Path
 from shutil import copy, rmtree
+from unittest import mock
 
 import platformdirs
 import pytest
@@ -31,11 +31,8 @@
     MSG_STATE_CONFIDENCE,
     MSG_STATE_SCOPE_CONFIG,
     MSG_STATE_SCOPE_MODULE,
-    OLD_DEFAULT_PYLINT_HOME,
     PYLINT_HOME,
-    USER_HOME,
     _get_pylint_home,
-    _warn_about_old_home,
 )
 from pylint.exceptions import InvalidMessageError
 from pylint.lint import PyLinter, expand_modules
@@ -930,58 +927,14 @@ def pop_pylintrc() -> None:
 
 @pytest.mark.usefixtures("pop_pylintrc")
 def test_pylint_home() -> None:
-    uhome = os.path.expanduser("~")
-    if uhome == "~":
-        expected = OLD_DEFAULT_PYLINT_HOME
-    else:
-        expected = platformdirs.user_cache_dir("pylint")
+    expected = platformdirs.user_cache_dir("pylint")
     assert constants.PYLINT_HOME == expected
     assert PYLINT_HOME == expected
 
 
+@mock.patch.dict(os.environ, {"PYLINTHOME": "whatever.d"})
 def test_pylint_home_from_environ() -> None:
-    try:
-        pylintd = join(tempfile.gettempdir(), OLD_DEFAULT_PYLINT_HOME)
-        os.environ["PYLINTHOME"] = pylintd
-        try:
-            assert _get_pylint_home() == pylintd
-        finally:
-            try:
-                rmtree(pylintd)
-            except FileNotFoundError:
-                pass
-    finally:
-        del os.environ["PYLINTHOME"]
-
-
-def test_warn_about_old_home(capsys: CaptureFixture[str]) -> None:
-    """Test that we correctly warn about old_home."""
-    # Create old home
-    old_home = Path(USER_HOME) / OLD_DEFAULT_PYLINT_HOME
-    old_home.mkdir(parents=True, exist_ok=True)
-
-    # Create spam prevention file
-    ten_years_ago = datetime.datetime.now() - datetime.timedelta(weeks=520)
-    new_prevention_file = Path(PYLINT_HOME) / ten_years_ago.strftime(
-        "pylint_warned_about_old_cache_already_%Y-%m-%d.temp"
-    )
-    with open(new_prevention_file, "w", encoding="utf8") as f:
-        f.write("")
-
-    # Remove current prevention file
-    cur_prevention_file = Path(PYLINT_HOME) / datetime.datetime.now().strftime(
-        "pylint_warned_about_old_cache_already_%Y-%m-%d.temp"
-    )
-    if cur_prevention_file.exists():
-        os.remove(cur_prevention_file)
-
-    _warn_about_old_home(Path(PYLINT_HOME))
-
-    assert not new_prevention_file.exists()
-    assert cur_prevention_file.exists()
-
-    out = capsys.readouterr()
-    assert "PYLINTHOME is now" in out.err
+    assert _get_pylint_home() == "whatever.d"
 
 
 class _CustomPyLinter(PyLinter):