Prevent useless-suppression on disables for stdlib deprecation checker (#5876)

Co-authored-by: Marc Mueller <[email protected]>

Author: jacobtylerwalls

ChangeLog

@@ -421,6 +421,10 @@ Release date: TBA
 
   Closes #5862
 
+* Disables for ``deprecated-module`` and similar warnings for stdlib features deprecated
+  in newer versions of Python no longer raise ``useless-suppression`` when linting with
+  older Python interpreters where those features are not yet deprecated.
+
 * Importing the deprecated stdlib module ``distutils`` now emits ``deprecated_module`` on Python 3.10+.
 
 * ``missing-raises-doc`` will now check the class hierarchy of the raised exceptions

doc/whatsnew/2.13.rst

@@ -402,6 +402,10 @@ Other Changes
 * The ``testutils`` for unittests now accept ``end_lineno`` and ``end_column``. Tests
   without these will trigger a ``DeprecationWarning``.
 
+* Disables for ``deprecated-module`` and similar warnings for stdlib features deprecated
+  in newer versions of Python no longer raise ``useless-suppression`` when linting with
+  older Python interpreters where those features are not yet deprecated.
+
 * Importing the deprecated stdlib module ``xml.etree.cElementTree`` now emits ``deprecated_module``.
 
   Closes #5862

pylint/checkers/stdlib.py

@@ -39,7 +39,7 @@
 
 import sys
 from collections.abc import Iterable
-from typing import TYPE_CHECKING, Any, Dict, List, Optional, Set
+from typing import TYPE_CHECKING, Dict, List, Optional, Set, Tuple
 
 import astroid
 from astroid import nodes
@@ -473,24 +473,26 @@ class StdlibChecker(DeprecatedMixin, BaseChecker):
 
     def __init__(self, linter: Optional["PyLinter"] = None) -> None:
         BaseChecker.__init__(self, linter)
-        self._deprecated_methods: Set[Any] = set()
-        self._deprecated_methods.update(DEPRECATED_METHODS[0])
+        self._deprecated_methods: Set[str] = set()
+        self._deprecated_arguments: Dict[
+            str, Tuple[Tuple[Optional[int], str], ...]
+        ] = {}
+        self._deprecated_classes: Dict[str, Set[str]] = {}
+        self._deprecated_modules: Set[str] = set()
+        self._deprecated_decorators: Set[str] = set()
+
         for since_vers, func_list in DEPRECATED_METHODS[sys.version_info[0]].items():
             if since_vers <= sys.version_info:
                 self._deprecated_methods.update(func_list)
-        self._deprecated_attributes = {}
         for since_vers, func_list in DEPRECATED_ARGUMENTS.items():
             if since_vers <= sys.version_info:
-                self._deprecated_attributes.update(func_list)
-        self._deprecated_classes = {}
+                self._deprecated_arguments.update(func_list)
         for since_vers, class_list in DEPRECATED_CLASSES.items():
             if since_vers <= sys.version_info:
                 self._deprecated_classes.update(class_list)
-        self._deprecated_modules = set()
         for since_vers, mod_list in DEPRECATED_MODULES.items():
             if since_vers <= sys.version_info:
                 self._deprecated_modules.update(mod_list)
-        self._deprecated_decorators = set()
         for since_vers, decorator_list in DEPRECATED_DECORATORS.items():
             if since_vers <= sys.version_info:
                 self._deprecated_decorators.update(decorator_list)
@@ -788,7 +790,7 @@ def deprecated_methods(self):
         return self._deprecated_methods
 
     def deprecated_arguments(self, method: str):
-        return self._deprecated_attributes.get(method, ())
+        return self._deprecated_arguments.get(method, ())
 
     def deprecated_classes(self, module: str):
         return self._deprecated_classes.get(module, ())

pylint/constants.py

@@ -173,3 +173,20 @@ class DeletedMessage(NamedTuple):
     # https://github.com/PyCQA/pylint/pull/3571
     DeletedMessage("C0330", "bad-continuation"),
 ]
+
+
+# ignore some messages when emitting useless-suppression:
+# - cyclic-import: can show false positives due to incomplete context
+# - deprecated-{module, argument, class, method, decorator}:
+#   can cause false positives for multi-interpreter projects
+#   when linting with an interpreter on a lower python version
+INCOMPATIBLE_WITH_USELESS_SUPPRESSION = frozenset(
+    [
+        "R0401",  # cyclic-import
+        "W0402",  # deprecated-module
+        "W1505",  # deprecated-method
+        "W1511",  # deprecated-argument
+        "W1512",  # deprecated-class
+        "W1513",  # deprecated-decorator
+    ]
+)

pylint/utils/file_state.py

@@ -16,7 +16,11 @@
 
 from astroid import nodes
 
-from pylint.constants import MSG_STATE_SCOPE_MODULE, WarningScope
+from pylint.constants import (
+    INCOMPATIBLE_WITH_USELESS_SUPPRESSION,
+    MSG_STATE_SCOPE_MODULE,
+    WarningScope,
+)
 
 if sys.version_info >= (3, 8):
     from typing import Literal
@@ -159,13 +163,14 @@ def iter_spurious_suppression_messages(
     ]:
         for warning, lines in self._raw_module_msgs_state.items():
             for line, enable in lines.items():
-                if not enable and (warning, line) not in self._ignored_msgs:
-                    # ignore cyclic-import check which can show false positives
-                    # here due to incomplete context
-                    if warning != "R0401":
-                        yield "useless-suppression", line, (
-                            msgs_store.get_msg_display_string(warning),
-                        )
+                if (
+                    not enable
+                    and (warning, line) not in self._ignored_msgs
+                    and warning not in INCOMPATIBLE_WITH_USELESS_SUPPRESSION
+                ):
+                    yield "useless-suppression", line, (
+                        msgs_store.get_msg_display_string(warning),
+                    )
         # don't use iteritems here, _ignored_msgs may be modified by add_message
         for (warning, from_), ignored_lines in list(self._ignored_msgs.items()):
             for line in ignored_lines:

tests/functional/d/deprecated/deprecated_method_suppression.py

@@ -0,0 +1,8 @@
+"""Test that versions below Py3.10 will not emit useless-suppression for
+disabling deprecated-method (on a method deprecated in Py3.10.
+
+This test can be run on all Python versions, but it will lack value when
+Pylint drops support for 3.9."""
+# pylint: disable=import-error, unused-import
+
+import threading.current_thread  # pylint: disable=deprecated-method

tests/functional/d/deprecated/deprecated_methods_py39.py

@@ -0,0 +1,4 @@
+"""Test deprecated methods from Python 3.9."""
+
+import binascii
+binascii.b2a_hqx() # [deprecated-method]

tests/functional/d/deprecated/deprecated_methods_py39.rc

@@ -0,0 +1,2 @@
+[testoptions]
+min_pyver=3.9

tests/functional/d/deprecated/deprecated_methods_py39.txt

@@ -0,0 +1 @@
+deprecated-method:4:0:4:18::Using deprecated method b2a_hqx():UNDEFINED

tests/functional/d/deprecated/deprecated_module_py3.txt

@@ -1 +1 @@
-deprecated-module:4:::Uses of a deprecated module 'optparse'
+deprecated-module:4:0:4:15::Uses of a deprecated module 'optparse':UNDEFINED

tests/functional/d/deprecated/deprecated_module_py39.py

@@ -0,0 +1,4 @@
+"""Test deprecated modules from Python 3.9."""
+# pylint: disable=unused-import
+
+import binhex  # [deprecated-module]

tests/functional/d/deprecated/deprecated_module_py39.rc

@@ -0,0 +1,2 @@
+[testoptions]
+min_pyver=3.9

tests/functional/d/deprecated/deprecated_module_py39.txt

@@ -0,0 +1 @@
+deprecated-module:4:0:4:13::Uses of a deprecated module 'binhex':UNDEFINED

tests/functional/d/deprecated/deprecated_module_py39_earlier_pyversion.py

@@ -0,0 +1,6 @@
+"""Test deprecated modules from Python 3.9,
+but use an earlier --py-version and ensure a warning is still emitted.
+"""
+# pylint: disable=unused-import
+
+import binhex  # [deprecated-module]

tests/functional/d/deprecated/deprecated_module_py39_earlier_pyversion.rc

@@ -0,0 +1,5 @@
+[master]
+py-version=3.8
+
+[testoptions]
+min_pyver=3.9

tests/functional/d/deprecated/deprecated_module_py39_earlier_pyversion.txt

@@ -0,0 +1 @@
+deprecated-module:6:0:6:13::Uses of a deprecated module 'binhex':UNDEFINED