[suggestion-mode] Remove the option and always suggest

_is_c_extension already checks if owner is a Module

See #9962 (comment)

Caching start to make sense in _similar_name

See #9962 (comment)

We had to create a clean_lru_cache file to prevent a circular import.

Author: Pierre-Sassoulas

doc/user_guide/configuration/all-options.rst

@@ -209,13 +209,6 @@ Standard Checkers
 **Default:**  ``()``
 
 
---suggestion-mode
-"""""""""""""""""
-*When enabled, pylint would attempt to guess common misconfiguration and emit user-friendly hints instead of false-positive error messages.*
-
-**Default:**  ``True``
-
-
 --unsafe-load-any-extension
 """""""""""""""""""""""""""
 *Allow loading of arbitrary C extensions. Extensions are imported into the active Python interpreter and may run arbitrary code.*
@@ -290,8 +283,6 @@ Standard Checkers
 
    source-roots = []
 
-   suggestion-mode = true
-
    unsafe-load-any-extension = false
 
 

doc/whatsnew/fragments/9962.breaking

@@ -0,0 +1,4 @@
+The ``suggestion-mode`` option was removed, as pylint now always emits user-friendly hints instead
+of false-positive error messages. You should remove it from your conf if it's defined.
+
+Refs #9962

examples/pylintrc

@@ -104,10 +104,6 @@ recursive=no
 # source root.
 source-roots=
 
-# When enabled, pylint would attempt to guess common misconfiguration and emit
-# user-friendly hints instead of false-positive error messages.
-suggestion-mode=yes
-
 # Allow loading of arbitrary C extensions. Extensions are imported into the
 # active Python interpreter and may run arbitrary code.
 unsafe-load-any-extension=no

examples/pyproject.toml

@@ -94,10 +94,6 @@ py-version = "3.12"
 # source root.
 # source-roots =
 
-# When enabled, pylint would attempt to guess common misconfiguration and emit
-# user-friendly hints instead of false-positive error messages.
-suggestion-mode = true
-
 # Allow loading of arbitrary C extensions. Extensions are imported into the
 # active Python interpreter and may run arbitrary code.
 # unsafe-load-any-extension =

pylint/checkers/clear_lru_cache.py

@@ -0,0 +1,37 @@
+# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+# For details: https://github.com/pylint-dev/pylint/blob/main/LICENSE
+# Copyright (c) https://github.com/pylint-dev/pylint/blob/main/CONTRIBUTORS.txt
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any
+
+from pylint.checkers.typecheck import _similar_names
+from pylint.checkers.utils import (
+    class_is_abstract,
+    in_for_else_branch,
+    infer_all,
+    is_overload_stub,
+    overridden_method,
+    safe_infer,
+    unimplemented_abstract_methods,
+)
+
+if TYPE_CHECKING:
+    from functools import _lru_cache_wrapper
+
+
+def clear_lru_caches() -> None:
+    """Clear caches holding references to AST nodes."""
+    caches_holding_node_references: list[_lru_cache_wrapper[Any]] = [
+        class_is_abstract,
+        in_for_else_branch,
+        infer_all,
+        is_overload_stub,
+        overridden_method,
+        unimplemented_abstract_methods,
+        safe_infer,
+        _similar_names,
+    ]
+    for lru in caches_holding_node_references:
+        lru.cache_clear()

pylint/checkers/typecheck.py

@@ -13,7 +13,7 @@
 import shlex
 import sys
 from collections.abc import Callable, Iterable
-from functools import cached_property, singledispatch
+from functools import cached_property, lru_cache, singledispatch
 from re import Pattern
 from typing import TYPE_CHECKING, Any, Literal, Union
 
@@ -172,6 +172,7 @@ def _string_distance(seq1: str, seq2: str, seq1_length: int, seq2_length: int) -
     return row[seq2_length - 1]
 
 
+@lru_cache(maxsize=256)
 def _similar_names(
     owner: SuccessfulInferenceResult,
     attrname: str | None,
@@ -214,26 +215,6 @@ def _similar_names(
     return sorted(picked)
 
 
-def _missing_member_hint(
-    owner: SuccessfulInferenceResult,
-    attrname: str | None,
-    distance_threshold: int,
-    max_choices: int,
-) -> str:
-    names = _similar_names(owner, attrname, distance_threshold, max_choices)
-    if not names:
-        # No similar name.
-        return ""
-
-    names = [repr(name) for name in names]
-    if len(names) == 1:
-        names_hint = ", ".join(names)
-    else:
-        names_hint = f"one of {', '.join(names[:-1])} or {names[-1]}"
-
-    return f"; maybe {names_hint}?"
-
-
 MSGS: dict[str, MessageDefinitionTuple] = {
     "E1101": (
         "%s %r has no %r member%s",
@@ -997,10 +978,6 @@ def open(self) -> None:
         self._py310_plus = py_version >= (3, 10)
         self._mixin_class_rgx = self.linter.config.mixin_class_rgx
 
-    @cached_property
-    def _suggestion_mode(self) -> bool:
-        return self.linter.config.suggestion_mode  # type: ignore[no-any-return]
-
     @cached_property
     def _compiled_generated_members(self) -> tuple[Pattern[str], ...]:
         # do this lazily since config not fully initialized in __init__
@@ -1211,24 +1188,24 @@ def _get_nomember_msgid_hint(
         node: nodes.Attribute | nodes.AssignAttr | nodes.DelAttr,
         owner: SuccessfulInferenceResult,
     ) -> tuple[Literal["c-extension-no-member", "no-member"], str]:
-        suggestions_are_possible = self._suggestion_mode and isinstance(
-            owner, nodes.Module
+        if _is_c_extension(owner):
+            return "c-extension-no-member", ""
+        if not self.linter.config.missing_member_hint:
+            return "no-member", ""
+        names = _similar_names(
+            owner,
+            node.attrname,
+            self.linter.config.missing_member_hint_distance,
+            self.linter.config.missing_member_max_choices,
         )
-        if suggestions_are_possible and _is_c_extension(owner):
-            msg = "c-extension-no-member"
-            hint = ""
+        if not names:
+            return "no-member", ""
+        names = [repr(name) for name in names]
+        if len(names) == 1:
+            names_hint = names[0]
         else:
-            msg = "no-member"
-            if self.linter.config.missing_member_hint:
-                hint = _missing_member_hint(
-                    owner,
-                    node.attrname,
-                    self.linter.config.missing_member_hint_distance,
-                    self.linter.config.missing_member_max_choices,
-                )
-            else:
-                hint = ""
-        return msg, hint  # type: ignore[return-value]
+            names_hint = f"one of {', '.join(names[:-1])} or {names[-1]}"
+        return "no-member", f"; maybe {names_hint}?"
 
     @only_required_for_messages(
         "assignment-from-no-return",

pylint/checkers/utils.py

@@ -16,7 +16,7 @@
 from collections.abc import Callable, Iterable, Iterator
 from functools import lru_cache, partial
 from re import Match
-from typing import TYPE_CHECKING, Any, TypeVar
+from typing import TYPE_CHECKING, TypeVar
 
 import astroid.objects
 from astroid import TooManyLevelsError, nodes, util
@@ -28,7 +28,6 @@
 from pylint.constants import TYPING_NEVER, TYPING_NORETURN
 
 if TYPE_CHECKING:
-    from functools import _lru_cache_wrapper
 
     from pylint.checkers import BaseChecker
 
@@ -2327,21 +2326,6 @@ def overridden_method(
     return None  # pragma: no cover
 
 
-def clear_lru_caches() -> None:
-    """Clear caches holding references to AST nodes."""
-    caches_holding_node_references: list[_lru_cache_wrapper[Any]] = [
-        class_is_abstract,
-        in_for_else_branch,
-        infer_all,
-        is_overload_stub,
-        overridden_method,
-        unimplemented_abstract_methods,
-        safe_infer,
-    ]
-    for lru in caches_holding_node_references:
-        lru.cache_clear()
-
-
 def is_enum_member(node: nodes.AssignName) -> bool:
     """Return `True` if `node` is an Enum member (is an item of the
     `__members__` container).

pylint/lint/base_options.py

@@ -306,19 +306,6 @@ def _make_linter_options(linter: PyLinter) -> Options:
                 ),
             },
         ),
-        (
-            "suggestion-mode",
-            {
-                "type": "yn",
-                "metavar": "<y or n>",
-                "default": True,
-                "help": (
-                    "When enabled, pylint would attempt to guess common "
-                    "misconfiguration and emit user-friendly hints instead "
-                    "of false-positive error messages."
-                ),
-            },
-        ),
         (
             "exit-zero",
             {

pylint/lint/run.py

@@ -12,7 +12,7 @@
 from typing import ClassVar
 
 from pylint import config
-from pylint.checkers.utils import clear_lru_caches
+from pylint.checkers.clear_lru_cache import clear_lru_caches
 from pylint.config._pylint_config import (
     _handle_pylint_config_commands,
     _register_generate_config_options,

pylint/utils/utils.py

@@ -40,7 +40,6 @@
 
 # These are types used to overload get_global_option() and refer to the options type
 GLOBAL_OPTION_BOOL = Literal[
-    "suggestion-mode",
     "analyse-fallback-blocks",
     "allow-global-unused-variables",
     "prefer-stubs",

pylintrc

@@ -40,10 +40,6 @@ load-plugins=
 # number of processors available to use.
 jobs=1
 
-# When enabled, pylint would attempt to guess common misconfiguration and emit
-# user-friendly hints instead of false-positive error messages.
-suggestion-mode=yes
-
 # Allow loading of arbitrary C extensions. Extensions are imported into the
 # active Python interpreter and may run arbitrary code.
 unsafe-load-any-extension=no

tests/checkers/unittest_typecheck.py

@@ -7,7 +7,7 @@
 
 from pylint.checkers import typecheck
 from pylint.interfaces import INFERENCE, UNDEFINED
-from pylint.testutils import CheckerTestCase, MessageTest, set_config
+from pylint.testutils import CheckerTestCase, MessageTest
 
 try:
     from coverage import tracer as _
@@ -27,29 +27,6 @@ class TestTypeChecker(CheckerTestCase):
 
     CHECKER_CLASS = typecheck.TypeChecker
 
-    @set_config(suggestion_mode=False)
-    @needs_c_extension
-    def test_nomember_on_c_extension_error_msg(self) -> None:
-        node = astroid.extract_node(
-            """
-        from coverage import tracer
-        tracer.CTracer  #@
-        """
-        )
-        message = MessageTest(
-            "no-member",
-            node=node,
-            args=("Module", "coverage.tracer", "CTracer", ""),
-            confidence=INFERENCE,
-            line=3,
-            col_offset=0,
-            end_line=3,
-            end_col_offset=14,
-        )
-        with self.assertAddsMessages(message):
-            self.checker.visit_attribute(node)
-
-    @set_config(suggestion_mode=True)
     @needs_c_extension
     def test_nomember_on_c_extension_info_msg(self) -> None:
         node = astroid.extract_node(