Add ``mixin-class-rgx`` option (#5203)

Co-authored-by: Alpha <alpha@pokesplash.net>

Co-authored-by: Pierre Sassoulas <pierre.sassoulas@gmail.com>

12 files changed, 118 insertions, 15 deletions

diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index 545691405..881d53db6 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -390,6 +390,8 @@ contributors:
 
 * Ram Rachum (cool-RR)
 
+* D. Alphus (Alphadelta14): contributor
+
 * Pieter Engelbrecht
 
 * Ethan Leba: contributor
diff --git a/ChangeLog b/ChangeLog
index 12365068a..732a62f35 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -74,6 +74,8 @@ Release date: TBA
 
   Closes #4981
 
+* Support configuring mixin class pattern via ``mixin-class-rgx``
+
 * Added new checker ``use-implicit-booleaness-not-comparison``: Emitted when
   collection literal comparison is being used to check for emptiness.
 
diff --git a/doc/faq.rst b/doc/faq.rst
index 479d3c052..d0a02cf3a 100644
--- a/doc/faq.rst
+++ b/doc/faq.rst
@@ -238,8 +238,9 @@ methods is doing nothing but raising NotImplementedError.
 -------------------------------------------------------------------------------
 
 To do so you have to set the ignore-mixin-members option to
-"yes" (this is the default value) and to name your mixin class with
-a name which ends with "mixin" (whatever case).
+"yes" (this is the default value) and name your mixin class with
+a name which ends with "Mixin" or "mixin" (default) or change the
+default value by changing the mixin-class-rgx option.
 
 
 6. Troubleshooting
diff --git a/doc/whatsnew/2.12.rst b/doc/whatsnew/2.12.rst
index 8b5b5f0c2..af5b33a43 100644
--- a/doc/whatsnew/2.12.rst
+++ b/doc/whatsnew/2.12.rst
@@ -90,6 +90,8 @@ Other Changes
 
   Closes #4426
 
+* Support configuring mixin class pattern via ``mixin-class-rgx``
+
 * Normalize the input to the ``ignore-paths`` option to allow both Posix and
   Windows paths
 
diff --git a/pylint/checkers/async.py b/pylint/checkers/async.py
index f9d1e15dd..9aaead7c4 100644
--- a/pylint/checkers/async.py
+++ b/pylint/checkers/async.py
@@ -44,6 +44,7 @@ class AsyncChecker(checkers.BaseChecker):
         self._ignore_mixin_members = utils.get_global_option(
             self, "ignore-mixin-members"
         )
+        self._mixin_class_rgx = utils.get_global_option(self, "mixin-class-rgx")
         self._async_generators = ["contextlib.asynccontextmanager"]
 
     @checker_utils.check_messages("yield-inside-async-function")
@@ -81,10 +82,11 @@ class AsyncChecker(checkers.BaseChecker):
                         # just skip it.
                         if not checker_utils.has_known_bases(inferred):
                             continue
-                        # Just ignore mixin classes.
-                        if self._ignore_mixin_members:
-                            if inferred.name[-5:].lower() == "mixin":
-                                continue
+                        # Ignore mixin classes if they match the rgx option.
+                        if self._ignore_mixin_members and self._mixin_class_rgx.match(
+                            inferred.name
+                        ):
+                            continue
                 else:
                     continue
             self.add_message(
diff --git a/pylint/checkers/classes.py b/pylint/checkers/classes.py
index 0b15861b0..2ab66fd0b 100644
--- a/pylint/checkers/classes.py
+++ b/pylint/checkers/classes.py
@@ -808,6 +808,9 @@ a metaclass class method.",
         self._first_attrs = []
         self._meth_could_be_func = None
 
+    def open(self) -> None:
+        self._mixin_class_rgx = get_global_option(self, "mixin-class-rgx")
+
     @astroid.decorators.cachedproperty
     def _dummy_rgx(self):
         return get_global_option(self, "dummy-variables-rgx", default=None)
@@ -1029,7 +1032,7 @@ a metaclass class method.",
 
     def _check_attribute_defined_outside_init(self, cnode: nodes.ClassDef) -> None:
         # check access to existent members on non metaclass classes
-        if self._ignore_mixin and cnode.name[-5:].lower() == "mixin":
+        if self._ignore_mixin and self._mixin_class_rgx.match(cnode.name):
             # We are in a mixin class. No need to try to figure out if
             # something is missing, since it is most likely that it will
             # miss.
diff --git a/pylint/checkers/typecheck.py b/pylint/checkers/typecheck.py
index 8fa80ee21..549cd7f4c 100644
--- a/pylint/checkers/typecheck.py
+++ b/pylint/checkers/typecheck.py
@@ -442,7 +442,14 @@ SEQUENCE_TYPES = {
 }
 
 
-def _emit_no_member(node, owner, owner_name, ignored_mixins=True, ignored_none=True):
+def _emit_no_member(
+    node,
+    owner,
+    owner_name,
+    mixin_class_rgx: Pattern[str],
+    ignored_mixins=True,
+    ignored_none=True,
+):
     """Try to see if no-member should be emitted for the given owner.
 
     The following cases are ignored:
@@ -462,7 +469,7 @@ def _emit_no_member(node, owner, owner_name, ignored_mixins=True, ignored_none=T
         return False
     if is_super(owner) or getattr(owner, "type", None) == "metaclass":
         return False
-    if owner_name and ignored_mixins and owner_name[-5:].lower() == "mixin":
+    if owner_name and ignored_mixins and mixin_class_rgx.match(owner_name):
         return False
     if isinstance(owner, nodes.FunctionDef) and (
         owner.decorators or owner.is_abstract()
@@ -781,14 +788,24 @@ class TypeChecker(BaseChecker):
             },
         ),
         (
+            "mixin-class-rgx",
+            {
+                "default": ".*[Mm]ixin",
+                "type": "regexp",
+                "metavar": "<regexp>",
+                "help": "Regex pattern to define which classes are considered mixins "
+                "ignore-mixin-members is set to 'yes'",
+            },
+        ),
+        (
             "ignore-mixin-members",
             {
                 "default": True,
                 "type": "yn",
                 "metavar": "<y_or_n>",
-                "help": 'Tells whether missing members accessed in mixin \
-class should be ignored. A mixin class is detected if its name ends with \
-"mixin" (case insensitive).',
+                "help": "Tells whether missing members accessed in mixin "
+                "class should be ignored. A class is considered mixin if its name matches "
+                "the mixin-class-rgx option.",
             },
         ),
         (
@@ -898,6 +915,7 @@ accessed. Python regular expressions are accepted.",
     def open(self) -> None:
         py_version = get_global_option(self, "py-version")
         self._py310_plus = py_version >= (3, 10)
+        self._mixin_class_rgx = get_global_option(self, "mixin-class-rgx")
 
     @astroid.decorators.cachedproperty
     def _suggestion_mode(self):
@@ -1040,6 +1058,7 @@ accessed. Python regular expressions are accepted.",
                     node,
                     owner,
                     name,
+                    self._mixin_class_rgx,
                     ignored_mixins=self.config.ignore_mixin_members,
                     ignored_none=self.config.ignore_none,
                 ):
diff --git a/pylint/utils/utils.py b/pylint/utils/utils.py
index 6c9f11298..8243bc322 100644
--- a/pylint/utils/utils.py
+++ b/pylint/utils/utils.py
@@ -54,7 +54,10 @@ GLOBAL_OPTION_BOOL = Literal[
 GLOBAL_OPTION_INT = Literal["max-line-length", "docstring-min-length"]
 GLOBAL_OPTION_LIST = Literal["ignored-modules"]
 GLOBAL_OPTION_PATTERN = Literal[
-    "no-docstring-rgx", "dummy-variables-rgx", "ignored-argument-names"
+    "no-docstring-rgx",
+    "dummy-variables-rgx",
+    "ignored-argument-names",
+    "mixin-class-rgx",
 ]
 GLOBAL_OPTION_PATTERN_LIST = Literal["ignore-paths"]
 GLOBAL_OPTION_TUPLE_INT = Literal["py-version"]
diff --git a/pylintrc b/pylintrc
index b4a4e9fac..e5cbc1220 100644
--- a/pylintrc
+++ b/pylintrc
@@ -270,10 +270,13 @@ property-classes=abc.abstractproperty
 
 [TYPECHECK]
 
-# Tells whether missing members accessed in mixin class should be ignored. A
-# mixin class is detected if its name ends with "mixin" (case insensitive).
+# Tells whether missing members accessed in mixin class should be ignored.
+# A class is considered mixin if its name matches the mixin-class-rgx option.
 ignore-mixin-members=yes
 
+# Regex pattern to define which classes are considered mixins.
+mixin-class-rgx=.*MixIn
+
 # List of module names for which member attributes should not be checked
 # (useful for modules/projects where namespaces are manipulated during runtime
 # and thus existing member attributes cannot be deduced by static analysis)
diff --git a/tests/functional/m/mixin_class_rgx.py b/tests/functional/m/mixin_class_rgx.py
new file mode 100644
index 000000000..1f6ea21e6
--- /dev/null
+++ b/tests/functional/m/mixin_class_rgx.py
@@ -0,0 +1,60 @@
+"""Tests for the mixin-class-rgx option"""
+# pylint: disable=too-few-public-methods
+
+
+# Tests for not-async-context-manager
+
+
+class AsyncManagerMixedin:
+    """Class that does not match the option pattern"""
+
+    def __aenter__(self):
+        pass
+
+
+class AsyncManagerMixin:
+    """Class that does match the option pattern"""
+
+    def __aenter__(self):
+        pass
+
+
+async def check_not_async_context_manager():
+    """Function calling the classes for not-async-context-manager"""
+    async with AsyncManagerMixedin:  # [not-async-context-manager]
+        pass
+    async with AsyncManagerMixin():
+        pass
+
+
+# Tests for attribute-defined-outside-init
+
+
+class OutsideInitMixedin:
+    """Class that does not match the option pattern"""
+
+    def set_attribute(self):
+        """Set an attribute outside of __init__"""
+        self.attr = 1  # [attribute-defined-outside-init]
+
+
+class OutsideInitMixin:
+    """Class that does match the option pattern"""
+
+    def set_attribute(self):
+        """Set an attribute outside of __init__"""
+        self.attr = 1
+
+
+# Tests for no-member
+
+
+class NoMemberMixedin:
+    """Class that does not match the option pattern"""
+
+MY_CLASS = OutsideInitMixedin().method() # [no-member]
+
+class NoMemberMixin:
+    """Class that does match the option pattern"""
+
+MY_OTHER_CLASS = NoMemberMixin().method()
diff --git a/tests/functional/m/mixin_class_rgx.rc b/tests/functional/m/mixin_class_rgx.rc
new file mode 100644
index 000000000..4ca300e4a
--- /dev/null
+++ b/tests/functional/m/mixin_class_rgx.rc
@@ -0,0 +1,3 @@
+[TYPECHECK]
+ignore-mixin-members=yes
+mixin-class-rgx=.*[Mm]ixin
diff --git a/tests/functional/m/mixin_class_rgx.txt b/tests/functional/m/mixin_class_rgx.txt
new file mode 100644
index 000000000..eb39a1185
--- /dev/null
+++ b/tests/functional/m/mixin_class_rgx.txt
@@ -0,0 +1,3 @@
+not-async-context-manager:24:4:check_not_async_context_manager:Async context manager 'AsyncManagerMixedin' doesn't implement __aenter__ and __aexit__.:HIGH
+attribute-defined-outside-init:38:8:OutsideInitMixedin.set_attribute:Attribute 'attr' defined outside __init__:HIGH
+no-member:55:11::Instance of 'OutsideInitMixedin' has no 'method' member:INFERENCE