[pylint] Fix false positives, add missing methods, and support positional-only parameters (PLE0302)

crates/ruff_linter/resources/test/fixtures/pylint/unexpected_special_method_signature.py

@@ -68,8 +68,44 @@ def __round__(self, x, y, *args):  # disallow 2 args
     def __eq__(self, **kwargs):  # ignore **kwargs
         ...
 
-    def __eq__(self, /, other=42):  # ignore positional-only args
+    def __eq__(self, /, other=42):  # support positional-only args
         ...
 
-    def __eq__(self, *, other=42):  # ignore positional-only args
+    def __eq__(self, *, other=42):  # support positional-only args
         ...
+
+    def __cmp__(self): # #16217 assert non-special method is skipped, expects 2 parameters
+        ...
+
+    def __div__(self): # #16217 assert non-special method is skipped, expects 2 parameters
+        ...
+
+    def __nonzero__(self, x): # #16217 assert non-special method is skipped, expects 1 parameter
+        ...
+
+    def __unicode__(self, x): # #16217 assert non-special method is skipped, expects 1 parameter
+        ...
+
+    def __next__(self, x): # #16217 assert special method is linted, expects 1 parameter
+        ...
+
+    def __buffer__(self): # #16217 assert special method is linted, expects 2 parameters
+        ...
+
+    def __class_getitem__(self): # #16217 assert special method is linted, expects 2 parameters
+        ...
+
+    def __mro_entries__(self): # #16217 assert special method is linted, expects 2 parameters
+        ...
+
+    def __release_buffer__(self): # #16217 assert special method is linted, expects 2 parameters
+        ...
+
+    def __subclasshook__(self): # #16217 assert special method is linted, expects 2 parameters
+        ...
+
+    def __setattr__(self, /, name): # #16217 assert positional-only special method is linted, expects 3 parameters
+        ...
+
+    def __setitem__(self, key, /, value, extra_value): # #16217 assert positional-only special method is linted, expects 3 parameters
+        ...

crates/ruff_linter/src/rules/pylint/rules/unexpected_special_method_signature.rs

@@ -23,10 +23,8 @@ impl ExpectedParams {
             | "__neg__" | "__pos__" | "__abs__" | "__invert__" | "__complex__" | "__int__"
             | "__float__" | "__index__" | "__trunc__" | "__floor__" | "__ceil__" | "__enter__"
             | "__aenter__" | "__getnewargs_ex__" | "__getnewargs__" | "__getstate__"
-            | "__reduce__" | "__copy__" | "__unicode__" | "__nonzero__" | "__await__"
-            | "__aiter__" | "__anext__" | "__fspath__" | "__subclasses__" => {
-                Some(ExpectedParams::Fixed(0))
-            }
+            | "__reduce__" | "__copy__" | "__await__" | "__aiter__" | "__anext__"
+            | "__fspath__" | "__subclasses__" | "__next__" => Some(ExpectedParams::Fixed(0)),
             "__format__" | "__lt__" | "__le__" | "__eq__" | "__ne__" | "__gt__" | "__ge__"
             | "__getattr__" | "__getattribute__" | "__delattr__" | "__delete__"
             | "__instancecheck__" | "__subclasscheck__" | "__getitem__" | "__missing__"
@@ -37,8 +35,9 @@ impl ExpectedParams {
             | "__rpow__" | "__rlshift__" | "__rrshift__" | "__rand__" | "__rxor__" | "__ror__"
             | "__iadd__" | "__isub__" | "__imul__" | "__itruediv__" | "__ifloordiv__"
             | "__imod__" | "__ilshift__" | "__irshift__" | "__iand__" | "__ixor__" | "__ior__"
-            | "__ipow__" | "__setstate__" | "__reduce_ex__" | "__deepcopy__" | "__cmp__"
-            | "__matmul__" | "__rmatmul__" | "__imatmul__" | "__div__" => {
+            | "__ipow__" | "__setstate__" | "__reduce_ex__" | "__deepcopy__" | "__matmul__"
+            | "__rmatmul__" | "__imatmul__" | "__buffer__" | "__class_getitem__"
+            | "__mro_entries__" | "__release_buffer__" | "__subclasshook__" => {
                 Some(ExpectedParams::Fixed(1))
             }
             "__setattr__" | "__get__" | "__set__" | "__setitem__" | "__set_name__" => {
@@ -147,11 +146,8 @@ pub(crate) fn unexpected_special_method_signature(
         return;
     }
 
-    // Ignore methods with positional-only or keyword-only parameters, or variadic parameters.
-    if !parameters.posonlyargs.is_empty()
-        || !parameters.kwonlyargs.is_empty()
-        || parameters.kwarg.is_some()
-    {
+    // Ignore methods with keyword-only parameters or variadic parameters.
+    if !parameters.kwonlyargs.is_empty() || parameters.kwarg.is_some() {
         return;
     }
 
@@ -160,10 +156,11 @@ pub(crate) fn unexpected_special_method_signature(
         return;
     }
 
-    let actual_params = parameters.args.len();
+    let actual_params = parameters.args.len() + parameters.posonlyargs.len();
     let mandatory_params = parameters
         .args
         .iter()
+        .chain(parameters.posonlyargs.iter())
         .filter(|arg| arg.default.is_none())
         .count();
 

crates/ruff_linter/src/rules/pylint/snapshots/ruff_linter__rules__pylint__tests__PLE0302_unexpected_special_method_signature.py.snap

@@ -71,3 +71,75 @@ unexpected_special_method_signature.py:65:9: PLE0302 The special method `__round
    |         ^^^^^^^^^ PLE0302
 66 |         ...
    |
+
+unexpected_special_method_signature.py:89:9: PLE0302 The special method `__next__` expects 1 parameter, 2 were given
+   |
+87 |         ...
+88 |
+89 |     def __next__(self, x): # #16217 assert special method is linted, expects 1 parameter
+   |         ^^^^^^^^ PLE0302
+90 |         ...
+   |
+
+unexpected_special_method_signature.py:92:9: PLE0302 The special method `__buffer__` expects 2 parameters, 1 was given
+   |
+90 |         ...
+91 |
+92 |     def __buffer__(self): # #16217 assert special method is linted, expects 2 parameters
+   |         ^^^^^^^^^^ PLE0302
+93 |         ...
+   |
+
+unexpected_special_method_signature.py:95:9: PLE0302 The special method `__class_getitem__` expects 2 parameters, 1 was given
+   |
+93 |         ...
+94 |
+95 |     def __class_getitem__(self): # #16217 assert special method is linted, expects 2 parameters
+   |         ^^^^^^^^^^^^^^^^^ PLE0302
+96 |         ...
+   |
+
+unexpected_special_method_signature.py:98:9: PLE0302 The special method `__mro_entries__` expects 2 parameters, 1 was given
+   |
+96 |         ...
+97 |
+98 |     def __mro_entries__(self): # #16217 assert special method is linted, expects 2 parameters
+   |         ^^^^^^^^^^^^^^^ PLE0302
+99 |         ...
+   |
+
+unexpected_special_method_signature.py:101:9: PLE0302 The special method `__release_buffer__` expects 2 parameters, 1 was given
+    |
+ 99 |         ...
+100 |
+101 |     def __release_buffer__(self): # #16217 assert special method is linted, expects 2 parameters
+    |         ^^^^^^^^^^^^^^^^^^ PLE0302
+102 |         ...
+    |
+
+unexpected_special_method_signature.py:104:9: PLE0302 The special method `__subclasshook__` expects 2 parameters, 1 was given
+    |
+102 |         ...
+103 |
+104 |     def __subclasshook__(self): # #16217 assert special method is linted, expects 2 parameters
+    |         ^^^^^^^^^^^^^^^^ PLE0302
+105 |         ...
+    |
+
+unexpected_special_method_signature.py:107:9: PLE0302 The special method `__setattr__` expects 3 parameters, 2 were given
+    |
+105 |         ...
+106 |
+107 |     def __setattr__(self, /, name): # #16217 assert positional-only special method is linted, expects 3 parameters
+    |         ^^^^^^^^^^^ PLE0302
+108 |         ...
+    |
+
+unexpected_special_method_signature.py:110:9: PLE0302 The special method `__setitem__` expects 3 parameters, 4 were given
+    |
+108 |         ...
+109 |
+110 |     def __setitem__(self, key, /, value, extra_value): # #16217 assert positional-only special method is linted, expects 3 parameters
+    |         ^^^^^^^^^^^ PLE0302
+111 |         ...
+    |