[`flake8-self`] Fix False Negative Issue on Rule `SLF001` (#2527)

resources/test/fixtures/flake8_self/SLF001.py

@@ -1,13 +1,40 @@
-class Foo:
+class BazMeta(type):
+    _private_count = 1
+
+    def __new__(mcs, name, bases, attrs):
+        if mcs._private_count <= 5:
+            mcs.some_method()
+
+        return super().__new__(mcs, name, bases, attrs)
+
+    def some_method():
+        pass
+
+
+class Bar:
+    _private = True
+
+    @classmethod
+    def is_private(cls):
+        return cls._private
+
+
+class Foo(metaclass=BazMeta):
 
     def __init__(self):
         self.public_thing = "foo"
         self._private_thing = "bar"
         self.__really_private_thing = "baz"
+        self.bar = Bar()
 
     def __str__(self):
         return "foo"
 
+    def get_bar():
+        if self.bar._private:  # SLF001
+            return None
+        return self.bar
+
     def public_func(self):
         pass
 
@@ -29,3 +56,4 @@ print(foo._private_thing)  # SLF001
 print(foo.__really_private_thing)  # SLF001
 print(foo._private_func())  # SLF001
 print(foo.__really_private_func(1))  # SLF001
+print(foo.bar._private)  # SLF001

src/rules/flake8_self/rules/private_member_access.rs

@@ -26,8 +26,10 @@ const VALID_IDS: [&str; 3] = ["self", "cls", "mcs"];
 pub fn private_member_access(checker: &mut Checker, expr: &Expr) {
     if let ExprKind::Attribute { value, attr, .. } = &expr.node {
         if !attr.ends_with("__") && (attr.starts_with('_') || attr.starts_with("__")) {
-            let ExprKind::Name { id, .. } = &value.node else {
-                return;
+            let id = match &value.node {
+                ExprKind::Name { id, .. } => id,
+                ExprKind::Attribute { attr, .. } => attr,
+                _ => return,
             };
 
             if !VALID_IDS.contains(&id.as_str()) {

src/rules/flake8_self/snapshots/ruff__rules__flake8_self__tests__private-member-access_SLF001.py.snap

@@ -2,14 +2,25 @@
 source: src/rules/flake8_self/mod.rs
 expression: diagnostics
 ---
+- kind:
+    PrivateMemberAccess:
+      access: bar._private
+  location:
+    row: 34
+    column: 11
+  end_location:
+    row: 34
+    column: 28
+  fix: ~
+  parent: ~
 - kind:
     PrivateMemberAccess:
       access: foo._private_thing
   location:
-    row: 28
+    row: 55
     column: 6
   end_location:
-    row: 28
+    row: 55
     column: 24
   fix: ~
   parent: ~
@@ -17,10 +28,10 @@ expression: diagnostics
     PrivateMemberAccess:
       access: foo.__really_private_thing
   location:
-    row: 29
+    row: 56
     column: 6
   end_location:
-    row: 29
+    row: 56
     column: 32
   fix: ~
   parent: ~
@@ -28,10 +39,10 @@ expression: diagnostics
     PrivateMemberAccess:
       access: foo._private_func
   location:
-    row: 30
+    row: 57
     column: 6
   end_location:
-    row: 30
+    row: 57
     column: 23
   fix: ~
   parent: ~
@@ -39,11 +50,22 @@ expression: diagnostics
     PrivateMemberAccess:
       access: foo.__really_private_func
   location:
-    row: 31
+    row: 58
     column: 6
   end_location:
-    row: 31
+    row: 58
     column: 31
   fix: ~
   parent: ~
+- kind:
+    PrivateMemberAccess:
+      access: bar._private
+  location:
+    row: 59
+    column: 6
+  end_location:
+    row: 59
+    column: 22
+  fix: ~
+  parent: ~