[ty] Remove `Self` from generic context when binding `Self`

crates/ty_python_semantic/src/types/generics.rs

@@ -17,8 +17,8 @@ use crate::types::tuple::{TupleSpec, TupleType, walk_tuple_type};
 use crate::types::{
     ApplyTypeMappingVisitor, BoundTypeVarInstance, FindLegacyTypeVarsVisitor, HasRelationToVisitor,
     IsEquivalentVisitor, KnownClass, KnownInstanceType, MaterializationKind, NormalizedVisitor,
-    Type, TypeMapping, TypeRelation, TypeVarBoundOrConstraints, TypeVarInstance, TypeVarVariance,
+    Type, TypeMapping, TypeRelation, TypeVarBoundOrConstraints, TypeVarInstance, TypeVarKind,
-    UnionType, binding_type, declaration_type,
+    TypeVarVariance, UnionType, binding_type, declaration_type,
 };
 use crate::{Db, FxOrderSet};
 
@@ -401,6 +401,17 @@ impl<'db> GenericContext<'db> {
     fn heap_size((variables,): &(FxOrderSet<BoundTypeVarInstance<'db>>,)) -> usize {
         ruff_memory_usage::order_set_heap_size(variables)
     }
+
+    /// Returns a version of this generic context with the `Self` typevar removed.
+    pub(crate) fn bind_self(self, db: &'db dyn Db) -> Self {
+        Self::from_typevar_instances(
+            db,
+            self.variables(db)
+                .iter()
+                .filter(|typevar| typevar.typevar(db).kind(db) != TypeVarKind::TypingSelf)
+                .copied(),
+        )
+    }
 }
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]

crates/ty_python_semantic/src/types/signatures.rs

@@ -522,7 +522,7 @@ impl<'db> Signature<'db> {
                 return_ty.map(|ty| ty.apply_type_mapping(db, &TypeMapping::BindSelf(self_type)));
         }
         Self {
-            generic_context: self.generic_context,
+            generic_context: self.generic_context.map(|context| context.bind_self(db)),
             inherited_generic_context: self.inherited_generic_context,
             definition: self.definition,
             parameters,