Copy over binding context from old typevar

Author: sharkdp

crates/ty_python_semantic/resources/mdtest/named_tuple.md

@@ -270,7 +270,7 @@ reveal_type(Person._field_defaults)  # revealed: dict[str, Any]
 reveal_type(Person._fields)  # revealed: tuple[str, ...]
 reveal_type(Person._make)  # revealed: bound method <class 'Person'>._make(iterable: Iterable[Any]) -> Person
 reveal_type(Person._asdict)  # revealed: def _asdict(self) -> dict[str, Any]
-reveal_type(Person._replace)  # revealed: def _replace(self, **kwargs: Any) -> Self
+reveal_type(Person._replace)  # revealed: def _replace(self, **kwargs: Any) -> Self@_replace
 
 # TODO: should be `Person` once we support implicit type of `self`
 reveal_type(Person._make(("Alice", 42)))  # revealed: Unknown
@@ -373,7 +373,7 @@ class Point(NamedTuple):
 
 reveal_type(Point._make)  # revealed: bound method <class 'Point'>._make(iterable: Iterable[Any]) -> Point
 reveal_type(Point._asdict)  # revealed: def _asdict(self) -> dict[str, Any]
-reveal_type(Point._replace)  # revealed: def _replace(self, **kwargs: Any) -> Self
+reveal_type(Point._replace)  # revealed: def _replace(self, **kwargs: Any) -> Self@_replace
 
 static_assert(is_assignable_to(Point, NamedTuple))
 

crates/ty_python_semantic/src/types.rs

@@ -5973,7 +5973,13 @@ impl<'db> Type<'db> {
                 }
                 TypeMapping::ReplaceSelf { new_upper_bound } => {
                     if bound_typevar.typevar(db).is_self(db) {
-                        Type::TypeVar(BoundTypeVarInstance::synthetic_self(db, *new_upper_bound))
+                        Type::TypeVar(
+                            BoundTypeVarInstance::synthetic_self(
+                                db,
+                                *new_upper_bound,
+                                bound_typevar.binding_context(db)
+                            )
+                        )
                     } else {
                         self
                     }
@@ -7690,7 +7696,11 @@ impl<'db> BoundTypeVarInstance<'db> {
     }
 
     /// Create a new synthetic `Self` type variable with the given upper bound.
-    pub(crate) fn synthetic_self(db: &'db dyn Db, upper_bound: Type<'db>) -> Self {
+    pub(crate) fn synthetic_self(
+        db: &'db dyn Db,
+        upper_bound: Type<'db>,
+        binding_context: BindingContext<'db>,
+    ) -> Self {
         Self::new(
             db,
             TypeVarInstance::new(
@@ -7702,7 +7712,7 @@ impl<'db> BoundTypeVarInstance<'db> {
                 None,
                 TypeVarKind::TypingSelf,
             ),
-            BindingContext::Synthetic,
+            binding_context,
         )
     }
 

crates/ty_python_semantic/src/types/signatures.rs

@@ -22,7 +22,7 @@ use crate::types::generics::{GenericContext, walk_generic_context};
 use crate::types::{
     ApplyTypeMappingVisitor, BindingContext, BoundTypeVarInstance, FindLegacyTypeVarsVisitor,
     HasRelationToVisitor, IsEquivalentVisitor, KnownClass, MaterializationKind, NormalizedVisitor,
-    TypeMapping, TypeRelation, TypeVarKind, VarianceInferable, todo_type,
+    TypeMapping, TypeRelation, VarianceInferable, todo_type,
 };
 use crate::{Db, FxOrderSet};
 use ruff_python_ast::{self as ast, name::Name};
@@ -474,11 +474,15 @@ impl<'db> Signature<'db> {
                 self.generic_context.map(|context| {
                     GenericContext::from_typevar_instances(
                         db,
-                        context.variables(db).iter().map(|var| {
-                            if var.typevar(db).kind(db) == TypeVarKind::TypingSelf {
-                                BoundTypeVarInstance::synthetic_self(db, *new_upper_bound)
+                        context.variables(db).iter().map(|typevar| {
+                            if typevar.typevar(db).is_self(db) {
+                                BoundTypeVarInstance::synthetic_self(
+                                    db,
+                                    *new_upper_bound,
+                                    typevar.binding_context(db),
+                                )
                             } else {
-                                *var
+                                *typevar
                             }
                         }),
                     )