Fix ?

Author: fangyi-zhou

conformance/third_party/conformance.exp

@@ -6383,28 +6383,6 @@
     }
   ],
   "generics_self_usage.py": [
-    {
-      "code": -2,
-      "column": 16,
-      "concise_description": "Returned type `ReturnsSelf` is not assignable to declared return type `Self@ReturnsSelf`",
-      "description": "Returned type `ReturnsSelf` is not assignable to declared return type `Self@ReturnsSelf`",
-      "line": 15,
-      "name": "bad-return",
-      "severity": "error",
-      "stop_column": 22,
-      "stop_line": 15
-    },
-    {
-      "code": -2,
-      "column": 16,
-      "concise_description": "Returned type `ReturnsSelf` is not assignable to declared return type `Self@ReturnsSelf`",
-      "description": "Returned type `ReturnsSelf` is not assignable to declared return type `Self@ReturnsSelf`",
-      "line": 18,
-      "name": "bad-return",
-      "severity": "error",
-      "stop_column": 22,
-      "stop_line": 18
-    },
     {
       "code": -2,
       "column": 14,

conformance/third_party/conformance.result

@@ -117,9 +117,7 @@
   "generics_self_basic.py": [],
   "generics_self_protocols.py": [],
   "generics_self_usage.py": [
-    "Line 82: Expected 1 errors",
-    "Line 15: Unexpected errors ['Returned type `ReturnsSelf` is not assignable to declared return type `Self@ReturnsSelf`']",
-    "Line 18: Unexpected errors ['Returned type `ReturnsSelf` is not assignable to declared return type `Self@ReturnsSelf`']"
+    "Line 82: Expected 1 errors"
   ],
   "generics_syntax_compatibility.py": [],
   "generics_syntax_declarations.py": [],

conformance/third_party/results.json

@@ -3,7 +3,7 @@
   "pass": 123,
   "fail": 15,
   "pass_rate": 0.89,
-  "differences": 42,
+  "differences": 40,
   "passing": [
     "aliases_explicit.py",
     "aliases_newtype.py",
@@ -141,7 +141,7 @@
     "generics_basic.py": 3,
     "generics_paramspec_components.py": 1,
     "generics_scoping.py": 4,
-    "generics_self_usage.py": 3,
+    "generics_self_usage.py": 1,
     "generics_typevartuple_basic.py": 1,
     "protocols_modules.py": 1,
     "qualifiers_final_annotation.py": 3

pyrefly/lib/alt/call.rs

@@ -796,7 +796,13 @@ impl<'a, Ans: LookupAnswer> AnswersSolver<'a, Ans> {
         }
         if let Some(mut ret) = dunder_new_ret {
             ret.subst_mut(&cls.targs().substitution_map());
-            ret
+            if constructor_kind == ConstructorKind::TypeOfSelf
+                && let Type::ClassType(ret_cls) = &ret
+            {
+                self.heap.mk_self_type(ret_cls.clone())
+            } else {
+                ret
+            }
         } else if constructor_kind == ConstructorKind::TypeOfSelf {
             self.heap.mk_self_type(cls)
         } else {
@@ -966,6 +972,10 @@ impl<'a, Ans: LookupAnswer> AnswersSolver<'a, Ans> {
                     context,
                     hint,
                 );
+                eprintln!(
+                    "Constructed type: {}",
+                    self.for_display(constructed_type.clone())
+                );
                 // Override the constructed type with the quantified bound if
                 // this class is being called via a quantified type with a class
                 // bound, to allow calls on TypeVars with class bounds to work

pyrefly/lib/test/typing_self.rs

@@ -312,16 +312,15 @@ class B(A[Y1 | Y2], Generic[Y1, Y2]):
 );
 
 testcase!(
-    bug = "should not error",
     test_self_return_in_classmethod,
     r#"
 from typing import Self
 class C:
     @classmethod
     def bar(cls) -> Self:
-        return cls(1) # E: Returned type `C` is not assignable to declared return type `Self@C`
+        return cls(1)
 
     def __new__(cls, value: int) -> Self:  # Accepted
-        return cls(1) # E: Returned type `C` is not assignable to declared return type `Self@C`
+        return cls(1)
 "#,
 );