Don't create quantified vars for dataclass converters

samwgoldman · facebook-github-bot · commit 45135723c9e5 · 2025-09-12T14:17:34.000-07:00
Summary: When we create a fresh quantified var, we need to finalize it. This code was creating the var, but never finalizing it. Happily, in this case we don't need to create vars at all.

Reviewed By: rchen152

Differential Revision: D82337330

fbshipit-source-id: ba291b9299d27e1abc5fa649ccc2bcb729af9240
diff --git a/pyrefly/lib/alt/class/dataclass.rs b/pyrefly/lib/alt/class/dataclass.rs
@@ -379,7 +379,7 @@ impl<'a, Ans: LookupAnswer> AnswersSolver<'a, Ans> {
     fn get_converter_param(&self, converter: &Type) -> Type {
         let converter = {
             if let Type::ClassDef(cls) = converter
-                && let Type::ClassType(instance) = self.instantiate_fresh_class(cls)
+                && let Type::ClassType(instance) = self.promote_silently(cls)
             {
                 let callable = self.constructor_to_callable(&instance);
                 &self.distribute_over_union(&callable, |ty| {

Original file line number	Diff line number	Diff line change
`@@ -379,7 +379,7 @@ impl<'a, Ans: LookupAnswer> AnswersSolver<'a, Ans> {`
`379`	`379`	`fn get_converter_param(&self, converter: &Type) -> Type {`
`380`	`380`	`let converter = {`
`381`	`381`	`if let Type::ClassDef(cls) = converter`
`382`		`- && let Type::ClassType(instance) = self.instantiate_fresh_class(cls)`
	`382`	`+ && let Type::ClassType(instance) = self.promote_silently(cls)`
`383`	`383`	`{`
`384`	`384`	`let callable = self.constructor_to_callable(&instance);`
`385`	`385`	`&self.distribute_over_union(&callable, \|ty\| {`