Disable Unerasable_optional_argument for uncurried functions via the type checker.

In reality this disables also the check for the body, but this check is on the way out so this should be reasonable in practice without over-complicating the error logic.

Author: cristianoc

jscomp/ml/typecore.ml

@@ -2103,13 +2103,18 @@ and type_expect_ ?in_function ?(recarg=Rejected) env sexp ty_expected =
         exp_type = newty (Ttuple (List.map (fun e -> e.exp_type) expl));
         exp_attributes = sexp.pexp_attributes;
         exp_env = env }
+  | Pexp_construct({txt = Lident "Function$"} as lid, sarg) ->
+      let state = Warnings.backup () in
+      let arity = Ast_uncurried.attributes_to_arity sexp.pexp_attributes in
+      let uncurried_typ = Ast_uncurried.make_uncurried_type ~env ~arity (newvar()) in
+      unify_exp_types loc env ty_expected uncurried_typ;
+      (* Disable Unerasable_optional_argument for uncurried functions *)
+      let unerasable_optional_argument = Warnings.number Unerasable_optional_argument in
+      Warnings.parse_options false ("-" ^ string_of_int unerasable_optional_argument);
+      let exp = type_construct env loc lid sarg ty_expected sexp.pexp_attributes in
+      Warnings.restore state;
+      exp
   | Pexp_construct(lid, sarg) ->
-      (match lid.txt with
-      | Lident "Function$" ->
-        let arity = Ast_uncurried.attributes_to_arity sexp.pexp_attributes in
-        let uncurried_typ = Ast_uncurried.make_uncurried_type ~env ~arity (newvar()) in
-        unify_exp_types loc env ty_expected uncurried_typ
-      | _ -> ());
       type_construct env loc lid sarg ty_expected sexp.pexp_attributes
   | Pexp_variant(l, sarg) ->
       (* Keep sharing *)

jscomp/test/uncurried_default.args.res

@@ -17,5 +17,5 @@ let total = withOpt(~x=10, 3)(~z=4, 11)
 let foo1 = (~x=3, ~y) => x+y
 let r1 = foo1(~y=11)
 
-let foo2 = @warning("-16") (~y, ~x=3, ~z=4) => x+y+z
+let foo2 = (~y, ~x=3, ~z=4) => x+y+z
 let r2 = foo2(~y=11)