Fix trailing undefined for optional parameters not omitted with @send

CHANGELOG.md

@@ -19,8 +19,8 @@
 #### :bug: Bug Fix
 
 - Improve error when using '@deriving(accessors)' on a variant with record arguments. https://github.com/rescript-lang/rescript-compiler/pull/6712
-
 - Stop escaping JSX prop names with hyphens. https://github.com/rescript-lang/rescript-compiler/pull/6705
+- Fix trailing undefined for optional parameters not omitted with `@send`. https://github.com/rescript-lang/rescript-compiler/pull/6716
 
 # 11.1.0-rc.7
 

jscomp/core/lam_compile_external_call.ml

@@ -250,6 +250,16 @@ let translate_scoped_access scopes obj =
   | [] -> obj
   | x :: xs -> Ext_list.fold_left xs (E.dot obj x) E.dot
 
+let keep_non_undefined_args args arg_types =
+  let rec aux argsList (argTypes : specs) =
+    match (argsList, argTypes) with
+    | ( {J.expression_desc = Undefined {isUnit = false}; _} :: rest,
+        {External_arg_spec.arg_label = Arg_optional; _} :: argTypes ) ->
+          aux rest argTypes
+    | _ -> argsList
+  in
+  aux (List.rev args) (List.rev arg_types) |> List.rev
+
 let translate_ffi (cxt : Lam_compile_context.t) arg_types
     (ffi : External_ffi_types.external_spec) (args : J.expression list) ~dynamic_import =
   match ffi with
@@ -271,16 +281,7 @@ let translate_ffi (cxt : Lam_compile_context.t) arg_types
           else E.call ~info:{ arity = Full; call_info = Call_na } fn args)
       else
         let args, eff = assemble_args_no_splice arg_types args in
-        let rec keepNonUndefinedArgs argsList (argTypes : specs) =
-          match (argsList, argTypes) with
-          | ( {J.expression_desc = Undefined {isUnit = false}; _} :: rest,
-              {External_arg_spec.arg_label = Arg_optional; _} :: argTypes ) ->
-            keepNonUndefinedArgs rest argTypes
-          | _ -> argsList
-        in
-        let args =
-          keepNonUndefinedArgs (List.rev args) (List.rev arg_types) |> List.rev
-        in
+        let args = keep_non_undefined_args args arg_types in
         add_eff eff
         @@ E.call ~info:{ arity = Full; call_info = Call_na } fn args
   | Js_module_as_fn { external_module_name; splice } ->
@@ -341,6 +342,7 @@ let translate_ffi (cxt : Lam_compile_context.t) arg_types
                    (E.dot self name) args)
           else
             let args, eff = assemble_args_no_splice arg_types args in
+            let args = keep_non_undefined_args args arg_types in
             add_eff eff
               (let self = translate_scoped_access js_send_scopes self in
                E.call

jscomp/runtime/release.ninja

@@ -25,7 +25,7 @@ o runtime/caml_exceptions.cmj : cc_cmi runtime/caml_exceptions.res | runtime/cam
 o runtime/caml_exceptions.cmi : cc runtime/caml_exceptions.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_float.cmj : cc_cmi runtime/caml_float.res | runtime/caml_float.cmi runtime/caml_float_extern.cmj
 o runtime/caml_float.cmi : cc runtime/caml_float.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
-o runtime/caml_format.cmj : cc_cmi runtime/caml_format.ml | runtime/caml_float.cmj runtime/caml_float_extern.cmj runtime/caml_format.cmi runtime/caml_int64.cmj runtime/caml_int64_extern.cmj runtime/caml_nativeint_extern.cmj runtime/caml_string_extern.cmj
+o runtime/caml_format.cmj : cc_cmi runtime/caml_format.ml | runtime/caml.cmj runtime/caml_float.cmj runtime/caml_float_extern.cmj runtime/caml_format.cmi runtime/caml_int64.cmj runtime/caml_int64_extern.cmj runtime/caml_nativeint_extern.cmj runtime/caml_string_extern.cmj
 o runtime/caml_format.cmi : cc runtime/caml_format.mli | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_hash.cmj : cc_cmi runtime/caml_hash.res | runtime/caml_hash.cmi runtime/caml_hash_primitive.cmj runtime/caml_nativeint_extern.cmj runtime/js.cmj
 o runtime/caml_hash.cmi : cc runtime/caml_hash.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
@@ -41,7 +41,7 @@ o runtime/caml_md5.cmj : cc_cmi runtime/caml_md5.res | runtime/caml_array_extern
 o runtime/caml_md5.cmi : cc runtime/caml_md5.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_module.cmj : cc_cmi runtime/caml_module.res | runtime/caml_array_extern.cmj runtime/caml_module.cmi runtime/caml_obj.cmj
 o runtime/caml_module.cmi : cc runtime/caml_module.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
-o runtime/caml_obj.cmj : cc_cmi runtime/caml_obj.res | runtime/caml_array_extern.cmj runtime/caml_obj.cmi runtime/caml_option.cmj runtime/js.cmj
+o runtime/caml_obj.cmj : cc_cmi runtime/caml_obj.res | runtime/caml.cmj runtime/caml_array_extern.cmj runtime/caml_obj.cmi runtime/caml_option.cmj runtime/js.cmj
 o runtime/caml_obj.cmi : cc runtime/caml_obj.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_option.cmj : cc_cmi runtime/caml_option.res | runtime/caml_option.cmi runtime/caml_undefined_extern.cmj runtime/js.cmj
 o runtime/caml_option.cmi : cc runtime/caml_option.resi | runtime/bs_stdlib_mini.cmi runtime/caml_undefined_extern.cmj runtime/js.cmi runtime/js.cmj
@@ -58,7 +58,7 @@ o runtime/caml_bigint_extern.cmi runtime/caml_bigint_extern.cmj : cc runtime/cam
 o runtime/caml_external_polyfill.cmi runtime/caml_external_polyfill.cmj : cc runtime/caml_external_polyfill.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_float_extern.cmi runtime/caml_float_extern.cmj : cc runtime/caml_float_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_int64_extern.cmi runtime/caml_int64_extern.cmj : cc runtime/caml_int64_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
-o runtime/caml_js_exceptions.cmi runtime/caml_js_exceptions.cmj : cc runtime/caml_js_exceptions.res | runtime/bs_stdlib_mini.cmi runtime/caml_exceptions.cmj runtime/js.cmi runtime/js.cmj
+o runtime/caml_js_exceptions.cmi runtime/caml_js_exceptions.cmj : cc runtime/caml_js_exceptions.res | runtime/bs_stdlib_mini.cmi runtime/caml_exceptions.cmj runtime/caml_option.cmj runtime/js.cmi runtime/js.cmj
 o runtime/caml_nativeint_extern.cmi runtime/caml_nativeint_extern.cmj : cc runtime/caml_nativeint_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_string_extern.cmi runtime/caml_string_extern.cmj : cc runtime/caml_string_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_undefined_extern.cmi runtime/caml_undefined_extern.cmj : cc runtime/caml_undefined_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj

jscomp/test/omit_trailing_undefined_in_external_calls.res

@@ -9,3 +9,7 @@ external formatDate: (Js.Date.t, ~options: dateFormatOptions=?, ~done: bool=?) =
 let x = formatDate(Js.Date.make())
 let x = formatDate(Js.Date.make(), ~options={someOption: true})
 let x = formatDate(Js.Date.make(), ~done=true)
+
+@send external toString: (float, ~radix: int=?) => string = "toString"
+
+let x = toString(42.)