Map prop spreading

Author: nojaf

compiler/ml/ast_mapper_from0.ml

@@ -343,6 +343,9 @@ module E = struct
         |> skip_last_two_elements
         |> List.filter_map (fun (lbl, e) ->
                match (lbl, e) with
+               | Asttypes.Noloc.Labelled "_spreadProps", expr ->
+                 Some
+                   (Parsetree.JSXPropSpreading (Location.none, sub.expr sub expr))
                | ( Asttypes.Noloc.Labelled name,
                    {
                      pexp_desc = Pexp_ident {txt = Longident.Lident v};

compiler/ml/ast_mapper_to0.ml

@@ -471,7 +471,8 @@ module E = struct
                  else Asttypes.Noloc.Labelled name.txt
                in
                (label, sub.expr sub value)
-             | _ -> failwith "todo")
+             | JSXPropSpreading (_, value) ->
+               (Asttypes.Noloc.Labelled "_spreadProps", sub.expr sub value))
       in
       let children_expr =
         let loc =