Correct location in mapping

Author: nojaf

compiler/ml/ast_mapper_to0.ml

@@ -288,15 +288,6 @@ module E = struct
     let loc = sub.location sub loc in
     let attrs = sub.attributes sub attrs in
     match desc with
-    | Pexp_jsx_fragment (_, xs, _) ->
-      (* TODO: tweak location slightly *)
-      let list_expr = Ast_helper.Exp.make_list_expression loc xs None in
-      let mapped = sub.expr sub list_expr in
-      let jsx_attr =
-        sub.attribute sub (Location.mknoloc "JSX", Parsetree.PStr [])
-      in
-      {mapped with pexp_attributes = jsx_attr :: attrs}
-      (* failwith "TODO Pexp_jsx_fragment 4" *)
     | Pexp_ident x -> ident ~loc ~attrs (map_loc sub x)
     | Pexp_constant x -> constant ~loc ~attrs (map_constant x)
     | Pexp_let (r, vbs, e) ->
@@ -416,6 +407,18 @@ module E = struct
     | Pexp_open (ovf, lid, e) ->
       open_ ~loc ~attrs ovf (map_loc sub lid) (sub.expr sub e)
     | Pexp_extension x -> extension ~loc ~attrs (sub.extension sub x)
+    | Pexp_jsx_fragment (o, xs, c) ->
+      (*
+         The location of  Pexp_jsx_fragment is from the start of < till the end of />.
+         This is not the case in the old AST. There it is from >...</
+      *)
+      let loc = {loc with loc_start = o; loc_end = c} in
+      let list_expr = Ast_helper.Exp.make_list_expression loc xs None in
+      let mapped = sub.expr sub list_expr in
+      let jsx_attr =
+        sub.attribute sub (Location.mknoloc "JSX", Parsetree.PStr [])
+      in
+      {mapped with pexp_attributes = jsx_attr :: attrs}
 end
 
 module P = struct