Make sure sub expressions don't have par

Author: davesnx

lib/Fmt_ast.ml

@@ -2273,6 +2273,11 @@ and fmt_expression c ?(box = true) ?(pro = noop) ?eol ?parens
   | Pexp_apply (e0, e1N1) -> (
       match pexp_attributes with
       | [{attr_name={txt="JSX";loc=_}; attr_payload=PStr []; _}] ->
+        let is_jsx_element e =
+          match e.pexp_attributes with
+          | [{attr_name={txt="JSX";_}; attr_payload=PStr []; _}] -> true
+          | _ -> false
+        in
         let children = ref None in
         let props = List.filter_map e1N1 ~f:(function
           | Labelled {txt="children";_}, {pexp_desc=Pexp_list es;pexp_loc;_} ->
@@ -2305,11 +2310,6 @@ and fmt_expression c ?(box = true) ?(pro = noop) ?eol ?parens
           match props with
           | [] -> str ""
           | props ->
-            let is_jsx_element e =
-              match e.pexp_attributes with
-              | [{attr_name={txt="JSX";_}; attr_payload=PStr []; _}] -> true
-              | _ -> false
-            in
             let fmt_labelled ?(prefix="") label e =
               let flabel = str (Printf.sprintf "%s%s" prefix label.txt) in
               match e.pexp_desc with
@@ -2338,7 +2338,11 @@ and fmt_expression c ?(box = true) ?(pro = noop) ?eol ?parens
             let children =
               hvbox 0 (
                 list children (break 1 0)
-                (fun e -> fmt_expression c ~parens:false (sub_exp ~ctx e))
+                (fun e ->
+                  if is_jsx_element e then
+                    fmt_expression c ~parens:false (sub_exp ~ctx e)
+                  else
+                    fmt_expression c (sub_exp ~ctx e))
                 $ Cmts.fmt_after c children_loc)
             in
             hvbox 2 (head $ break 0 0 $ children $ break 0 (-2) $ end_tag ())

test/mlx/mlx.t

@@ -180,3 +180,15 @@ JSX elements as props:
   let _ = <div element=(<Componient />) />
   $ echo 'let _ = <Big element=(<Component />) />' | fmt
   let _ = <Big element=(<Component />) />
+
+  $ echo 'let _ = <Big>(<Component />)</Big>' | fmt
+  let _ = <Big><Component /></Big>
+
+  $ echo 'let _ = <Big>(React.string children)</Big>' | fmt
+  let _ = <Big>(React.string children)</Big>
+
+  $ echo 'let _ = <Big>(match x with | A -> "33" | B -> "44")</Big>' | fmt
+  let _ = <Big>(match x with A -> "33" | B -> "44")</Big>
+
+  $ echo 'let _ = <Big>(<Lola />)</Big>' | fmt
+  let _ = <Big><Lola /></Big>