remove unnecessary parens

Author: cometkim

jscomp/core/js_dump.ml

@@ -163,7 +163,7 @@ let raw_snippet_exp_simple_enough (s : string) =
 let exp_need_paren (e : J.expression) =
   match e.expression_desc with
   (* | Caml_uninitialized_obj _  *)
-  | Call ({ expression_desc = Fun _ | Raw_js_code _ }, _, _) -> true
+  | Call ({ expression_desc = Raw_js_code _ }, _, _) -> true
   | Raw_js_code { code_info = Exp _ }
   | Fun _
   | Caml_block
@@ -301,7 +301,7 @@ let rec try_optimize_curry cxt f len function_id =
   Curry_gen.pp_optimize_curry f len;
   P.paren_group f 1 (fun _ -> expression ~level:1 cxt f function_id)
 
-and pp_function ~return_unit ~async ~is_method ?directive cxt (f : P.t) ~fn_state
+and pp_function ~return_unit ~async ~is_method ~need_paren ?directive cxt (f : P.t) ~fn_state
     (l : Ident.t list) (b : J.block) (env : Js_fun_env.t) : cxt =
   match b with
   | [
@@ -410,7 +410,7 @@ and pp_function ~return_unit ~async ~is_method ?directive cxt (f : P.t) ~fn_stat
                 param_body ()
             | No_name { single_arg } ->
                 (* see # 1692, add a paren for annoymous function for safety  *)
-                P.cond_paren_group f (not single_arg) (fun _ ->
+                P.cond_paren_group f (need_paren && not single_arg) (fun _ ->
                     P.string f (L.function_ ~async ~arrow);
                     param_body ())
             | Name_non_top x ->
@@ -510,8 +510,10 @@ and expression_desc cxt ~(level : int) f x : cxt =
           expression ~level:0 cxt f e2)
   | Fun { is_method; params; body; env; return_unit; async; directive } ->
       (* TODO: dump for comments *)
-      pp_function ?directive ~is_method cxt f ~fn_state:default_fn_exp_state params body
-        env ~return_unit ~async
+      pp_function ?directive ~is_method ~return_unit ~async
+        ~need_paren:true
+        ~fn_state:default_fn_exp_state
+        cxt f params body env
       (* TODO:
          when [e] is [Js_raw_code] with arity
          print it in a more precise way
@@ -544,9 +546,10 @@ and expression_desc cxt ~(level : int) f x : cxt =
                              };
                        };
                       ] ->
-                          pp_function ?directive ~is_method ~return_unit ~async cxt f
+                          pp_function ?directive ~is_method ~return_unit ~async
+                            ~need_paren:false
                             ~fn_state:(No_name { single_arg = true })
-                            params body env
+                            cxt f params body env
                       | _ ->
                         let el = match el with
                         | [e] when e.expression_desc = Undefined {is_unit = true} ->
@@ -947,9 +950,10 @@ and variable_declaration top cxt f (variable : J.variable_declaration) : cxt =
       | _ -> (
           match e.expression_desc with
           | Fun { is_method; params; body; env; return_unit; async; directive } ->
-              pp_function ?directive ~is_method cxt f ~return_unit ~async
+              pp_function ?directive ~is_method ~return_unit ~async
+                ~need_paren:false 
                 ~fn_state:(if top then Name_top name else Name_non_top name)
-                params body env
+                cxt f params body env
           | _ ->
               let cxt = pp_var_assign cxt f name in
               let cxt = expression ~level:1 cxt f e in
@@ -1157,8 +1161,10 @@ and statement_desc top cxt f (s : J.statement_desc) : cxt =
       match e.expression_desc with
       | Fun { is_method; params; body; env; return_unit; async; directive } ->
           let cxt =
-            pp_function ?directive ~return_unit ~is_method ~async cxt f ~fn_state:Is_return
-              params body env
+            pp_function ?directive ~return_unit ~is_method ~async
+              ~need_paren:false
+              ~fn_state:Is_return
+              cxt f params body env
           in
           semi f;
           cxt