From 13a43e44bf757fb550417074d71dfe3fc0080e95 Mon Sep 17 00:00:00 2001
From: Bolun Thompson <bolunthompson@ucla.edu>
Date: Sat, 4 Jan 2025 03:55:19 +0900
Subject: [PATCH] Fix subshells nested in var expansion (#7)

The pretty printer printed it as $(()), an arithmetic expansion.
---
 shasta/ast_node.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/shasta/ast_node.py b/shasta/ast_node.py
index c55f629..ce0b292 100644
--- a/shasta/ast_node.py
+++ b/shasta/ast_node.py
@@ -726,7 +726,14 @@ def json(self):
     
     def pretty(self, quote_mode=UNQUOTED):
         param = self.node
-        return "$(" + param.pretty() + ")"
+        body = param.pretty()
+        # to handle $( () )
+        try:
+            if body[0] == "(" and body[-1] == ")":
+                body = f" {body} "
+        except IndexError:
+            pass
+        return "$(" + body + ")"
 
 class AssignNode(AstNode):
     var: str