From 9f0af7328614d05a4616fbc9c405ed6629e79e4c Mon Sep 17 00:00:00 2001
From: Matthew Giannini
 <Matthew Giannini 1274158+mgiannini@users.noreply.github.com>
Date: Thu, 22 Aug 2024 13:12:48 -0400
Subject: [PATCH] es: throw UnsupportedErr if Func.callOn not supported

---
 src/sys/es/fan/Func.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/sys/es/fan/Func.js b/src/sys/es/fan/Func.js
index 1c6c3b91b..399ccf66d 100644
--- a/src/sys/es/fan/Func.js
+++ b/src/sys/es/fan/Func.js
@@ -42,7 +42,10 @@ class Func extends Obj {
     if (f.__method) return f.__method.call(...args);
     return f(...args);
   }
-  static callOn(f, obj, args) { return f.__method.callOn(obj, args); }
+  static callOn(f, obj, args) {
+    if (f.__method) return f.__method.callOn(obj, args);
+    throw UnsupportedErr.make();
+  }
   static callList(f, args) {
     if (f.__method) return f.__method.callList(args);
     return f.apply(null, args);