From 1dbb3d97eb1c728e58fcdbed3504b13a4b62c2dc Mon Sep 17 00:00:00 2001
From: Mike Aizatsky <maizatskyi@cloudflare.com>
Date: Wed, 14 Aug 2024 07:30:55 -0700
Subject: [PATCH] more user-friendly jsg exception message

Strictly speaking this is not backward compatible, but I doubt anyone cares and it has saved me some time while debugging an issue.
---
 src/workerd/jsg/struct.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/workerd/jsg/struct.h b/src/workerd/jsg/struct.h
index 31482bb470b..fc6c4a56191 100644
--- a/src/workerd/jsg/struct.h
+++ b/src/workerd/jsg/struct.h
@@ -103,8 +103,9 @@ class StructWrapper<Self, T, TypeTuple<FieldWrappers...>, kj::_::Indexes<indices
                      kj::isSameType<typename FieldWrappers::Type, Unimplemented>()) && ...)) {
         return T{};
       }
-      jsg::throwTypeError(isolate, "Cannot initialize a dictionary with required members from an "
-                                    "undefined or null value.");
+      jsg::throwTypeError(isolate, kj::str("Cannot initialize ", typeid(T).name(),
+                                           " with required members from an "
+                                           "undefined or null value."));
     }
 
     if (!handle->IsObject()) return kj::none;