From 94442423a9159a8cdaa60d4a6e7b7e13c95a6ebb Mon Sep 17 00:00:00 2001
From: Carter Green <carter@databento.com>
Date: Fri, 5 Jan 2024 14:20:07 -0600
Subject: [PATCH] MOD: Improve `RecordRef::get` panic message

---
 CHANGELOG.md               | 2 ++
 rust/dbn/src/record_ref.rs | 4 +++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 56cdd35..e15f297 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,8 @@
 - Added Python type definition for `Metadata.__init__`
 - Added `metadata_mut` method to decoders to get a mutable reference to the decoded
   metadata
+- Improved panic message on `RecordRef::get` when length doesn't match expected to be
+  actionable
 - Added `encode::ZSTD_COMPRESSION_LEVEL` constant
 
 ### Breaking changes
diff --git a/rust/dbn/src/record_ref.rs b/rust/dbn/src/record_ref.rs
index d26db92..b0841d1 100644
--- a/rust/dbn/src/record_ref.rs
+++ b/rust/dbn/src/record_ref.rs
@@ -77,7 +77,9 @@ impl<'a> RecordRef<'a> {
         if self.has::<T>() {
             assert!(
                 self.record_size() >= mem::size_of::<T>(),
-                "Malformed record. Expected length of at least {} bytes, found {} bytes",
+                "Malformed `{}` record: expected length of at least {} bytes, found {} bytes. \
+                Confirm the DBN version in the Metadata header and the version upgrade policy",
+                std::any::type_name::<T>(),
                 mem::size_of::<T>(),
                 self.record_size()
             );