add another test

Author: edg-l

crates/common/rlp/encode.rs

@@ -698,6 +698,19 @@ mod tests {
         assert_eq!(encoded.len(), value.length(),);
     }
 
+    #[test]
+    fn u64_lengths_match_encoding_up_to_10k() {
+        for n in 0u64..=10_000 {
+            let mut encoded = Vec::new();
+            n.encode(&mut encoded);
+            assert_eq!(
+                encoded.len(),
+                n.length(),
+                "u64 length mismatch at value {n}"
+            );
+        }
+    }
+
     #[test]
     fn can_encode_u8() {
         let mut encoded = Vec::new();