starknet_os: make sure the virtual output iterator is fully consumed

Author: Yoni-Starkware

crates/starknet_os/src/io/os_output.rs

@@ -47,6 +47,8 @@ pub enum OsOutputError {
     InvalidOsOutputField { value_name: String, val: Felt, message: String },
     #[error("Failed to convert to FullOsOutput. State diff variant is of a different type")]
     ConvertToFullOutput,
+    #[error("Output iterator not exhausted.")]
+    OutputNotExhausted,
 }
 
 pub(crate) fn wrap_missing<T>(val: Option<T>, val_name: &str) -> Result<T, OsOutputError> {

crates/starknet_os/src/io/virtual_os_output.rs

@@ -36,6 +36,10 @@ impl VirtualOsOutput {
         let starknet_os_config_hash = wrap_missing(iter.next(), "starknet_os_config_hash")?;
         let messages_to_l1 = parse_messages_to_l1(&mut iter)?;
 
+        if iter.next().is_some() {
+            return Err(OsOutputError::OutputNotExhausted);
+        }
+
         Ok(Self {
             version,
             base_block_number,