Merge pull request #241 from flashbots/msozin/flashblocks-rebase-withdrawals_root-fix

Make withdrawals_root optional

Author: avalonche

src/flashblocks/inbound.rs

@@ -46,10 +46,10 @@ impl FlashblocksReceiverService {
             let msg = msg?;
             match msg {
                 Message::Text(text) => {
-                    if let Ok(flashblocks_msg) = serde_json::from_str::<FlashblocksPayloadV1>(&text)
-                    // TODO: Version this
-                    {
-                        self.sender.send(flashblocks_msg).await?;
+                    match serde_json::from_str::<FlashblocksPayloadV1>(&text) {
+                        // TODO: Version this
+                        Ok(flashblocks_msg) => self.sender.send(flashblocks_msg).await?,
+                        Err(e) => error!("Failed to parse inbound flashblock: {}", e),
                     }
                 }
                 _ => continue,

src/flashblocks/primitives.rs

@@ -26,8 +26,9 @@ pub struct ExecutionPayloadFlashblockDeltaV1 {
     pub transactions: Vec<Bytes>,
     /// Array of [`Withdrawal`] enabled with V2
     pub withdrawals: Vec<Withdrawal>,
+    #[serde(skip_serializing_if = "Option::is_none")]
     /// The withdrawals root of the block.
-    pub withdrawals_root: B256,
+    pub withdrawals_root: Option<B256>,
 }
 
 /// Represents the base configuration of an execution payload that remains constant

src/flashblocks/service.rs

@@ -17,6 +17,7 @@ use thiserror::Error;
 use tokio::sync::RwLock;
 use tokio::sync::mpsc;
 use tracing::error;
+
 #[derive(Debug, Error)]
 pub enum FlashblocksError {
     #[error("Missing base payload for initial flashblock")]
@@ -29,6 +30,8 @@ pub enum FlashblocksError {
     InvalidIndex,
     #[error("Missing payload")]
     MissingPayload,
+    #[error("Malformed flashblock")]
+    MalformedFlashblock,
 }
 
 #[derive(Debug, Deserialize, Serialize)]
@@ -158,7 +161,9 @@ impl FlashblockBuilder {
                     },
                     should_override_builder: false,
                     execution_payload: OpExecutionPayloadV4 {
-                        withdrawals_root,
+                        // In version 4 withdrawals_root should be present
+                        withdrawals_root: withdrawals_root
+                            .ok_or(FlashblocksError::MalformedFlashblock)?,
                         payload_inner: execution_payload,
                     },
                     execution_requests: vec![],