chainHead: Extend Initialized event to support multiple hashes

Signed-off-by: Alexandru Vasile <[email protected]>

substrate/client/rpc-spec-v2/src/chain_head/chain_head_follow.rs

@@ -231,7 +231,7 @@ where
 		let finalized_block_runtime = self.generate_runtime_event(finalized_block_hash, None);
 
 		let initialized_event = FollowEvent::Initialized(Initialized {
-			finalized_block_hash,
+			finalized_block_hashes: vec![finalized_block_hash],
 			finalized_block_runtime,
 			with_runtime: self.with_runtime,
 		});

substrate/client/rpc-spec-v2/src/chain_head/event.rs

@@ -111,8 +111,8 @@ impl From<ApiError> for RuntimeEvent {
 #[derive(Debug, Clone, PartialEq, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct Initialized<Hash> {
-	/// The hash of the latest finalized block.
-	pub finalized_block_hash: Hash,
+	/// The hash of the lastest finalized blocks.
+	pub finalized_block_hashes: Vec<Hash>,
 	/// The runtime version of the finalized block.
 	///
 	/// # Note
@@ -135,12 +135,12 @@ impl<Hash: Serialize> Serialize for Initialized<Hash> {
 	{
 		if self.with_runtime {
 			let mut state = serializer.serialize_struct("Initialized", 2)?;
-			state.serialize_field("finalizedBlockHash", &self.finalized_block_hash)?;
+			state.serialize_field("finalizedBlockHashes", &self.finalized_block_hashes)?;
 			state.serialize_field("finalizedBlockRuntime", &self.finalized_block_runtime)?;
 			state.end()
 		} else {
 			let mut state = serializer.serialize_struct("Initialized", 1)?;
-			state.serialize_field("finalizedBlockHash", &self.finalized_block_hash)?;
+			state.serialize_field("finalizedBlockHashes", &self.finalized_block_hashes)?;
 			state.end()
 		}
 	}
@@ -348,7 +348,7 @@ mod tests {
 	fn follow_initialized_event_no_updates() {
 		// Runtime flag is false.
 		let event: FollowEvent<String> = FollowEvent::Initialized(Initialized {
-			finalized_block_hash: "0x1".into(),
+			finalized_block_hashes: vec!["0x1".into()],
 			finalized_block_runtime: None,
 			with_runtime: false,
 		});
@@ -373,7 +373,7 @@ mod tests {
 
 		let runtime_event = RuntimeEvent::Valid(RuntimeVersionEvent { spec: runtime.into() });
 		let mut initialized = Initialized {
-			finalized_block_hash: "0x1".into(),
+			finalized_block_hashes: vec!["0x1".into()],
 			finalized_block_runtime: Some(runtime_event),
 			with_runtime: true,
 		};