Add option to rpc stream to return all accepted blocks (#199)

Author: fracek

change/@apibara-evm-rpc-6e2cbb59-1f5f-4d86-a90f-9490f78afdb1.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "evm-rpc: add option to send all accepted blocks",
+  "packageName": "@apibara/evm-rpc",
+  "email": "francesco@ceccon.me",
+  "dependentChangeType": "patch"
+}

packages/evm-rpc/src/stream-config.ts

@@ -43,6 +43,8 @@ export type EvmRpcStreamOptions = {
   headRefreshIntervalMs?: number;
   /** How often to refresh the finalized block. */
   finalizedRefreshIntervalMs?: number;
+  /** Force sending accepted headers even if no data matched. */
+  alwaysSendAcceptedHeaders?: boolean;
 };
 
 export class EvmRpcStream extends RpcStreamConfig<Filter, Block> {
@@ -237,7 +239,8 @@ export class EvmRpcStream extends RpcStreamConfig<Filter, Block> {
     const shouldSendBlock =
       filter.header === "always" ||
       logs.length > 0 ||
-      (filter.header === "on_data_or_on_new_block" && isAtHead);
+      (filter.header === "on_data_or_on_new_block" && isAtHead) ||
+      this.options.alwaysSendAcceptedHeaders;
 
     if (shouldSendBlock) {
       block = {