Adds reorg detection within RPCs reponse. (#171)

* Adds reorg detection within RPCs reponse.

* Bugfix: Adds checks for newBlocks size.

---------

Co-authored-by: Andrés Elizondo <[email protected]>

Author: AndresElizondo

src/scripts/pull_and_save_block_events.ts

@@ -487,6 +487,18 @@ export class BlockEventsScraper {
             throw Error(`Big reorg detected, of more than ${lookback}, manual intervention needed`);
         }
 
+        // Finding reorgs within RPC's response
+        if (newBlocks.length > 1) {
+            var prevBlock = newBlocks[0];
+            for (const currBlock of newBlocks.slice(1)) {
+                if (currBlock.parentHash !== prevBlock.hash) {
+                    logger.warn(`Reorg detected within RPC's response. Ignoring invalid response and retrying.`);
+                    return;
+                }
+                prevBlock = currBlock;
+            }
+        }
+
         try {
             const tmpBlockNumbers = newBlocks.map((block) => block?.number);
             logger.debug(`response blockNumbers: ${JSON.stringify(tmpBlockNumbers)}`);