improve(relayer): Catch identifiable re-org events by blockHash

src/clients/SpokePoolClient.ts

@@ -202,30 +202,20 @@ export function SpokeListener<T extends Constructor<MinGenericSpokePoolClient>>(
       const at = "SpokePoolClient#removeEvent";
       const eventIdx = this._queryableEventNames().indexOf(event.event);
       const pendingEvents = this.#pendingEvents[eventIdx];
-      const { event: eventName, blockNumber, blockHash, transactionHash, transactionIndex, logIndex } = event;
+      const { event: eventName, blockNumber, blockHash, transactionHash } = event;
 
       // First check for removal from any pending events.
-      const pendingEventIdx = pendingEvents.findIndex(
-        (pending) =>
-          pending.logIndex === logIndex &&
-          pending.transactionIndex === transactionIndex &&
-          pending.transactionHash === transactionHash &&
-          pending.blockHash === blockHash
-      );
-
       let removed = false;
-      if (pendingEventIdx !== -1) {
-        removed = true;
-
-        // Drop the relevant event.
-        pendingEvents.splice(pendingEventIdx, 1);
-
-        this.logger.debug({
-          at: "SpokePoolClient#removeEvent",
-          message: `Removed 1 pre-ingested ${this.#chain} ${eventName} event for block ${blockNumber}.`,
-          event,
-        });
-      }
+      let removedEventIdx: number;
+      do {
+        removedEventIdx = pendingEvents.findIndex(({ blockHash }) => blockHash === event.blockHash);
+        if (removedEventIdx !== -1) {
+          removed = true;
+          pendingEvents.splice(removedEventIdx, 1); // Drop the relevant event.
+          const message = `Removed pre-ingested ${this.#chain} ${eventName} event for block ${blockNumber}.`;
+          this.logger.debug({ at, message, event });
+        }
+      } while (removedEventIdx !== -1);
 
       // Back out any events that were previously ingested via update(). This is best-effort and may help to save the
       // relayer from filling a deposit where it must wait for additional deposit confirmations. Note that this is

test/Relayer.IndexedSpokePoolClient.ts

@@ -180,6 +180,28 @@ describe("IndexedSpokePoolClient: Update", async function () {
     expect(droppedDeposit).to.not.exist;
   });
 
+  it("Correctly removes all pending events for a given blockHash", async function () {
+    const rawEvents: Log[] = [];
+    for (let i = 0; i < 25; ++i) {
+      rawEvents.push(getDepositEvent(blockNumber++));
+    }
+
+    // Modify all events to share the same blockHash.
+    const events = rawEvents.slice(1).map((event) => ({ ...event, blockHash: rawEvents[0].blockHash }));
+    sortEventsAscendingInPlace(events);
+
+    postEvents(blockNumber, currentTime, events);
+
+    const [droppedEvent] = events;
+    removeEvent(droppedEvent);
+
+    await spokePoolClient.update();
+
+    // All events should have been dropped before SpokePoolClient update.
+    const deposits = spokePoolClient.getDeposits();
+    expect(deposits.length).to.equal(0);
+  });
+
   it("Correctly removes pending events that are dropped after update", async function () {
     const events: Log[] = [];
     for (let i = 0; i < 25; ++i) {