From a7615d0c68d847cfd8a42c992df32390b5931e01 Mon Sep 17 00:00:00 2001
From: nicholaspai <9457025+nicholaspai@users.noreply.github.com>
Date: Thu, 2 Jan 2025 10:49:34 -0500
Subject: [PATCH] feat(BundleDataClient): Remove 0-value deposits and fills and
 0-value empty-message slow fills (#800)

---
 package.json                                  |  2 +-
 .../BundleDataClient/BundleDataClient.ts      | 19 +++++++++++++++++--
 src/utils/DepositUtils.ts                     | 12 ++++++++++++
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index 62577d2ea..f1eefac80 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@across-protocol/sdk",
   "author": "UMA Team",
-  "version": "3.3.31",
+  "version": "3.3.32",
   "license": "AGPL-3.0",
   "homepage": "https://docs.across.to/reference/sdk",
   "files": [
diff --git a/src/clients/BundleDataClient/BundleDataClient.ts b/src/clients/BundleDataClient/BundleDataClient.ts
index 22c7ecb34..fd992c95d 100644
--- a/src/clients/BundleDataClient/BundleDataClient.ts
+++ b/src/clients/BundleDataClient/BundleDataClient.ts
@@ -31,6 +31,7 @@ import {
   isSlowFill,
   mapAsync,
   bnUint32Max,
+  isZeroValueDeposit,
 } from "../../utils";
 import winston from "winston";
 import {
@@ -778,6 +779,9 @@ export class BundleDataClient {
           continue;
         }
         originClient.getDepositsForDestinationChain(destinationChainId).forEach((deposit) => {
+          if (isZeroValueDeposit(deposit)) {
+            return;
+          }
           depositCounter++;
           const relayDataHash = this.getRelayHashFromEvent(deposit);
           if (v3RelayHashes[relayDataHash]) {
@@ -793,6 +797,14 @@ export class BundleDataClient {
             slowFillRequest: undefined,
           };
 
+          // Once we've saved the deposit hash into v3RelayHashes, then we can exit early here if the inputAmount
+          // is 0 because there can be no expired amount to refund and no unexecutable slow fill amount to return
+          // if this deposit did expire. Input amount can only be zero at this point if the message is non-empty,
+          // but the message doesn't matter for expired deposits and unexecutable slow fills.
+          if (deposit.inputAmount.eq(0)) {
+            return;
+          }
+
           // If deposit block is within origin chain bundle block range, then save as bundle deposit.
           // If deposit is in bundle and it has expired, additionally save it as an expired deposit.
           // If deposit is not in the bundle block range, then save it as an older deposit that
@@ -840,7 +852,10 @@ export class BundleDataClient {
         await forEachAsync(
           destinationClient
             .getFillsForOriginChain(originChainId)
-            .filter((fill) => fill.blockNumber <= destinationChainBlockRange[1]),
+            // We can remove fills for deposits with input amount equal to zero because these will result in 0 refunded
+            // tokens to the filler. We can't remove non-empty message deposit here in case there is a slow fill
+            // request for the deposit, we'd want to see the fill took place.
+            .filter((fill) => fill.blockNumber <= destinationChainBlockRange[1] && !isZeroValueDeposit(fill)),
           async (fill) => {
             const relayDataHash = this.getRelayHashFromEvent(fill);
             fillCounter++;
@@ -933,7 +948,7 @@ export class BundleDataClient {
         await forEachAsync(
           destinationClient
             .getSlowFillRequestsForOriginChain(originChainId)
-            .filter((request) => request.blockNumber <= destinationChainBlockRange[1]),
+            .filter((request) => request.blockNumber <= destinationChainBlockRange[1] && !isZeroValueDeposit(request)),
           async (slowFillRequest: SlowFillRequestWithBlock) => {
             const relayDataHash = this.getRelayHashFromEvent(slowFillRequest);
 
diff --git a/src/utils/DepositUtils.ts b/src/utils/DepositUtils.ts
index 59ab124c0..5dd97aec2 100644
--- a/src/utils/DepositUtils.ts
+++ b/src/utils/DepositUtils.ts
@@ -125,6 +125,18 @@ export async function queryHistoricalDepositForFill(
   };
 }
 
+/**
+ * Returns true if filling this deposit (as a slow or fast fill) or refunding it would not change any state
+ * on-chain. The dataworker functions can use this to conveniently filter out useless deposits.
+ * @dev The reason we allow a 0-input deposit to have a non-empty message is that the message might be used
+ * to pay the filler in an indirect way so it might have economic value as a fast or slow fill.
+ * @param deposit Deposit to check.
+ * @returns True if deposit's input amount is 0 and message is empty.
+ */
+export function isZeroValueDeposit(deposit: Pick<Deposit, "inputAmount" | "message">): boolean {
+  return deposit.inputAmount.eq(0) && isMessageEmpty(deposit.message);
+}
+
 /**
  * Determines if a message is empty or not.
  * @param message The message to check.