From a7e4902ab79e28340f55e1db4444da3e7adbbc65 Mon Sep 17 00:00:00 2001
From: Thaddeus <thad@tardis.dev>
Date: Mon, 10 Jun 2024 10:12:59 +0200
Subject: [PATCH] improvement: handle dydx book change mapping more gracefully
 when no offsets are available

---
 src/mappers/dydx.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/mappers/dydx.ts b/src/mappers/dydx.ts
index 5040401..6873e1e 100644
--- a/src/mappers/dydx.ts
+++ b/src/mappers/dydx.ts
@@ -97,7 +97,7 @@ export class DydxBookChangeMapper implements Mapper<'dydx', BookChange> {
 
         bids: message.contents.bids
           .map((bid) => {
-            const lastPriceLevelOffset = this._bidsOffsets[message.id][bid[0]]
+            const lastPriceLevelOffset = this._bidsOffsets[message.id] && this._bidsOffsets[message.id][bid[0]]
             if (lastPriceLevelOffset !== undefined && lastPriceLevelOffset >= updateOffset) {
               return
             }
@@ -111,7 +111,7 @@ export class DydxBookChangeMapper implements Mapper<'dydx', BookChange> {
 
         asks: message.contents.asks
           .map((ask) => {
-            const lastPriceLevelOffset = this._asksOffsets[message.id][ask[0]]
+            const lastPriceLevelOffset = this._asksOffsets[message.id] && this._asksOffsets[message.id][ask[0]]
             if (lastPriceLevelOffset !== undefined && lastPriceLevelOffset >= updateOffset) {
               return
             }