Add timeout error

frontend/test-client/src/utils/with-timeout.ts

@@ -1,3 +1,5 @@
+import { __debug_locks } from "sync-client";
+
 export async function withTimeout<T>(
     promise: Promise<T>,
     timeoutMs: number,
@@ -8,9 +10,16 @@ export async function withTimeout<T>(
         new Promise<T>((_, reject) =>
             setTimeout(() => {
                 reject(
-                    new Error(`${operationName} timed out after ${timeoutMs}ms`)
+                    new TimeoutError(`${operationName} timed out after ${timeoutMs}ms ${__debug_locks.map(lock => lock.getDebugString()).join(", ")}`)
                 );
             }, timeoutMs)
         )
     ]);
 }
+
+export class TimeoutError extends Error {
+    constructor(message: string) {
+        super(message);
+        this.name = "TimeoutError";
+    }
+}