more functional design principles

server/utils/asyncLock.js

@@ -5,6 +5,19 @@
 
 const locks = new Map()
 
+/**
+ * Get or create a queue for a lock key.
+ * @param {string} lockKey - Lock key
+ * @returns {Promise<any>} Existing or new queue promise
+ */
+const getOrCreateQueue = (lockKey) => {
+  const existingQueue = locks.get(lockKey)
+  if (existingQueue) return existingQueue
+  const newQueue = Promise.resolve()
+  locks.set(lockKey, newQueue)
+  return newQueue
+}
+
 /**
  * Acquire a lock for a key and execute callback.
  * Only one callback per key executes at a time.
@@ -14,12 +27,7 @@ const locks = new Map()
  */
 export async function acquire(key, callback) {
   const lockKey = String(key)
-  let queue = locks.get(lockKey)
-
-  if (!queue) {
-    queue = Promise.resolve()
-    locks.set(lockKey, queue)
-  }
+  const queue = getOrCreateQueue(lockKey)
 
   const next = queue.then(() => callback()).finally(() => {
     if (locks.get(lockKey) === next) {