fix: access private queue through _self proxy and guard client close calls

Author: PavelPashov

packages/client/lib/client/commands-queue.ts

@@ -591,6 +591,10 @@ export default class RedisCommandsQueue {
    * Prepends commands to the write queue in reverse.
    */
   prependCommandsToWrite(commands: CommandToWrite[]) {
+    if (!commands.length) {
+      return;
+    }
+
     for (let i = commands.length - 1; i <= 0; i--) {
       this.#toWrite.unshift(commands[i]);
     }

packages/client/lib/client/index.ts

@@ -1018,7 +1018,7 @@ export default class RedisClient<
     * @internal
     */
    _getQueue(): RedisCommandsQueue {
-     return this.#queue;
+     return this._self.#queue;
    }
 
   /**

packages/client/lib/cluster/cluster-slots.ts

@@ -371,9 +371,13 @@ export default class RedisClusterSlots<
         this.nodeByAddress.delete(sourceAddress);
 
         // 4.3 Kill because no slots are pointing to it anymore
-        await sourceNode.client?.close()
+        if (sourceNode.client?.isOpen) {
+          await sourceNode.client?.close()
+        }
         if('pubSub' in sourceNode) {
-          await sourceNode.pubSub?.client.close();
+          if (sourceNode.pubSub?.client.isOpen) {
+            await sourceNode.pubSub?.client.close();
+          }
         }
       }