Do not push duplicates to Redis queue, simulate unique list behavior

Author: uuggene

src/providers/WorkflowCore.Providers.Redis/Services/RedisQueueProvider.cs

@@ -36,7 +36,13 @@ public async Task QueueWork(string id, QueueType queue)
             if (_redis == null)
                 throw new InvalidOperationException();
 
-            await _redis.ListRightPushAsync(GetQueueName(queue), id, When.Always);
+            var queueName = GetQueueName(queue);
+
+            var insertResult = await _redis.ListInsertBeforeAsync(queueName, id, id);
+            if (insertResult == -1 || insertResult == 0)
+                await _redis.ListRightPushAsync(queueName, id, When.Always);
+            else
+                await _redis.ListRemoveAsync(queueName, id, 1);
         }
 
         public async Task<string> DequeueWork(QueueType queue, CancellationToken cancellationToken)