Eval lua script expects return integer but null

[CodePlayer]

Bug Report

Current Behavior

There is a string key named a, which value is 1 in Redis. I want to read the value as Long by lua script. However, it returns null unexpectedlly.

Input Code

// code example
final RedisCommands<String, String> redisCommands = redisClient.connect().sync();
redisCommands.set("a", "1"); // SET a 1

String luaScript = "return redis.call('GET', KEYS[1])";
Long val = redisCommands.eval(luaScript, ScriptOutputType.INTEGER, "a");
System.out.println(val); // expect output "1" but "null"

Expected behavior/code

return 1 as expected ( OR maybe throw exception ) . Does NOT return null silently.

Environment

• Lettuce version(s): 6.1.9.RELEASE
• Redis version: 6.0.14

Possible Solution

Enhance type conversion compatibility. Throw an exception when the types are still not compatible.

Additional context

BTW, Redisson client works well in same situation.