Miniredis
Pure Go Redis server for Go unittests
...You can use TTL() to get the TTL (as a time.Duration) of a key. It will return 0 when no TTL is set. Miniredis will use math/rand's global RNG for randomness unless a seed is provided by calling m.Seed(...). If a seed is provided, then miniredis will use its own RNG based on that seed.