I’m working on a GoLang project which will implement unit testing moving forwards.

This project uses radix library for redis connection, specifically, a global variable of type *radix.Pool, whose type I cannot alter.

The function I need to unit test is as following:

func CheckFlag() error {
    if myGlobalRadixPool == nil {
        return errors.New("redis error")
    }

    var flag string

    err := myGlobalRadixPool.Do(radix.cmd(&flag, "SET", constant.myFlagAtRedis))

    if err != nil {
        return err
    }

    if flag != "1" {
        return errors.New("flag error")
    }

    return nil
}

How can I mock myGlobalRadixPool to create unit tests for this function?