Confusion caused by a cookie

In the previous point redemption system, an error occurs: the user can redeem the gift if the user has 0 or negative points. Check redemption submissionProgram. This problem occurs again today, only to find that the browser window is not closed, multiple users log on, resulting in incorrect information recorded by the shopping basket cookies. Our testing program is in an ideal state, so we can't always find errors. Users can operate in unexpected circumstances and the problem occurs. This issue reminds us that 1. The testing methods and procedures need to be improved. 2. The client-shared storage method similar to cookies must be logically rigorous, from generation to destruction, to avoid confusion.