lotteria | Simple Lottery React App | Frontend Framework library

I am not an experienced developer (so some people smarter than me could have a better solution), but my proposition is:

I would make the switching logic in a different function, something like messageHandler(msg), and replace the if ... else if statements with a simple switch statement. It will have the same functionality, but the code will look a lot clearer.

Also, for each of the cases, I would just move them into a separate function. This makes it easier to read, test and document. Just put each functionality in a different function, which has a good comment on top and is well-tested. The only drawback I can find is that testing the coupling is going to be a pain (if you do it), but for me, the benefits outweigh the losses.

A more advanced way of doing it (if you want to offer flexibility) is to have a map [key, function], which maps keys to the appropriate functions, which need to be called. This is more complex, but I would not recommend it if you just need a simple solution to this problem.