Handling errors in guards

[ninjz]

I have guard functions which perform computations that rely on calling other functions that may result in null/undefined values. Returning null/undefined values should not happen if the system is defined correctly however calling these functions throws ts errors for not doing these checks.

Currently I guess I can just always return false in these checks but I want to know what is the best practice for handling errors within guards? Would it be to just return false in those cases or to throw an error? Or should I somehow transition the state machine to some error state?

[melishev]

This is actually a good question, and it's not clear to me why after all this time the creators of Xstate haven't dedicated a chapter to it in the documentation.

As I understand it at the moment, a fsm should work in such a way that if there are incorrect calculations outside the fsm, you should:

1. handle them in a way that is specific to you (e.g. just send events from the fsm to the application and handle them yourself).
2. Return false and pretend that no error occurred