getPersistedSnapshot(): resiliency & reliability

[mfulton26]

Is there documentation on what can be expected when using getPersistedSnapshot() when upgrading XState and/or making changes to machines?

I could see scenarios where an XState upgrade could unintentionally change the persisted snapshot schema unless this schema is meant to be stable and is tested against from release to release.

I could also see scenarios where restoring from a persisted snapshot could fail due to non-backward-compatible changes in a machine's definition (e.g. state removed… what else could cause problems?).

I think it would be nice to have a list of things that developers can rely on and things they should be aware of (e.g. gotchas) when using persisted snapshots, recommendations on how to detect and recover from unexpected behavior/errors, etc.