chore(state) expose __none__ state

[lidio601]

Motivation

I'm listening to a state onEnter event to perform some database changes when a transition happens.

I noticed that this event was triggered also just after the stm.start(initialState); line.

To cope with this event and ignore this first initial transition I checked the source code and found that this event has a stub __none__ state.

So in my code I ended up with this:

state.onEnter((change) {
  if (change.from.name != '__none__') {
    // do something
  }
});

I think this is not the best approach as I'm relying on some internal representation.
That's why I'm exposing this State.isNone getter.

Changes

• State.isNone getter added
• StateChange.isInitial

Release Notes

Exposed State.isNone and StateChange.isInitial to distinguish initial state change events.

Review

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QA Checklist

• Tests were updated and provide good coverage of the changeset and other affected code
• Manual testing was performed if needed
  • Steps from PR author:
  • Anything falling under manual testing criteria outlined in CONTRIBUTING.md

Merge Checklist

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• A Client Platform member has reviewed these changes
• There are no unaddressed comments - this check can be automated if reviewers use the "Request Changes" feature
• For release PRs - Version metadata in Rosie comment is correct

[aviary-wf]

Security Insights

No security relevant content was detected by automated scans.

Action Items

• Review PR for security impact; comment "security review required" if needed or unsure
• Verify aviary.yaml coverage of security relevant code

---

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[maxwellpeterson-wf]

@evanweible-wf

[lidio601]

hi there, how's going with this one?

[evanweible-wf]

Instead of adding isNone to the API for every State instance, could we add a static field to represent the none state and use that? Then the isInitial getter below could be:

bool get isInitial => from == State.none

[lidio601]

should looks better now

[evanweible-wf]

@lidio601 if you could run dartfmt and commit the changes, we should be able to get this merged. Thanks!