[core] Add setup().createAction(…)

[davidkpiano]

Add setup().createAction(…) helper for type-safe custom actions.
Allow wrapping built-ins with createAction (e.g. createAction(assign(...)) or createAction(raise(...))).

const machineSetup = setup({
  types: {} as {
    context: {
      count: number;
    };
    events: { type: 'inc'; value: number };
  }
});

const action = machineSetup.createAction(({ context, event }) => {
  console.log(context.count, event.value);
});

const incrementAction = machineSetup.createAction(
  assign({ count: ({ context }) => context.count + 1 })
);

const machine = machineSetup.createMachine({
  context: { count: 0 },
  entry: [action, incrementAction]
});

[changeset-bot]

🦋 Changeset detected

Latest commit: 23dda30

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 5 packages

Name	Type
xstate	Minor
@xstate/react	Major
@xstate/solid	Major
@xstate/svelte	Major
@xstate/vue	Major

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR