statelyai/xstate xstate@6.0.0-alpha.71

on GitHub

Minor Changes

• 749955a: Observe emitted events from every actor in a system with createSystem({ onEmitted }). The callback receives the source actor and original event, including emissions from invoked and spawned children.

  const system = createSystem({
    onEmitted: ({ actorRef, event }) => {
      analytics.track(`${actorRef.id}.${event.type}`, event);
    }
  });
  
  const root = system.createActor(applicationMachine);
  root.start();

  Use system.onEmitted(listener) for a subscription you can remove with .unsubscribe(). Existing actor.on(...) handlers continue to observe only that actor's emissions.

• 2cac9ae: Keep model traversal paths distinct when state inputs or remembered history differ, and fix published declarations for consumers using exact optional properties with library checking enabled.

  Directed graphs now include static eventless transitions and report function-based destinations that cannot be extracted. The experimental getMachineSerializationDiagnostics(machine) helper identifies values that need runtime bindings or cannot be preserved by machine JSON, including omitted undefined object properties and array entries.

  Add JSON CLI commands for version-matched documentation, inspection, definition validation, effect-free simulation, bounded state assertions, counterexample replay, and structural diffs. Run npx xstate docs --json to find the installed agent guide and API stability manifest. The data-only CLI refuses code expressions and does not execute external effects or claim formal proofs.

Patch Changes

• 2672ea8: Preserve the context of previously captured machine snapshots when entry functions return context patches.

• 29ead0b: Clarify how imported SCXML machines differ from native XState v6 machines, including transition domains, event matching, error handling, and the supported execution profile.

  Fix SCXML executable content ordering: all state exits finish before selected transition content runs, and all transition content finishes before state entry. Scripts can mutate declared arrays and plain objects while preserving previous snapshots.

• 0cd2e26: Reject malformed persisted state values, children, and timers consistently during snapshot parsing and restoration. Invalid snapshots now produce an InvalidSnapshotError instead of an incidental TypeError or plain Error.

  Report unhandled public xstate.* events through onUnhandledEvent and development warnings, including obsolete suffixed lifecycle names such as xstate.done.actor.save.

  Reject the removed parent option passed to createActor with migration guidance. Create child actors through invoke, spawn, or enq.spawn.