xstate@6.0.0-alpha.39

Patch Changes

• 7a7e564: Fixed a bug where enq.subscribeTo(…) and enq.listen(…) silently did nothing when called inside a transition function. They now work the same as in entry actions:

  const machine = createMachine({
    on: {
      start: (_, enq) => {
        const child = enq.spawn(childLogic);
        enq.subscribeTo(child, {
          done: (output) => ({ type: 'childDone', output })
        });
      },
      childDone: ({ event }) => {
        // event.output is the child's output
      }
    }
  });

• 4e6dbfd: Named imports from the root xstate entry (such as the actor logic creators and SpecialTargets) now work in all environments, including tools that load the package as CommonJS.

  import { createAsyncLogic } from 'xstate'; // now works everywhere

• 20a52b9: Optional event payload fields declared with types() are now preserved instead of being made required:

  const machine = setup({
    schemas: {
      events: {
        submit: types<{ email: string; referrer?: string }>()
      }
    }
  }).createMachine({
    // ...
  });
  
  // referrer can now be omitted
  actor.send({ type: 'submit', email: 'a@b.co' });

  Payloads inferred from validator libraries (e.g. Zod) are still wrapped in Required<>.

• 20a52b9: snapshot.value is now structurally typed from the machine config instead of the generic StateValue type. Flat machines get a union of state keys, and parallel machines get an object type with a key per region:

  const machine = createMachine({
    type: 'parallel',
    states: {
      bold: { initial: 'off', states: { off: {}, on: {} } },
      italic: { initial: 'off', states: { off: {}, on: {} } }
    }
  });
  
  const value = createActor(machine).getSnapshot().value;
  // { bold: 'off' | 'on'; italic: 'off' | 'on' }

• 90a173a: Fixed createSystem(...).setup(...) to preserve runtime validator types alongside typed actor registries. Validated setups now reject unsupported transforming schemas and carry validation into derived setups.

  Runtime validation can now also be installed on a derived setup when its inherited schemas are compatible:

  import { setup } from 'xstate';
  import { standardSchemaValidator } from 'xstate/validation';
  import { z } from 'zod';
  
  const validated = setup({
    schemas: { input: z.object({ id: z.string() }) }
  }).extend({ validator: standardSchemaValidator() });