Batching

Updates run in a microtask

A signal write does not touch the DOM right away. Signy collects the changes and applies them in a microtask, so several writes in a row cause one update.

batch()

batch() groups writes explicitly. Readers run once, after the function returns, and see the final values.

batch(() => {
  this.firstName.value = 'Ada';
  this.lastName.value = 'Lovelace';
});

flushAll()

flushAll() runs every pending notification, effect and DOM update right away. Use it in tests after a write. See Testing.

count.value = 2;
flushAll();
expect(root.textContent).toBe('2');

flushSync() only delivers signal notifications. It does not run effects or DOM updates, so prefer flushAll().