Function: batch()

Imported from @react-logic/state

batch<T>(fn): T

Defined in: state/src/lib/state.ts:53

Coalesce multiple signal writes into a single notification pass. Inside the callback, subscribers (effects, useLogic re-renders) don't fire on each individual write — they fire once at the end with the final values.

Nests safely (uses alien-signals' depth counter under the hood) and runs the final flush in a try/finally, so a thrown exception inside the callback still closes the batch.

Use it when:

• A method writes several related fields and you want consumers to see one consistent snapshot, not an intermediate state with only half updated.
• You're applying a list of changes in a loop and want to avoid the re-render storm.

Don't use it when:

• The writes are already sequential within a single synchronous callback that doesn't itself read signals between writes — alien-signals already coalesces those at the React render boundary.

Type Parameters

T

T

The callback's return type, forwarded through.

Parameters

fn

() => T

The work to perform inside the batch.

Returns

T

Whatever fn returns.

Example

class Form {
  name = state('');
  email = state('');
  age = state(0);

  reset() {
    batch(() => {
      this.name('');
      this.email('');
      this.age(0);
    });
    // Subscribers see exactly one update with all three values reset.
  }
}