Type Alias: Cleanup

API / @xmachines/play-dom / Cleanup

type Cleanup = () => void & { [Key in DisposeKey]: () => void };

Defined in: packages/play/src/disposable.ts:66

The release of a subscription. A caller runs it, or a scope releases it.

The type is a function AND a Disposable, so one value serves both forms. A caller that holds the release in a field and runs it from a teardown keeps that code. A caller inside one scope writes using and writes no teardown at all:

// The explicit form. It stays correct.
const stop = watchSignal(count, render);
stop();

// The scoped form. The scope releases it, and an exception releases it too.
{
  using stop = watchSignal(count, render);
  render(count.get());
}

using needs Node 24 or a browser with Explicit Resource Management, and it needs "lib": ["ESNext"] of the consumer. The publishable packages build at target: "esnext" and pass the syntax through, so the bundler of the consumer decides how to emit it. The Cleanup VALUE needs neither: a runtime without Symbol.dispose still calls it as a function, and a consumer that declares a lower lib still reads the type. See DisposeKey for the second half of that.

See

Play RFC