Function effect

packages/reactivity/src/effect.ts:484–505

(
  fn: () => T,
  options?: ReactiveEffectOptions,
)

}

export function effect<T = any>(
  fn: () => T,
  options?: ReactiveEffectOptions,
): ReactiveEffectRunner<T> {
  if ((fn as ReactiveEffectRunner).effect instanceof ReactiveEffect) {
    fn = (fn as ReactiveEffectRunner).effect.fn
  }

  const e = new ReactiveEffect(fn)
  if (options) {
    extend(e, options)
  }
  try {
    e.run()
  } catch (err) {
    e.stop()
    throw err
  }
  const runner = e.run.bind(e) as ReactiveEffectRunner
  runner.effect = e
  return runner
}

/**
 * Stops the effect associated with the given runner.