vant/packages/vant-waterfall/src/event.js

// eslint-disable-next-line import/no-mutable-exports
export let supportsPassive = false;

try {
  const opts = {};
  Object.defineProperty(opts, 'passive', {
    // eslint-disable-next-line getter-return
    get() {
      /* istanbul ignore next */
      supportsPassive = true;
    },
  });
  window.addEventListener('test-passive', null, opts);
  // eslint-disable-next-line no-empty
} catch (e) {}

export function on(target, event, handler, passive = false) {
  target.addEventListener(
    event,
    handler,
    supportsPassive ? { capture: false, passive } : false
  );
}

export function off(target, event, handler) {
  target.removeEventListener(event, handler);
}