vant/packages/vant-use/src/useClickAway/index.ts

import { Ref, unref } from 'vue';
import { inBrowser } from '../utils';
import { useEventListener } from '../useEventListener';

export type UseClickAwayOptions = {
  eventName?: string;
};

export function useClickAway(
  target:
    | Element
    | Ref<Element | undefined>
    | Array<Element | Ref<Element | undefined>>,
  listener: EventListener,
  options: UseClickAwayOptions = {}
) {
  if (!inBrowser) {
    return;
  }

  const { eventName = 'click' } = options;

  const onClick = (event: Event) => {
    const targets = Array.isArray(target) ? target : [target];
    const isClickAway = targets.every((item) => {
      const element = unref(item);
      return element && !element.contains(event.target as Node);
    });

    if (isClickAway) {
      listener(event);
    }
  };

  useEventListener(eventName, onClick, { target: document });
}