vant/packages/vant-cli/site/common/index.js

function iframeReady(iframe, callback) {
  const doc = iframe.contentDocument || iframe.contentWindow.document;
  const interval = () => {
    if (iframe.contentWindow.replacePath) {
      callback();
    } else {
      setTimeout(interval, 50);
    }
  };

  if (doc.readyState === 'complete') {
    interval();
  } else {
    iframe.onload = interval;
  }
}

const ua = navigator.userAgent.toLowerCase();
const isMobile = /ios|iphone|ipod|ipad|android/.test(ua);

export function decamelize(str, sep = '-') {
  return str
    .replace(/([a-z\d])([A-Z])/g, '$1' + sep + '$2')
    .replace(/([A-Z]+)([A-Z][a-z\d]+)/g, '$1' + sep + '$2')
    .toLowerCase();
}

export { isMobile, iframeReady };