userAgent check

by ShaCP

JavaScript

const isAndroidAndFirefox =
  (() => {
    let isAndroidAndFirefox;
    window.onload = () => {
      userAgent = navigator.userAgent
      const isAndroid = (/android/i).test(userAgent);
      const isFirefox = (/firefox/i).test(userAgent);
      isAndroidAndFirefox = isAndroid && isFirefox;
    }
    return () => isAndroidAndFirefox;
  })();