@elibrary-inno/bookreader/src/util/browserSniffing.js

The Internet Archive BookReader.

/**
 * Checks whether the current browser is a Chrome/Chromium browser
 * Code from https://stackoverflow.com/a/4565120/2317712
 * @param {string} [userAgent]
 * @param {string} [vendor]
 * @return {boolean}
 */
export function isChrome(userAgent = navigator.userAgent, vendor = navigator.vendor) {
  return /chrome/i.test(userAgent) && /google inc/i.test(vendor);
}

/**
 * Checks whether the current browser is firefox
 * @param {string} [userAgent]
 * @return {boolean}
 */
export function isFirefox(userAgent = navigator.userAgent) {
  return /firefox/i.test(userAgent);
}

/**
 * Checks whether the current browser is safari
 * https://developer.mozilla.org/en-US/docs/Web/HTTP/Browser_detection_using_the_user_agent#Browser_Name
 * @param {string} [userAgent]
 * @return {boolean}
 */
export function isSafari(userAgent = navigator.userAgent) {
  return /safari/i.test(userAgent) && !/chrome|chromium/i.test(userAgent);
}

/**
 * Checks whether the current browser is iOS (and hence iOS webkit)
 * @return {boolean}
 */
export function isIOS() {
  // We can't just check the userAgent because as of iOS 13,
  // the userAgent is the same as desktop Safari because
  // they wanted iPad's to be served the same version of websites
  // as desktops.
  return 'ongesturestart' in window && navigator.maxTouchPoints > 0;
}

/**
 * Checks whether the current browser is Samsung Internet
 * https://stackoverflow.com/a/40684162/2317712
 * @param {string} [userAgent]
 * @return {boolean}
 */
export function isSamsungInternet(userAgent = navigator.userAgent) {
  return /SamsungBrowser/i.test(userAgent);
}