swiper/shared/get-support.js

import { getWindow, getDocument } from 'ssr-window';
let support;

function calcSupport() {
  const window = getWindow();
  const document = getDocument();
  return {
    smoothScroll: document.documentElement && 'scrollBehavior' in document.documentElement.style,
    touch: !!('ontouchstart' in window || window.DocumentTouch && document instanceof window.DocumentTouch),
    passiveListener: function checkPassiveListener() {
      let supportsPassive = false;

      try {
        const opts = Object.defineProperty({}, 'passive', {
          // eslint-disable-next-line
          get() {
            supportsPassive = true;
          }

        });
        window.addEventListener('testPassiveListener', null, opts);
      } catch (e) {// No support
      }

      return supportsPassive;
    }(),
    gestures: function checkGestures() {
      return 'ongesturestart' in window;
    }()
  };
}

function getSupport() {
  if (!support) {
    support = calcSupport();
  }

  return support;
}

export { getSupport };