Function supportsPassive

src/js/utils/events.js:223–241

()

let _supportsPassive;

const supportsPassive = function() {
  if (typeof _supportsPassive !== 'boolean') {
    _supportsPassive = false;
    try {
      const opts = Object.defineProperty({}, 'passive', {
        get() {
          _supportsPassive = true;
        }
      });

      window.addEventListener('test', null, opts);
      window.removeEventListener('test', null, opts);
    } catch (e) {
      // disregard
    }
  }

  return _supportsPassive;
};

/**
 * Touch events Chrome expects to be passive