Function matchesObserver

testing/intersection-observer-stub.js:117–125

* @param {!IntersectionObserverStub} observer * @param {{ * root: (!Document|!Element|undefined), * rootMargin: (string|undefined), * thresholds: (number|!Array |undefined), * }} options

(observer, options)

 * }} options
 */
function matchesObserver(observer, options) {
  const {root, rootMargin, thresholds} = options;
  return (
    (root === undefined || root == observer.root) &&
    (rootMargin === undefined || rootMargin == observer.rootMargin) &&
    (thresholds === undefined ||
      areEqualOrdered(thresholds, observer.thresholds))
  );
}