Function optionsToId

src/observe.ts:44–58

(options: IntersectionObserverInit)

 * @param options
 */
export function optionsToId(options: IntersectionObserverInit) {
  return Object.keys(options)
    .sort()
    .filter(
      (key) => options[key as keyof IntersectionObserverInit] !== undefined,
    )
    .map((key) => {
      return `${key}_${
        key === "root"
          ? getRootId(options.root)
          : options[key as keyof IntersectionObserverInit]
      }`;
    })
    .toString();
}

function createObserver(options: IntersectionObserverInit) {
  // Create a unique ID for this observer instance, based on the root, root margin and threshold.