Function wrapEqualityFn

packages/core/src/resource/resource.ts:541–543

* Wraps an equality function to handle either value being `undefined`.

(equal: ValueEqualityFn<T>)

 * Wraps an equality function to handle either value being `undefined`.
 */
function wrapEqualityFn<T>(equal: ValueEqualityFn<T>): ValueEqualityFn<T | undefined> {
  return (a, b) => (a === undefined || b === undefined ? a === b : equal(a, b));
}

function getLoader<T, R>(options: ResourceOptions<T, R>): ResourceStreamingLoader<T, R> {
  if (isStreamingResourceOptions(options)) {