/**
 * Shallow equality check for selector results.
 * Uses Object.is for value comparison (handles NaN and +-0 correctly).
 */
export function shallowEqual<T>(a: T, b: T): boolean {
  if (Object.is(a, b)) return true;
  if (
    typeof a !== "object" ||
    a === null ||
    typeof b !== "object" ||
    b === null
  ) {
    return false;
  }
  const keysA = Object.keys(a);
  const keysB = Object.keys(b);
  if (keysA.length !== keysB.length) return false;
  for (const key of keysA) {
    if (
      !Object.hasOwn(b, key) ||
      !Object.is((a as any)[key], (b as any)[key])
    ) {
      return false;
    }
  }
  return true;
}