Function intersectionMockInstance

src/test-utils.ts:277–290

(
  element: Element,
)

 * @return IntersectionObserver
 */
export function intersectionMockInstance(
  element: Element,
): IntersectionObserver {
  warnOnMissingSetup();
  for (const [observer, item] of observers) {
    if (item.elements.has(element)) {
      return observer;
    }
  }

  throw new Error(
    "Failed to find IntersectionObserver for element. Is it being observed?",
  );
}