feat(util): until functions

core/util/src/index.ts

@@ -0,0 +1 @@
+export * from './until.js';

core/util/src/until.ts

@@ -0,0 +1,15 @@
+export function untilEvent(element: Element, eventName: string): Promise<Event> {
+  return new Promise((resolve) => element.addEventListener(eventName, resolve));
+}
+
+export function delay(duration: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, duration));
+}
+
+export function untilNextFrame(): Promise<DOMHighResTimeStamp> {
+  return new Promise((resolve) => requestAnimationFrame(resolve));
+}
+
+export function untilIdle(timeout?: number): Promise<IdleDeadline> {
+  return new Promise((resolve) => requestIdleCallback(resolve, {timeout}));
+}