feat(utils): sleep fn

libs/util-fn/src/index.ts

@@ -16,3 +16,4 @@ export * from './pick';
 export * from './omit';
 export * from './magic';
 export * from './approx-eq';
+export * from './sleep';

libs/util-fn/src/sleep.spec.ts

@@ -0,0 +1,24 @@
+import { sleep } from './sleep';
+
+describe('sleep', () => {
+  it('resolves after the specified duration', async () => {
+    const start = Date.now();
+    await sleep(100);
+    const end = Date.now();
+    expect(end - start).toBeGreaterThanOrEqual(100);
+  });
+
+  it('resolves after a long duration', async () => {
+    const start = Date.now();
+    await sleep(1000);
+    const end = Date.now();
+    expect(end - start).toBeGreaterThanOrEqual(1000);
+  });
+
+  it('handles negative duration by resolving immediately', async () => {
+    const start = Date.now();
+    await sleep(-100);
+    const end = Date.now();
+    expect(end - start).toBeLessThan(10);
+  });
+});

libs/util-fn/src/sleep.ts

@@ -0,0 +1,7 @@
+export function sleep(duration: number): Promise<void> {
+  if (duration < 0) {
+    return Promise.resolve();
+  }
+
+  return new Promise((resolve) => setTimeout(resolve, duration));
+}