feat(asyncEmptyOnce): add asyncEmptyOnce function

Author: djcsdy

index.test.ts

@@ -1,6 +1,7 @@
 import type {ExecutionContext} from "ava";
 import test from "ava";
 import {
+    asyncEmptyOnce,
     asyncInitialOnce,
     asyncIterator,
     asyncLastOnce,
@@ -132,3 +133,9 @@ test("asyncOnlyOnce", async t => {
     t.is(await asyncOnlyOnce(asyncIterator([4])), 4);
     t.is(await asyncOnlyOnce(asyncIterator([3, 4, 5])), null);
 });
+
+test("asyncEmptyOnce", async t => {
+    t.is(await asyncEmptyOnce(asyncIterator([])), true);
+    t.is(await asyncEmptyOnce(asyncIterator([1])), false);
+    t.is(await asyncEmptyOnce(asyncIterator([1, 2, 3])), false);
+});

index.ts

@@ -186,3 +186,7 @@ export async function asyncOnlyOnce<T>(iterator: AsyncIteratorLike<T>): Promise<
         return null;
     }
 }
+
+export async function asyncEmptyOnce<T>(iterator: AsyncIteratorLike<T>): Promise<boolean> {
+    return (await asyncIterator(iterator).next()).done === true;
+}