1 files changed, 42 insertions, 0 deletions
diff --git a/js/src/tests/non262/AsyncIterator/prototype/lazy-methods-handle-empty-iterators.js b/js/src/tests/non262/AsyncIterator/prototype/lazy-methods-handle-empty-iterators.js
new file mode 100644
index 0000000000..b1bd426dd8
--- /dev/null
+++ b/js/src/tests/non262/AsyncIterator/prototype/lazy-methods-handle-empty-iterators.js
@@ -0,0 +1,42 @@
+// |reftest| skip-if(!this.hasOwnProperty('AsyncIterator'))
+
+//
+//
+/*---
+esid: pending
+description: Lazy %AsyncIterator.prototype% methods handle empty iterators.
+info: >
+  Iterator Helpers proposal 2.1.6
+features: [iterator-helpers]
+---*/
+
+class EmptyIterator extends AsyncIterator {
+  async next() { 
+    return {done: true};
+  }
+}
+
+async function* gen() {}
+
+const methods = [
+  iter => iter.map(x => x),
+  iter => iter.filter(x => x),
+  iter => iter.take(1),
+  iter => iter.drop(0),
+  iter => iter.asIndexedPairs(),
+  iter => iter.flatMap(x => gen()),
+];
+
+for (const method of methods) {
+  for (const iterator of [new EmptyIterator(), gen()]) {
+    method(iterator).next().then(
+      ({done, value}) => {
+        assertEq(done, true);
+        assertEq(value, undefined);
+      }
+    );
+  }
+}
+
+if (typeof reportCompare == 'function')
+  reportCompare(0, 0);