1 files changed, 53 insertions, 0 deletions
diff --git a/js/src/tests/non262/AsyncIterator/prototype/lazy-methods-iterator-closed-on-yield-throws.js b/js/src/tests/non262/AsyncIterator/prototype/lazy-methods-iterator-closed-on-yield-throws.js
new file mode 100644
index 0000000000..bec857eb33
--- /dev/null
+++ b/js/src/tests/non262/AsyncIterator/prototype/lazy-methods-iterator-closed-on-yield-throws.js
@@ -0,0 +1,53 @@
+// |reftest| skip-if(!this.hasOwnProperty('AsyncIterator'))
+
+//
+//
+/*---
+esid: pending
+description: Lazy %AsyncIterator.prototype% methods close the iterator if `yield` throws.
+info: >
+  AsyncIterator Helpers proposal 2.1.6
+features: [iterator-helpers]
+---*/
+
+class TestError extends Error {}
+class TestAsyncIterator extends AsyncIterator {
+  async next() { 
+    return {done: false, value: 1};
+  }
+
+  closed = false;
+  async return(value) {
+    this.closed = true;
+    return {done: true, value};
+  }
+}
+
+async function* gen(x) { yield x; }
+const methods = [
+  iter => iter.map(x => x),
+  iter => iter.filter(x => true),
+  iter => iter.take(1),
+  iter => iter.drop(0),
+  iter => iter.asIndexedPairs(),
+  iter => iter.flatMap(gen),
+];
+
+for (const method of methods) {
+  const iterator = new TestAsyncIterator();
+  const iteratorHelper = method(iterator);
+
+  assertEq(iterator.closed, false);
+  iteratorHelper.next().then(
+    _ => iteratorHelper.throw(new TestError()).then(
+      _ => assertEq(true, false, 'Expected reject'),
+      err => {
+        assertEq(err instanceof TestError, true);
+        assertEq(iterator.closed, true);
+      },
+    ),
+  );
+}
+
+if (typeof reportCompare == 'function')
+  reportCompare(0, 0);