1 files changed, 45 insertions, 0 deletions
diff --git a/js/src/tests/non262/Iterator/prototype/lazy-methods-iterator-closed-on-yield-throws.js b/js/src/tests/non262/Iterator/prototype/lazy-methods-iterator-closed-on-yield-throws.js
new file mode 100644
index 0000000000..361b800404
--- /dev/null
+++ b/js/src/tests/non262/Iterator/prototype/lazy-methods-iterator-closed-on-yield-throws.js
@@ -0,0 +1,45 @@
+// |reftest| skip-if(!this.hasOwnProperty('Iterator'))
+
+//
+//
+/*---
+esid: pending
+description: Lazy %Iterator.prototype% methods close the iterator if `yield` throws.
+info: >
+  Iterator Helpers proposal 2.1.5
+features: [iterator-helpers]
+---*/
+
+class TestError extends Error {}
+class TestIterator extends Iterator {
+  next() { 
+    return {done: false, value: 1};
+  }
+
+  closed = false;
+  return() {
+    this.closed = true;
+    return {done: true};
+  }
+}
+
+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(x => [x]),
+];
+
+for (const method of methods) {
+  const iterator = new TestIterator();
+  assertEq(iterator.closed, false);
+  const iteratorHelper = method(iterator);
+  iteratorHelper.next();
+  assertThrowsInstanceOf(() => iteratorHelper.throw(new TestError()), TestError);
+  assertEq(iterator.closed, true); 
+}
+
+if (typeof reportCompare == 'function')
+  reportCompare(0, 0);