1 files changed, 43 insertions, 0 deletions
diff --git a/js/src/tests/non262/Iterator/prototype/map/values-pass-through-chained-maps-to-next.js b/js/src/tests/non262/Iterator/prototype/map/values-pass-through-chained-maps-to-next.js
new file mode 100644
index 0000000000..d49daebb87
--- /dev/null
+++ b/js/src/tests/non262/Iterator/prototype/map/values-pass-through-chained-maps-to-next.js
@@ -0,0 +1,43 @@
+// |reftest| skip-if(!this.hasOwnProperty('Iterator'))
+//
+
+/*---
+esid: pending
+description: Multiple chained %Iterator.prototype%.map calls pass `lastValue` to the iterator's `next` call.
+info: >
+  Iterator Helpers Proposal 2.1.5.2
+features: [iterator-helpers]
+---*/
+
+let nextWasPassed;
+
+const iteratorWhereNextTakesValue = Object.setPrototypeOf({
+  next: function(value) {
+    nextWasPassed = value;
+
+    if (this.value < 3)
+      return { done: false, value: this.value++ };
+    return { done: true, value: undefined };
+  },
+  value: 0,
+}, Iterator.prototype);
+
+const mappedIterator = iteratorWhereNextTakesValue.map(x => 2 * x).map(x => 1 + x);
+
+assertEq(mappedIterator.next(1).value, 1);
+assertEq(nextWasPassed, undefined);
+
+assertEq(mappedIterator.next(2).value, 3);
+assertEq(nextWasPassed, 2);
+
+assertEq(mappedIterator.next(3).value, 5);
+assertEq(nextWasPassed, 3);
+
+assertEq(mappedIterator.next(4).done, true);
+assertEq(nextWasPassed, 4);
+
+assertEq(mappedIterator.next(5).done, true);
+assertEq(nextWasPassed, 4);
+
+if (typeof reportCompare == 'function')
+  reportCompare(0, 0);