1 files changed, 51 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/TypedArray/prototype/reduce/callbackfn-set-value-during-iteration.js b/js/src/tests/test262/built-ins/TypedArray/prototype/reduce/callbackfn-set-value-during-iteration.js
new file mode 100644
index 0000000000..8fd43bad16
--- /dev/null
+++ b/js/src/tests/test262/built-ins/TypedArray/prototype/reduce/callbackfn-set-value-during-iteration.js
@@ -0,0 +1,51 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-%typedarray%.prototype.reduce
+description: >
+  Integer indexed values changed during iteration
+info: |
+  22.2.3.20 %TypedArray%.prototype.reduce ( callbackfn [ , initialValue ] )
+
+  %TypedArray%.prototype.reduce is a distinct function that implements the same
+  algorithm as Array.prototype.reduce as defined in 22.1.3.19 except that the
+  this object's [[ArrayLength]] internal slot is accessed in place of performing
+  a [[Get]] of "length".
+
+  22.1.3.19 Array.prototype.reduce ( callbackfn [ , initialValue ] )
+includes: [testTypedArray.js]
+features: [Reflect.set, TypedArray]
+---*/
+
+testWithTypedArrayConstructors(function(TA) {
+  var sample = new TA([42, 43, 44]);
+  var newVal = 0;
+
+  sample.reduce(function(acc, val, i) {
+    if (i > 0) {
+      assert.sameValue(
+        sample[i - 1], newVal - 1,
+        "get the changed value during the loop"
+      );
+      assert.sameValue(
+        Reflect.set(sample, 0, 7),
+        true,
+        "re-set a value for sample[0]"
+      );
+    }
+    assert.sameValue(
+      Reflect.set(sample, i, newVal),
+      true,
+      "set value during iteration"
+    );
+
+    newVal++;
+  }, 0);
+
+  assert.sameValue(sample[0], 7, "changed values after iteration [0] == 7");
+  assert.sameValue(sample[1], 1, "changed values after iteration [1] == 1");
+  assert.sameValue(sample[2], 2, "changed values after iteration [2] == 2");
+});
+
+reportCompare(0, 0);