1 files changed, 30 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/TypedArray/prototype/at/returns-undefined-for-out-of-range-index.js b/js/src/tests/test262/built-ins/TypedArray/prototype/at/returns-undefined-for-out-of-range-index.js
new file mode 100644
index 0000000000..8a954e3971
--- /dev/null
+++ b/js/src/tests/test262/built-ins/TypedArray/prototype/at/returns-undefined-for-out-of-range-index.js
@@ -0,0 +1,30 @@
+// Copyright (C) 2020 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-%typedarray%.prototype.at
+description: >
+  Returns undefined if the specified index less than or greater than the available index range.
+info: |
+  %TypedArray%.prototype.at( index )
+
+  If k < 0 or k ≥ len, then return undefined.
+
+includes: [testTypedArray.js]
+features: [TypedArray,TypedArray.prototype.at]
+---*/
+assert.sameValue(
+  typeof TypedArray.prototype.at,
+  'function',
+  'The value of `typeof TypedArray.prototype.at` is "function"'
+);
+
+testWithTypedArrayConstructors(TA => {
+  assert.sameValue(typeof TA.prototype.at, 'function', 'The value of `typeof TA.prototype.at` is "function"');
+  let a = new TA([]);
+
+  assert.sameValue(a.at(-2), undefined, 'a.at(-2) must return undefined'); // wrap around the end
+  assert.sameValue(a.at(0), undefined, 'a.at(0) must return undefined');
+  assert.sameValue(a.at(1), undefined, 'a.at(1) must return undefined');
+});
+
+reportCompare(0, 0);