1 files changed, 41 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/TypedArray/prototype/findLast/predicate-may-detach-buffer.js b/js/src/tests/test262/built-ins/TypedArray/prototype/findLast/predicate-may-detach-buffer.js
new file mode 100644
index 0000000000..51cc7dad9a
--- /dev/null
+++ b/js/src/tests/test262/built-ins/TypedArray/prototype/findLast/predicate-may-detach-buffer.js
@@ -0,0 +1,41 @@
+// Copyright (C) 2021 Microsoft. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-%typedarray%.prototype.findlast
+description: >
+  Predicate may detach the buffer
+info: |
+  %TypedArray%.prototype.findLast (predicate [ , thisArg ] )
+
+  ...
+
+  However, such optimization must not introduce any observable changes in the
+  specified behaviour of the algorithm and must take into account the
+  possibility that calls to predicate may cause the this value to become
+  detached.
+
+  IntegerIndexedElementGet ( O, index )
+
+    ...
+    Let buffer be the value of O's [[ViewedArrayBuffer]] internal slot.
+    If IsDetachedBuffer(buffer) is true, return undefined.
+
+includes: [testTypedArray.js, detachArrayBuffer.js]
+features: [TypedArray, array-find-from-last]
+---*/
+
+testWithTypedArrayConstructors(function(TA) {
+  var loops = 0;
+  var sample = new TA(2);
+
+  sample.findLast(function() {
+    if (loops === 0) {
+      $DETACHBUFFER(sample.buffer);
+    }
+    loops++;
+  });
+
+  assert.sameValue(loops, 2);
+});
+
+reportCompare(0, 0);