1 files changed, 42 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Array/prototype/with/length-decreased-while-iterating.js b/js/src/tests/test262/built-ins/Array/prototype/with/length-decreased-while-iterating.js
new file mode 100644
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+++ b/js/src/tests/test262/built-ins/Array/prototype/with/length-decreased-while-iterating.js
@@ -0,0 +1,42 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-array.prototype.with
+description: >
+  Array.prototype.with caches the length getting the array elements.
+info: |
+  Array.prototype.with ( index, value )
+
+  ...
+  2. Let len be ? LengthOfArrayLike(O).
+  ...
+  5. Repeat, while k < len
+    a. Let Pk be ! ToString(𝔽(k)).
+    b. If k is actualIndex, let fromValue be value.
+    c. Else, let fromValue be ? Get(O, Pk).
+    d. Perform ? CreateDataPropertyOrThrow(A, Pk, fromValue).
+    e. Set k to k + 1.
+features: [change-array-by-copy]
+includes: [compareArray.js]
+---*/
+
+Array.prototype[4] = 5;
+
+var arr = Object.defineProperty([0, 1, 2, 3, 4], "1", {
+  get() {
+    arr.length = 1;
+    return 1;
+  }
+});
+assert.compareArray(arr.with(2, 7), [0, 1, 7, undefined, 5]);
+
+arr = Object.defineProperty([0, 1, 2, 3, 4], "1", {
+  get() {
+    arr.length = 1;
+    return 1;
+  }
+});
+assert.compareArray(arr.with(0, 7), [7, 1, undefined, undefined, 5]);
+
+reportCompare(0, 0);