1 files changed, 48 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Array/length/define-own-prop-length-coercion-order-set.js b/js/src/tests/test262/built-ins/Array/length/define-own-prop-length-coercion-order-set.js
new file mode 100644
index 0000000000..bb3acea2e2
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Array/length/define-own-prop-length-coercion-order-set.js
@@ -0,0 +1,48 @@
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: André Bargull
+esid: sec-arraysetlength
+description: >
+  [[Value]] is coerced to number before current descriptor's [[Writable]] check.
+info: |
+  ArraySetLength ( A, Desc )
+
+  [...]
+  3. Let newLen be ? ToUint32(Desc.[[Value]]).
+  4. Let numberLen be ? ToNumber(Desc.[[Value]]).
+  [...]
+  7. Let oldLenDesc be OrdinaryGetOwnProperty(A, "length").
+  [...]
+  12. If oldLenDesc.[[Writable]] is false, return false.
+features: [Symbol, Symbol.toPrimitive, Reflect, Reflect.set]
+includes: [compareArray.js]
+---*/
+
+var array = [1, 2, 3];
+var hints = [];
+var length = {};
+length[Symbol.toPrimitive] = function(hint) {
+  hints.push(hint);
+  Object.defineProperty(array, "length", {writable: false});
+  return 0;
+};
+
+assert.throws(TypeError, function() {
+  "use strict";
+  array.length = length;
+}, '`"use strict"; array.length = length` throws a TypeError exception');
+assert.compareArray(hints, ["number", "number"], 'The value of hints is expected to be ["number", "number"]');
+
+
+array = [1, 2, 3];
+hints = [];
+
+assert(
+  !Reflect.set(array, "length", length),
+  'The value of !Reflect.set(array, "length", length) is expected to be true'
+);
+assert.compareArray(hints, ["number", "number"], 'The value of hints is expected to be ["number", "number"]');
+
+reportCompare(0, 0);