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-rw-r--r--js/src/tests/non262/destructuring/rest-parameter-aray-iterator.js40
1 files changed, 40 insertions, 0 deletions
diff --git a/js/src/tests/non262/destructuring/rest-parameter-aray-iterator.js b/js/src/tests/non262/destructuring/rest-parameter-aray-iterator.js
new file mode 100644
index 0000000000..bf9643fd78
--- /dev/null
+++ b/js/src/tests/non262/destructuring/rest-parameter-aray-iterator.js
@@ -0,0 +1,40 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Destructuring rest arrays call the array iterator. This behaviour is
+// observable when Array.prototype[Symbol.iterator] is overridden.
+
+const oldArrayIterator = Array.prototype[Symbol.iterator];
+try {
+ let callCount = 0;
+ Array.prototype[Symbol.iterator] = function() {
+ callCount += 1;
+ return oldArrayIterator.call(this);
+ };
+
+ // Array iterator called exactly once.
+ function arrayIterCalledOnce(...[]) { }
+ assertEq(callCount, 0);
+ arrayIterCalledOnce();
+ assertEq(callCount, 1);
+
+ // Array iterator not called before rest parameter.
+ callCount = 0;
+ function arrayIterNotCalledBeforeRest(t = assertEq(callCount, 0), ...[]) { }
+ assertEq(callCount, 0);
+ arrayIterNotCalledBeforeRest();
+ assertEq(callCount, 1);
+
+ // Array iterator called when rest parameter is processed.
+ callCount = 0;
+ function arrayIterCalledWhenDestructuring(...[t = assertEq(callCount, 1)]) { }
+ assertEq(callCount, 0);
+ arrayIterCalledWhenDestructuring();
+ assertEq(callCount, 1);
+} finally {
+ Array.prototype[Symbol.iterator] = oldArrayIterator;
+}
+
+if (typeof reportCompare === "function")
+ reportCompare(0, 0);