1 files changed, 33 insertions, 0 deletions
diff --git a/js/src/tests/non262/Proxy/ownkeys-trap-duplicates.js b/js/src/tests/non262/Proxy/ownkeys-trap-duplicates.js
new file mode 100644
index 0000000000..d525662657
--- /dev/null
+++ b/js/src/tests/non262/Proxy/ownkeys-trap-duplicates.js
@@ -0,0 +1,33 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+var gTestfile = 'ownkeys-trap-duplicates.js';
+var BUGNUMBER = 1293995;
+var summary =
+  "Scripted proxies' [[OwnPropertyKeys]] should not throw if the trap " +
+  "implementation returns duplicate properties and the object is " +
+  "non-extensible or has non-configurable properties." +
+  "Revised (bug 1389752): Throw TypeError for duplicate properties.";
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+var target = Object.preventExtensions({ a: 1 });
+var proxy = new Proxy(target, { ownKeys(t) { return ["a", "a"]; } });
+assertThrowsInstanceOf(() => Object.getOwnPropertyNames(proxy), TypeError);
+
+target = Object.freeze({ a: 1 });
+proxy = new Proxy(target, { ownKeys(t) { return ["a", "a"]; } });
+assertThrowsInstanceOf(() => Object.getOwnPropertyNames(proxy), TypeError);
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");