1 files changed, 26 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Proxy/ownKeys/return-duplicate-symbol-entries-throws.js b/js/src/tests/test262/built-ins/Proxy/ownKeys/return-duplicate-symbol-entries-throws.js
new file mode 100644
index 0000000000..09d2697890
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Proxy/ownKeys/return-duplicate-symbol-entries-throws.js
@@ -0,0 +1,26 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-proxy-object-internal-methods-and-internal-slots-ownpropertykeys
+description: >
+    The returned list must not contain any duplicate entries.
+info: |
+    [[OwnPropertyKeys]] ( )
+
+    ...
+    9. If trapResult contains any duplicate entries, throw a TypeError exception.
+features: [Proxy, Symbol]
+---*/
+
+var s = Symbol();
+var p = new Proxy({}, {
+  ownKeys: function() {
+    return [s, s];
+  }
+});
+
+assert.throws(TypeError, function() {
+  Object.keys(p);
+});
+
+reportCompare(0, 0);