1 files changed, 7 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/proxy/testDirectProxyKeys4.js b/js/src/jit-test/tests/proxy/testDirectProxyKeys4.js
new file mode 100644
index 0000000000..16ce41a029
--- /dev/null
+++ b/js/src/jit-test/tests/proxy/testDirectProxyKeys4.js
@@ -0,0 +1,7 @@
+load(libdir + "asserts.js");
+
+// Throw TypeError if trap returns a property key multiple times.
+
+var handler = { ownKeys: () => [ 'foo', 'foo' ] };
+for (let p of [new Proxy({}, handler), Proxy.revocable({}, handler).proxy])
+    assertThrowsInstanceOf(() => Object.keys(p), TypeError);