1 files changed, 31 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Object/prototype/isPrototypeOf/arg-is-proxy.js b/js/src/tests/test262/built-ins/Object/prototype/isPrototypeOf/arg-is-proxy.js
new file mode 100644
index 0000000000..88717f0e54
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/prototype/isPrototypeOf/arg-is-proxy.js
@@ -0,0 +1,31 @@
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-object.prototype.isprototypeof
+description: >
+  If V is a Proxy object, only its "getPrototypeOf" trap gets invoked.
+info: |
+  Object.prototype.isPrototypeOf ( V )
+
+  ...
+  3. Repeat,
+    a. Set V to ? V.[[GetPrototypeOf]]().
+    b. If V is null, return false.
+    c. If SameValue(O, V) is true, return true.
+includes: [proxyTrapsHelper.js]
+features: [Proxy]
+---*/
+
+var proxyProto = [];
+var handler = allowProxyTraps({
+  getPrototypeOf: function(_target) {
+    return proxyProto;
+  },
+});
+
+var proxy = new Proxy({}, handler);
+
+assert.sameValue(proxyProto.isPrototypeOf(proxy), true);
+
+reportCompare(0, 0);