1 files changed, 57 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Proxy/defineProperty/trap-is-undefined-target-is-proxy.js b/js/src/tests/test262/built-ins/Proxy/defineProperty/trap-is-undefined-target-is-proxy.js
new file mode 100644
index 0000000000..26934ca15f
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Proxy/defineProperty/trap-is-undefined-target-is-proxy.js
@@ -0,0 +1,57 @@
+// Copyright (C) 2020 Alexey Shvayka. 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-defineownproperty-p-desc
+description: >
+  If "defineProperty" trap is null or undefined, [[DefineOwnProperty]] call
+  is properly forwarded to [[ProxyTarget]] (which is also a Proxy object).
+info: |
+  [[DefineOwnProperty]] (P, Desc)
+
+  [...]
+  5. Let target be O.[[ProxyTarget]].
+  6. Let trap be ? GetMethod(handler, "defineProperty").
+  7. If trap is undefined, then
+    a. Return ? target.[[DefineOwnProperty]](P, Desc).
+features: [Proxy, Reflect]
+includes: [compareArray.js]
+---*/
+
+var array = [];
+var arrayTarget = new Proxy(array, {});
+var arrayProxy = new Proxy(arrayTarget, {
+  defineProperty: undefined,
+});
+
+Object.defineProperty(arrayProxy, "0", {value: 1});
+assert.compareArray(array, [1]);
+
+assert.throws(TypeError, function() {
+  Object.defineProperty(arrayProxy, "length", {
+    get: function() {},
+  });
+});
+
+
+var trapCalls = 0;
+var target = new Proxy({}, {
+  defineProperty: function(_target, key) {
+    trapCalls++;
+    return key === "foo";
+  },
+});
+
+var proxy = new Proxy(target, {
+  defineProperty: undefined,
+});
+
+assert(Reflect.defineProperty(proxy, "foo", {}));
+assert.sameValue(trapCalls, 1);
+
+assert.throws(TypeError, function() {
+  Object.defineProperty(proxy, "bar", {});
+});
+assert.sameValue(trapCalls, 2);
+
+reportCompare(0, 0);