1 files changed, 59 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Proxy/defineProperty/trap-is-null-target-is-proxy.js b/js/src/tests/test262/built-ins/Proxy/defineProperty/trap-is-null-target-is-proxy.js
new file mode 100644
index 0000000000..0beb8e52a0
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Proxy/defineProperty/trap-is-null-target-is-proxy.js
@@ -0,0 +1,59 @@
+// 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: [propertyHelper.js]
+---*/
+
+var plainObject = Object.create(null);
+Object.defineProperty(plainObject, "foo", {
+  configurable: false,
+});
+
+var plainObjectTarget = new Proxy(plainObject, {});
+var plainObjectProxy = new Proxy(plainObjectTarget, {
+  defineProperty: null,
+});
+
+assert.throws(TypeError, function() {
+  Object.defineProperty(plainObjectProxy, "foo", {
+    configurable: true,
+  });
+});
+
+Object.defineProperty(plainObjectProxy, "bar", {
+  get: function() {
+    return 2;
+  },
+});
+assert.sameValue(plainObject.bar, 2);
+
+
+var regExp = /(?:)/g;
+var regExpTarget = new Proxy(regExp, {});
+var regExpProxy = new Proxy(regExpTarget, {
+  defineProperty: null,
+});
+
+assert(
+  Reflect.defineProperty(regExpProxy, "lastIndex", {
+    writable: false,
+  })
+);
+
+verifyNotWritable(regExp, "lastIndex");
+
+reportCompare(0, 0);