Add Object.seal test

test/built-ins/Object/seal/proxy-with-defineProperty-handler.js

@@ -0,0 +1,41 @@
+// Copyright (C) 2021 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.seal
+description: >
+  [[DefineOwnProperty]] is called with partial descriptor with only [[Configurable]] field present.
+info: |
+  SetIntegrityLevel ( O, level )
+
+  [...]
+  5. Let keys be ? O.[[OwnPropertyKeys]]().
+  6. If level is sealed, then
+    a. For each element k of keys, do
+      i. Perform ? DefinePropertyOrThrow(O, k, PropertyDescriptor { [[Configurable]]: false }).
+features: [Symbol, Proxy, Reflect]
+---*/
+
+var sym = Symbol();
+var seenDescriptors = {};
+var proxy = new Proxy({
+  [sym]: 1,
+  get foo() {},
+  set foo(_v) {},
+}, {
+  defineProperty: function(target, key, descriptor) {
+    seenDescriptors[key] = descriptor;
+    return Reflect.defineProperty(target, key, descriptor);
+  },
+});
+
+Object.seal(proxy);
+
+assert.sameValue(seenDescriptors[sym].value, undefined, "value");
+assert.sameValue(seenDescriptors[sym].writable, undefined, "writable");
+assert.sameValue(seenDescriptors[sym].enumerable, undefined, "enumerable");
+assert.sameValue(seenDescriptors[sym].configurable, false, "configurable");
+
+assert.sameValue(seenDescriptors.foo.get, undefined, "get");
+assert.sameValue(seenDescriptors.foo.set, undefined, "set");
+assert.sameValue(seenDescriptors.foo.enumerable, undefined, "enumerable");
+assert.sameValue(seenDescriptors.foo.configurable, false, "configurable");