Implement Object.getOwnPropertyDescriptors built-in method (#3921)

JerryScript-DCO-1.0-Signed-off-by: Roland Takacs rtakacs@inf.u-szeged.hu

tests/jerry/es.next/object-get-own-property-descriptors.js

@@ -0,0 +1,119 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+var object = {};
+var symbol = Symbol("symbol");
+
+function getter() { return 2; }
+function setter(value) {}
+
+// Append a symbol property.
+object[symbol] = "symbol";
+
+Object.defineProperties(object, {
+  "foo" : {
+    get: getter,
+    set: setter,
+    enumerable: true,
+    configurable: true,
+  },
+  "bar": {
+    value: "bar",
+    writable: true,
+    enumerable: false,
+    configurable: true,
+  },
+  "baz": {
+    value: undefined,
+    writable: false,
+    enumerable: true,
+    configurable: false,
+  },
+});
+
+var descriptors = Object.getOwnPropertyDescriptors(object);
+
+// All the descriptor keys should be enumerable.
+var keys = Object.keys(descriptors);
+var names = Object.getOwnPropertyNames(descriptors);
+var symbols = Object.getOwnPropertySymbols(descriptors);
+
+assert(keys.length === names.length);
+assert(symbols.length === 1);
+
+for (var idx = 0; idx < keys.length; idx++) {
+  assert(keys[idx] === names[idx]);
+}
+
+assert(descriptors[symbol].value === "symbol");
+
+assert(descriptors["foo"].get === getter);
+assert(descriptors["foo"].set === setter);
+assert(descriptors["foo"].enumerable === true);
+assert(descriptors["foo"].configurable === true);
+
+assert(descriptors["bar"].value === "bar");
+assert(descriptors["bar"].writable === true);
+assert(descriptors["bar"].enumerable === false);
+assert(descriptors["bar"].configurable === true);
+
+assert(descriptors["baz"].value === undefined);
+assert(descriptors["baz"].writable === false);
+assert(descriptors["baz"].enumerable === true);
+assert(descriptors["baz"].configurable === false);
+
+// Compare getOwnPropertyDescriptor and getOwnPropertyDescriptors.
+for (let i of Object.getOwnPropertyNames(object)) {
+  let lhs = JSON.stringify(Object.getOwnPropertyDescriptor(object, i));
+  let rhs = JSON.stringify(descriptors[i]);
+
+  assert(lhs === rhs);
+}
+
+var array_desc = Object.getOwnPropertyDescriptors(Array);
+assert(array_desc.prototype.value === Array.prototype);
+assert(array_desc.prototype.writable === false);
+assert(array_desc.prototype.configurable === false);
+assert(array_desc.prototype.enumerable === false);
+
+try {
+  Object.getOwnPropertyDescriptors(undefined);
+  assert(false);
+} catch(e) {
+  assert(e instanceof TypeError);
+}
+
+var proxy_get_desc_handler = new Proxy(object, {
+  getOwnPropertyDescriptor(target, prop) {
+    throw new Error("Error");
+  }
+});
+
+var proxy_own_keys_handler = new Proxy(object, {
+  ownKeys: 42,
+});
+
+try {
+  Object.getOwnPropertyDescriptors(proxy_get_desc_handler);
+  assert(false);
+} catch(e) {
+  assert(e instanceof Error);
+}
+
+try {
+  Object.getOwnPropertyDescriptors(proxy_own_keys_handler);
+  assert(false);
+} catch(e) {
+  assert(e instanceof TypeError);
+}