Add Reflect.ownKeys test

test/built-ins/Reflect/ownKeys/order-after-define-property.js

@@ -0,0 +1,50 @@
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-reflect.ownkeys
+description: >
+  Property names are returned in ascending chronological order of creation
+  that is unaffected by [[DefineOwnProperty]].
+info: |
+  Reflect.ownKeys ( target )
+
+  [...]
+  2. Let keys be ? target.[[OwnPropertyKeys]]().
+  3. Return CreateArrayFromList(keys).
+
+  OrdinaryOwnPropertyKeys ( O )
+
+  [...]
+  4. For each own property key P of O that is a Symbol, in ascending
+  chronological order of property creation, do
+    a. Add P as the last element of keys.
+  5. Return keys.
+
+  [[OwnPropertyKeys]] ( )
+
+  [...]
+  7. For each own property key P of O such that Type(P) is String and P is not
+  an array index, in ascending chronological order of property creation, do
+    a. Add P as the last element of keys.
+  [...]
+  9. Return keys.
+features: [Symbol, Reflect]
+includes: [compareArray.js]
+---*/
+
+var obj = {};
+var symA = Symbol("a");
+var symB = Symbol("b");
+obj[symA] = 1;
+obj[symB] = 2;
+Object.defineProperty(obj, symA, {configurable: false});
+assert.compareArray(Reflect.ownKeys(obj), [symA, symB]);
+
+var str = new String("");
+str.a = 1;
+str.b = 2;
+Object.defineProperty(str, "a", {
+  get: function() {},
+});
+assert.compareArray(Reflect.ownKeys(str), ["length", "a", "b"]);