[runtime] PreventExtensionsWithTransition: before adding the new

test/mjsunit/regress/regress-refreeze-same-map.js

+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+// precondition
+assertTrue(%HaveSameMap(Object.freeze({}),     Object.freeze({})));
+assertTrue(%HaveSameMap(Object.freeze({a: 1}), Object.freeze({a: 1})));
+assertTrue(%HaveSameMap(Object.freeze([]),     Object.freeze([])));
+assertTrue(%HaveSameMap(Object.freeze([1,2]),  Object.freeze([1,2])));
+
+assertTrue(%HaveSameMap(Object.seal({}),     Object.seal({})));
+assertTrue(%HaveSameMap(Object.seal({a: 1}), Object.seal({a: 1})));
+assertTrue(%HaveSameMap(Object.seal([]),     Object.seal([])));
+assertTrue(%HaveSameMap(Object.seal([1,2]),  Object.seal([1,2])));
+
+// refreezing an already frozen obj does not keep adding transitions
+assertTrue(%HaveSameMap(Object.freeze({}),     Object.freeze( Object.freeze({}) )));
+assertTrue(%HaveSameMap(Object.freeze({a: 1}), Object.freeze( Object.freeze({a: 1}) )));
+assertTrue(%HaveSameMap(Object.freeze([]),     Object.freeze( Object.freeze([]) )));
+assertTrue(%HaveSameMap(Object.freeze([1,2]),  Object.freeze( Object.freeze([1,2]) )));
+
+// resealing a sealed object is idempotent
+assertTrue(%HaveSameMap(Object.seal({}),     Object.seal( Object.seal({}) )));
+assertTrue(%HaveSameMap(Object.seal({a: 1}), Object.seal( Object.seal({a: 1}) )));
+assertTrue(%HaveSameMap(Object.seal([]),     Object.seal( Object.seal([]) )));
+assertTrue(%HaveSameMap(Object.seal([1,2]),  Object.seal( Object.seal([1,2]) )));
+
+// sealing a frozen object is idempotent
+assertTrue(%HaveSameMap(Object.freeze({}),     Object.seal( Object.freeze({}) )));
+assertTrue(%HaveSameMap(Object.freeze({a: 1}), Object.seal( Object.freeze({a: 1}) )));
+assertTrue(%HaveSameMap(Object.freeze([]),     Object.seal( Object.freeze([]) )));
+assertTrue(%HaveSameMap(Object.freeze([1,2]),  Object.seal( Object.freeze([1,2]) )));
+
+// freezing a sealed empty is idempotent
+assertTrue(%HaveSameMap(Object.freeze(Object.seal({})), Object.seal({})));
+
+// sealing a unextensible empty object is idempotent
+assertTrue(%HaveSameMap(Object.seal(Object.preventExtensions({})), Object.preventExtensions({})));