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/* Any copyright is dedicated to the Public Domain.
* http://creativecommons.org/licenses/publicdomain/ */
// Reflect.setPrototypeOf changes an object's [[Prototype]].
var obj = {};
assertEq(Object.getPrototypeOf(obj), Object.prototype);
var proto = {};
assertEq(Reflect.setPrototypeOf(obj, proto), true);
assertEq(Object.getPrototypeOf(obj), proto);
// It can change an object's [[Prototype]] to null.
obj = {};
assertEq(Reflect.setPrototypeOf(obj, null), true);
assertEq(Object.getPrototypeOf(obj), null);
// The proto argument is required too.
obj = {};
assertThrowsInstanceOf(() => Reflect.setPrototypeOf(obj), TypeError);
// The proto argument must be either null or an object.
for (proto of [undefined, false, 0, 1.6, "that", Symbol.iterator]) {
assertThrowsInstanceOf(() => Reflect.setPrototypeOf(obj, proto), TypeError);
}
// Return false if the target isn't extensible.
proto = {};
obj = Object.preventExtensions(Object.create(proto));
assertEq(Reflect.setPrototypeOf(obj, {}), false);
assertEq(Reflect.setPrototypeOf(obj, null), false);
assertEq(Reflect.setPrototypeOf(obj, proto), true); // except if not changing anything
// Return false rather than create a [[Prototype]] cycle.
obj = {};
assertEq(Reflect.setPrototypeOf(obj, obj), false);
// Don't create a [[Prototype]] cycle involving 2 objects.
obj = Object.create(proto);
assertEq(Reflect.setPrototypeOf(proto, obj), false);
// Don't create a longish [[Prototype]] cycle.
for (var i = 0; i < 256; i++)
obj = Object.create(obj);
assertEq(Reflect.setPrototypeOf(proto, obj), false);
// The spec claims we should allow creating cycles involving proxies. (The
// cycle check quietly exits on encountering the proxy.)
obj = {};
var proxy = new Proxy(Object.create(obj), {});
assertEq(Reflect.setPrototypeOf(obj, proxy), true);
assertEq(Reflect.getPrototypeOf(obj), proxy);
assertEq(Reflect.getPrototypeOf(proxy), obj);
// If a proxy handler returns a false-y value, return false.
var hits = 0;
proto = {name: "proto"};
obj = {name: "obj"};
proxy = new Proxy(obj, {
setPrototypeOf(t, p) {
assertEq(t, obj);
assertEq(p, proto);
hits++;
return 0;
}
});
assertEq(Reflect.setPrototypeOf(proxy, proto), false);
assertEq(hits, 1);
// For more Reflect.setPrototypeOf tests, see target.js.
reportCompare(0, 0);
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