/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

const GeneratorFunction = function*(){}.constructor;


// Test subclassing %GeneratorFunction% works correctly.
class MyGenerator extends GeneratorFunction {}

var fn = new MyGenerator();
assertEq(fn instanceof MyGenerator, true);
assertEq(fn instanceof GeneratorFunction, true);
assertEq(Object.getPrototypeOf(fn), MyGenerator.prototype);

fn = Reflect.construct(MyGenerator, []);
assertEq(fn instanceof MyGenerator, true);
assertEq(fn instanceof GeneratorFunction, true);
assertEq(Object.getPrototypeOf(fn), MyGenerator.prototype);

fn = Reflect.construct(MyGenerator, [], MyGenerator);
assertEq(fn instanceof MyGenerator, true);
assertEq(fn instanceof GeneratorFunction, true);
assertEq(Object.getPrototypeOf(fn), MyGenerator.prototype);

fn = Reflect.construct(MyGenerator, [], GeneratorFunction);
assertEq(fn instanceof MyGenerator, false);
assertEq(fn instanceof GeneratorFunction, true);
assertEq(Object.getPrototypeOf(fn), GeneratorFunction.prototype);


// Set a different constructor as NewTarget.
fn = Reflect.construct(MyGenerator, [], Array);
assertEq(fn instanceof MyGenerator, false);
assertEq(fn instanceof GeneratorFunction, false);
assertEq(Object.getPrototypeOf(fn), Array.prototype);

fn = Reflect.construct(GeneratorFunction, [], Array);
assertEq(fn instanceof GeneratorFunction, false);
assertEq(Object.getPrototypeOf(fn), Array.prototype);


// The prototype defaults to %GeneratorFunctionPrototype% if null.
function NewTargetNullPrototype() {}
NewTargetNullPrototype.prototype = null;

fn = Reflect.construct(GeneratorFunction, [], NewTargetNullPrototype);
assertEq(fn instanceof GeneratorFunction, true);
assertEq(Object.getPrototypeOf(fn), GeneratorFunction.prototype);

fn = Reflect.construct(MyGenerator, [], NewTargetNullPrototype);
assertEq(fn instanceof MyGenerator, false);
assertEq(fn instanceof GeneratorFunction, true);
assertEq(Object.getPrototypeOf(fn), GeneratorFunction.prototype);


// "prototype" property is retrieved exactly once.
var trapLog = [], getLog = [];
var ProxiedConstructor = new Proxy(GeneratorFunction, new Proxy({
    get(target, propertyKey, receiver) {
        getLog.push(propertyKey);
        return Reflect.get(target, propertyKey, receiver);
    }
}, {
    get(target, propertyKey, receiver) {
        trapLog.push(propertyKey);
        return Reflect.get(target, propertyKey, receiver);
    }
}));

fn = Reflect.construct(GeneratorFunction, [], ProxiedConstructor);
assertEqArray(trapLog, ["get"]);
assertEqArray(getLog, ["prototype"]);
assertEq(fn instanceof GeneratorFunction, true);
assertEq(Object.getPrototypeOf(fn), GeneratorFunction.prototype);


if (typeof reportCompare === "function")
    reportCompare(0, 0);