[es6] Align Promise.resolve with the spec

test/mjsunit/es6/promises.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 993 matching lines @@
   var p1 = new MyPromise(function(resolve, reject) { resolve(1) })
   var p2 = new MyPromise(function(resolve, reject) { reject(2) })
   var d3 = MyPromise.defer()
   assertTrue(d3.promise instanceof Promise, "subclass/instance")
   assertTrue(d3.promise instanceof MyPromise, "subclass/instance-my3")
   assertTrue(log === "nx1nr2dn", "subclass/create")
 
   log = ""
   var p4 = MyPromise.resolve(4)
   var p5 = MyPromise.reject(5)
-  assertTrue(p4 instanceof Promise, "subclass/instance4")
+  assertTrue(p4 instanceof MyPromise, "subclass/instance4")
   assertTrue(p4 instanceof MyPromise, "subclass/instance-my4")
-  assertTrue(p5 instanceof Promise, "subclass/instance5")
+  assertTrue(p5 instanceof MyPromise, "subclass/instance5")
   assertTrue(p5 instanceof MyPromise, "subclass/instance-my5")
   d3.resolve(3)
   assertTrue(log === "nx4nr5x3", "subclass/resolve")
 
   log = ""
   var d6 = MyPromise.defer()
   d6.promise.chain(function(x) {
     return new Promise(function(resolve) { resolve(x) })
   }).chain(function() {})
   d6.resolve(6)
   assertTrue(log === "dncncnx6", "subclass/chain")
 
   log = ""
   Promise.all([11, Promise.accept(12), 13, MyPromise.accept(14), 15, 16])
-  assertTrue(log === "nx14n", "subclass/all/arg")
+
+  assertTrue(log === "nx14", "subclass/all/arg")
 
   log = ""
   MyPromise.all([21, Promise.accept(22), 23, MyPromise.accept(24), 25, 26])
-  assertTrue(log === "nx24nnx21nnx23nnnx25nnx26n", "subclass/all/self")
+  assertTrue(log === "nx24nnx21nnnnx23nnnx25nnx26n", "subclass/all/self")
 })();
 
+(function() {
+  'use strict';
+
+  class Pact extends Promise { }
+  class Vow  extends Pact    { }
+  class Oath extends Vow     { }
+
+  Oath.constructor = Vow;
+
+  assertTrue(Pact.resolve(Pact.resolve()).constructor === Pact,
+             "subclass/resolve/own");
+
+  assertTrue(Pact.resolve(Promise.resolve()).constructor === Pact,
+             "subclass/resolve/ancestor");
+
+  assertTrue(Pact.resolve(Vow.resolve()).constructor === Pact,
+             "subclass/resolve/descendant"); var vow = Vow.resolve();
+
+  vow.constructor = Oath;
+  assertTrue(Oath.resolve(vow) === vow,
+             "subclass/resolve/descendant with transplanted own constructor");
+}());
 
 assertAsyncDone()