Merge pull request #1329 from gsathya/promise-finally-species-constructor

Promise.p.finally: test SpeciesConstructor and Symbol.species lookup

test/built-ins/Promise/prototype/finally/species-constructor.js

+// Copyright (C) 2017 V8. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+author: Sathya Gunasekaran
+description: finally calls the SpeciesConstructor
+esid: sec-promise.prototype.finally
+features: [Promise.prototype.finally]
+flags: [async]
+---*/
+
+
+var count = 0;
+class FooPromise extends Promise {
+  constructor(resolve, reject) {
+    count++;
+    return super(resolve, reject);
+  }
+}
+
+new FooPromise(r => r())
+  .finally(() => {})
+  .then(() => {
+    assert.sameValue(count, 6, "6 new promises were created");
+    $DONE();
+});

test/built-ins/Promise/prototype/finally/species-symbol.js

+// Copyright (C) 2017 V8. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+author: Sathya Gunasekaran
+description: finally calls the SpeciesConstructor
+esid: sec-promise.prototype.finally
+features: [Promise.prototype.finally]
+---*/
+
+
+class MyPromise extends Promise {
+  static get [Symbol.species]() { return Promise; }
+}
+
+var p = Promise
+    .resolve()
+    .finally(() => MyPromise.resolve());
+
+assert.sameValue(true, p instanceof Promise);
+assert.sameValue(false, p instanceof MyPromise);