[typedarrays] Move %TypedArray%.prototype.slice to C++

test/mjsunit/es6/typedarray-slice.js

 // Copyright 2015 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.
 
 var typedArrayConstructors = [
   Uint8Array,
   Int8Array,
   Uint16Array,
   Int16Array,
   Uint32Array,
@@ skipping 50 matching lines @@
     constructor.prototype.slice.call([], 0, 0);
   }, TypeError);
 
   // Check that elements are copied properly in slice
   array = new constructor([1, 2, 3, 4]);
   var slice = array.slice(1, 3);
   assertEquals(2, slice.length);
   assertEquals(2, slice[0]);
   assertEquals(3, slice[1]);
   assertTrue(slice instanceof constructor);
+
+  // Check that the result array is properly created by checking species

[Camillo Bruni, 2017/03/20 13:37:25]

Could you extend this and add specific tests with a subclass of each TypedArray?
I'd like to have coverage when and if you add all the special casing in
ElementsAccessor :).

[Choongwoo Han, 2017/03/21 12:39:03]

Done.

+  class MyFloat64Array extends Float64Array {
+    static get[Symbol.species]() {
+      return constructor;
+    }
+  }
+  var arr = new MyFloat64Array([-1.0, 0, 255, 256]);
+  assertEquals(new constructor([-1.0, 0, 255, 256]), arr.slice());
+
+  class MyTypedArray extends constructor {
+    static get[Symbol.species]() {
+      return Array;
+    }
+  }
+  var arr = new MyTypedArray([-1.0, 0, 255, 256]);
+  assertThrows(() => arr.slice(), TypeError);
 }