Test that TypedArray methods don't read length

test/mjsunit/harmony/typedarray-fill.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.
 
 // Flags: --harmony-arrays
 
 var typedArrayConstructors = [
   Uint8Array,
   Int8Array,
   Uint16Array,
@@ skipping 18 matching lines @@
   assertArrayEquals(new constructor([0, 0, 0, 0, 0]).fill(8, -3, 42), [0, 0, 8, 8, 8]);
   assertArrayEquals(new constructor([0, 0, 0, 0, 0]).fill(8, -3, 4), [0, 0, 8, 8, 0]);
   assertArrayEquals(new constructor([0, 0, 0, 0, 0]).fill(8, -2, -1), [0, 0, 0, 8, 0]);
   assertArrayEquals(new constructor([0, 0, 0, 0, 0]).fill(8, -1, -3), [0, 0, 0, 0, 0]);
   assertArrayEquals(new constructor([0, 0, 0, 0, 0]).fill(8, 0, 4), [8, 8, 8, 8, 0]);
 
   // Test exceptions
   assertThrows('constructor.prototype.fill.call(null)', TypeError);
   assertThrows('constructor.prototype.fill.call(undefined)', TypeError);
   assertThrows('constructor.prototype.fill.call([])', TypeError);
+
+  // Shadowing length doesn't affect fill, unlike Array.prototype.fill
+  var a = new constructor([2, 2]);
+  Object.defineProperty(a, 'length', {value: 1});

[arv (Not doing code reviews), 2015/05/15 00:25:47]

or

get: function() { assertUnreachable(); }

[dehrenberg, 2015/05/15 01:40:41]

well, later down I validate the test by making it get reached by
Array.prototype.fill, so not sure if that would really work the way it's
written.

+  a.fill(3);
+  assertArrayEquals([a[0], a[1]], [3, 3]);
+  Array.prototype.fill.call(a, 4);
+  assertArrayEquals([a[0], a[1]], [4, 3]);
 }