node/deps/v8/test/mjsunit/keyed-load-hole-to-undefined.js
Michaël Zasso 2dcc3665ab
deps: update V8 to 7.6.303.28
PR-URL: https://github.com/nodejs/node/pull/28016
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann (רפאל פלחי) <refack@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
2019-08-01 12:53:56 +02:00

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862 B
JavaScript

// 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: --allow-natives-syntax --no-stress-opt --opt --no-always-opt
// --nostress-opt is specified because the test corrupts the "pristine"
// array prototype chain by storing an element, and this is tracked
// per-isolate. A subsequent stress run would send the load generic,
// and no more deoptimizations of foo would occur.
function foo(a, i) { return a[i]; }
%PrepareFunctionForOptimization(foo);
var a = ['one', , 'three'];
foo(a, 0);
foo(a, 0);
foo(a, 0);
%OptimizeFunctionOnNextCall(foo);
assertEquals(undefined, foo(a, 1));
assertOptimized(foo);
// Whereas if we disrupt the prototype chain...
Array.prototype[1] = 'cow';
assertEquals('cow', foo(a, 1));
assertUnoptimized(foo);