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Kmake/deps/v8/test/mjsunit/maglev/regress/regress-1407959.js

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2026-05-26 23:36:42 -07:00
// Copyright 2023 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: --maglev --allow-natives-syntax
function func() {}
function foo(x) {
return x instanceof func;
}
%PrepareFunctionForOptimization(foo);
foo();
foo();
%OptimizeMaglevOnNextCall(foo);
foo();
let custom_has_instance_runs = 0;
Object.defineProperty(func, Symbol.hasInstance, {
value: function() {
custom_has_instance_runs++;
return true;
}
});
assertTrue(foo());
assertEquals(custom_has_instance_runs, 1);