function shouldBe(actual, expected) { if (actual !== expected) throw new Error('bad value: ' + actual); } var k = -1; var o1 = ["Cocoa"]; o1[k] = 42; function test1(o) { return k in o; } noInline(test1); for (var i = 0; i < 1e6; ++i) shouldBe(test1(o1), true);