function shouldBe(actual, expected) { if (actual !== expected) throw new Error('bad value: ' + actual); } function test() { var set = new WeakSet(); var key = {}; var key2 = {}; set.add(key); set.add(key2); if (set.has(key)) return set.has(key); return 0; } noInline(test); for (var i = 0; i < 1e6; ++i) shouldBe(test(), true);