function run_test() { let Cu = Components.utils; let sandbox1 = new Cu.Sandbox(null); let sandbox2 = new Cu.Sandbox(null); let arg = Cu.evalInSandbox('({ buf: new ArrayBuffer(2) })', sandbox1); let clonedArg = Cu.cloneInto(Cu.waiveXrays(arg), sandbox2); do_check_eq(typeof Cu.waiveXrays(clonedArg).buf, "object"); clonedArg = Cu.cloneInto(arg, sandbox2); do_check_eq(typeof Cu.waiveXrays(clonedArg).buf, "object"); do_check_eq(Cu.waiveXrays(clonedArg).buf.constructor.name, "ArrayBuffer"); }