export default { data: { x: true, value: 'one' }, html: ` <div> <input> <span>x</span> </div> `, nestedTransitions: true, test(assert, component, target, window, raf) { const div = target.querySelector('div'); const { appendChild, insertBefore } = div; div.appendChild = div.insertBefore = () => { throw new Error('DOM was mutated'); }; component.set({ value: 'two' }); }, };