Function renderAutosave

apps/sim/hooks/use-autosave.test.tsx:29–59

* Minimal dependency-free hook harness (the repo has no `@testing-library/react`). Mounts the hook * in a real React 19 root under jsdom so effects, refs, and timers run exactly as in the app.

(initial: ProbeProps)

 * in a real React 19 root under jsdom so effects, refs, and timers run exactly as in the app.
 */
function renderAutosave(initial: ProbeProps): { handle: HookHandle; props: ProbeProps } {
  ;(globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true
  const container = document.createElement('div')
  const root: Root = createRoot(container)
  const props = { ...initial }
  let latest = { saveStatus: 'idle' as SaveStatus, isDirty: false, saveImmediately: async () => {} }

  function Probe(p: ProbeProps) {
    latest = useAutosave(p)
    return null
  }

  const render = () => {
    act(() => {
      root.render(<Probe {...props} />)
    })
  }
  render()

  const handle: HookHandle = {
    status: () => latest.saveStatus,
    isDirty: () => latest.isDirty,
    saveImmediately: () => latest.saveImmediately(),
    rerender: (next) => {
      Object.assign(props, next)
      render()
    },
    unmount: () => act(() => root.unmount()),
  }
  return { handle, props }
}

/** Flush pending microtasks (awaited promises) inside an act() boundary. */
async function flush() {