Function setup

packages/runtime-core/__tests__/hydration.spec.ts:538–545

()

    let foo: any
    const App = {
      setup() {
        const flag = ref(true)
        foo = () => {
          flag.value = false
        }
        onServerPrefetch(() => (flag.value = false))
        return { flag }
      },
      components: {
        Comp,
      },