Describe the bug

useVModels mistakenly marks the returned ref object as possibly undefined if the respective property is optional.

This is not correct. The ref is always returned. The ref value is possibly undefined, but not the ref object itself.

Example:

const props = defineProps<{
  foo: string;
  bar?: string;
}>();

const emit = defineEmits<{
  'update:foo': [foo: string];
  'update:bar': [bar: string | undefined];
}>();

const { foo, bar } = useVModels(props, emit);
const bar2 = useVModel(props, 'bar', emit);

foo.value = 'foo'; // OK
bar.value = 'bar'; // 'bar' is possibly 'undefined' <------ Type error (but no runtime error)
bar2.value = 'bar2'; // OK

How to reproduce: in StackBlitz, run npm test.

Reproduction

https://stackblitz.com/edit/nuxt-starter-vj3utk?file=components%2Ftest.vue

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.18.0 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 9.4.2 - /usr/local/bin/npm
    pnpm: 8.9.2 - /usr/local/bin/pnpm
  npmPackages:
    @vueuse/core: ^10.6.1 => 10.6.1

Used Package Manager

npm

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a VueUse issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion.
• The provided reproduction is a minimal reproducible example of the bug.