Define a macro for returning the setup object

[matthew-dean]

Use case

I'm converting a Knockout site to Vue, which separates all models / methods / variables into classes.

Without using <script setup> you can do this:

<script lang="ts">
import { defineComponent } from 'vue'
import { TagsModel } from './TagsVm'

export default defineComponent({
  // ...
  setup(props) {
    return TagsModel(props)
  }
</script>

However, I'd much rather use <script setup>, but as far as I know, there's no way to "assign" the return value object to mimic the same pattern here.

Proposal

Something like defineScope which allows you to return an object that will be bound to the template, exactly the same as the return value of setup()

<script setup lang="ts">
import { defineComponent } from 'vue'
import { TagsModel } from './TagsVm'

defineScope(TagsModel(props))
</script>

[matthew-dean]

Note, apparently, TypeScript thinks it's fine to write:

<script setup>
import { TagsModel } from './TagsVm'
defineOptions({
  setup(props) {
    return TagsModel(props)
  }
})
</script>

However, it's not clear that would actually work, and Volar doesn't know how to interpret the return types.