Generic components using defineComponent

[tobiasdiez]

We can conveniently declare generic components using <script setup lang="ts" generic="T"> and

defineComponent(
  <T extends string | number>(props: { msg: T; list: T[] }) => {
    ...
  },

However, the latter method only allows to use the generic type in the render method, and not say for the slots.

For example,

<script setup lang="ts" generic="TArgs">
defineProps<{
  argTypes: TArgs
}>()
defineSlots<{
  default(props: { args: TArgs }): any
}>()
</script>

is compiled to something of the form <TArgs> (__VLS_props: { argTypes: TArgs; } ... { slots in terms of TArgs } ... while the defineComponent method doesn't allow to easily share the types between the render method and slots.

This is particularly relevant for library maintainers that would like to (only) define the type of a generic component and don't want to define the component using SFC.