Broken types when using render functions with generic components & defineModel

[DrWarpMan]

Vue version

3.5.12

Link to minimal reproduction

https://github.com/DrWarpMan/vue-generic-bug

Steps to reproduce

The bug is described in the comments of the code.

App.vue

<script setup lang="ts">
import { h, ref } from 'vue';
import Comp from './Comp.vue';

const foo = ref<string>('foo');

// val should be of type 'string', not 'unknown'
const FunctionalComponent = () => h(Comp, {
  /* unknown */ modelValue: foo.value, 
  ['onUpdate:modelValue']: (val /* unknown */) => foo.value = val,
});
</script>

<template />

Comp.vue

<script setup lang="ts" generic="T">
defineModel<T>({required: true});
</script>

<template />

What is expected?

Render functions should have proper type based on the provided value to the generic component.

What is actually happening?

Render functions have 'unknown' type, regardless of the provided value to the generic component.

System Info

No response

Any additional comments?

Issue was moved from language-tools repo.

[edison1105]

should be

const FunctionalComponent = () => h(Comp<string>, {
  modelValue: foo.value, 
  ['onUpdate:modelValue']: (val) => foo.value = val,
});

[DrWarpMan]

So you have to manually specify it, it can't get inferred?

[edison1105]

For generic components, you need to specify the type; there is no way to infer it automatically.

[DrWarpMan]

Okay, now that I see it, it seems pretty straightforward, but I wonder if this should be mentioned somewhere in the docs?

In any case, the issue can be closed.