VirtualScroller, SelectButton, InputChips: generic type not inferred from items/options/modelValue

[YevheniiKotyrlo]

Describe the bug

When using VirtualScroller, SelectButton, or InputChips with typed collections, TypeScript cannot infer the item/option type in slots and callbacks. Slot parameters and callback arguments remain typed as any, losing type safety.

VirtualScroller:

<VirtualScroller :items="products">
  <template #item="{ item }">
    <!-- item is any, should be Product -->
    {{ item.name }}
  </template>
</VirtualScroller>

SelectButton:

<SelectButton
  :options="cities"
  :option-label="(city) => city.name"
>
  <!-- city parameter is any, should be City -->
  <template #option="{ option }">
    <!-- option is any, should be City -->
    {{ option.name }}
  </template>
</SelectButton>

InputChips:

<InputChips :model-value="tags">
  <template #chip="{ value }">
    <!-- value is any, should be Tag -->
    {{ value.label }}
  </template>
</InputChips>

Reproducer: StackBlitz — bun run type-check (0 errors, typo undetected) → bun run patch && bun run type-check (TS2339 catches it)

Reproducer

https://stackblitz.com/github/YevheniiKotyrlo/primevue-generic-type-repro?file=src%2FApp.vue

Pull Request Link

#8493

PrimeVue version

4.5.4

Vue version

3.x

Language

TypeScript

Build / Runtime

Vite

Browser(s)

N/A (type-level issue)

Steps to reproduce the behavior

1. Pass a typed array to VirtualScroller items, SelectButton options, or InputChips modelValue
2. Use the #item, #option, or #chip slot
3. The slot parameter is typed as any instead of the array element type

Expected behavior

TypeScript should infer the generic type T from the collection prop and propagate it to slot parameters and callback arguments, providing full type safety without explicit annotations.