fix(virtualscroller,selectbutton,inputchips): enable generic type inference for items and slots

[YevheniiKotyrlo]

Defect Fixes

Fixes #8492

VirtualScroller, SelectButton, and InputChips use any for their collection props and slot scoped data. These are the last three PrimeVue components where collection props flow to slots without generic type inference.

Same root cause as #8442 — DefineComponent's no-arg constructor prevents generic inference. Same fix pattern as #8444 (DataTable/DatePicker).

Related: #7426, #6041

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

Problem

<SelectButton :options="cities" :optionLabel="(city) => city.name">
  <template #option="{ option }">
    {{ option.naem }}
    <!-- No error — `option` is `any`, typo ships to production -->
  </template>
</SelectButton>

After this fix, TypeScript infers T from the collection prop and flows it to all slots:

<SelectButton :options="cities" :optionLabel="(city) => city.name">
  <template #option="{ option }">
    {{ option.naem }}
    <!-- TS2339: Property 'naem' does not exist on type 'City' -->
  </template>
</SelectButton>

Changes

VirtualScroller:

• VirtualScrollerProps<T = any>: items?: T[] | T[][]
• VirtualScrollerSlots<T = any>: item slot item: T, content slot items: T[]

SelectButton:

• SelectButtonProps<T = any>: options?: T[], callbacks (data: T) => ...
• SelectButtonSlots<T = any>: option slot option: T
• modelValue stays any — optionValue extracts a scalar, same reasoning as Select (fix(select,multiselect,listbox): enable generic type inference for options and slots #8484)

InputChips:

• InputChipsProps<T = any>: modelValue?: T[]
• InputChipsSlots<T = any>: chip slot value: T
• modelValue becomes T[] — items ARE the value (no optionValue), same reasoning as OrderList (fix(orderlist,picklist): enable generic type inference for items and slots #8491)

Each component uses the generic constructor pattern (new <T>(props)) so TypeScript infers T automatically.

What gets typed

Slot/Callback	Before	After
VirtualScroller #item slot item	any	T
VirtualScroller #content slot items	any	T[]
SelectButton #option slot option	any	T
SelectButton optionLabel callback param	any	T
SelectButton optionValue callback param	any	T
SelectButton optionDisabled callback param	any	T
InputChips #chip slot value	any	T
InputChips modelValue	any[]	T[]

Scope / Impact

• No breaking changes — backward compatible, T defaults to any
• No runtime changes — types only (.d.ts files)
• 3 components: VirtualScroller, SelectButton, InputChips

Verification

Gate	Result
pnpm run format:check	PASS
pnpm run lint	PASS
pnpm run test:unit	Pre-existing failures only, 0 new
pnpm run build:packages (primevue)	PASS
Type pressure test (4 @ts-expect-error checks)	PASS

Series

This is the final PR in a series bringing generic type inference to all PrimeVue data components:

PR	Components	Status
#8444	DataTable, DatePicker	Open
#8484	Select, MultiSelect, Listbox	Open
#8485	Column (phantom of prop)	Open
#8489	AutoComplete, CascadeSelect, DataView	Open
#8490	Carousel, Galleria, Timeline	Open
#8491	OrderList, PickList	Open
#8493	VirtualScroller, SelectButton, InputChips	This PR

After this series, every PrimeVue component with a collection prop infers T from the binding and flows it to slots — giving developers full IDE autocomplete and compile-time type safety in templates.