InputText and DatePicker emit types include unreachable undefined, breaking strictTemplates

[YevheniiKotyrlo]

Describe the bug

InputText and DatePicker declare | undefined in their update:modelValue and value-change emit signatures, but neither component can emit undefined at runtime.

With strictTemplates: true in vue-tsc, the emitted | undefined is not assignable to the consumer's ref type (e.g., Ref<string> for InputText), producing 39 false-positive type errors.

InputText: Single emission path: onInput(event) -> writeValue(event.target.value). HTMLInputElement.value is always string per HTML spec. Full inheritance chain audited — no path can emit undefined.

DatePicker: All 9 emission paths traced through updateModel() -> writeValue() -> $emit(). Clear button emits null. Invalid text input throws (no emission). 7 edge cases pressure-tested. undefined is never passed to writeValue().

Related: #6041

PrimeVue version

4.5.4

Vue version

3.5.x

Language

TypeScript

Build / Runtime

Vite

Steps to reproduce the behavior

1. Enable strictTemplates: true in tsconfig.json under vueCompilerOptions
2. Use <InputText v-model="myString" /> where myString is ref<string>('')
3. Run vue-tsc --noEmit
4. Observe: Type 'string | undefined' is not assignable to type 'string'

Expected behavior

No type error — InputText always emits string, never undefined.