fix(InputMenu/Select/SelectMenu): improve types (#2471)

playground/app/pages/components/input-menu.vue

@@ -11,7 +11,7 @@ const fruits = ['Apple', 'Banana', 'Blueberry', 'Grapes', 'Pineapple']
 const vegetables = ['Aubergine', 'Broccoli', 'Carrot', 'Courgette', 'Leek']
 
 const items = [[{ label: 'Fruits', type: 'label' }, ...fruits], [{ label: 'Vegetables', type: 'label' }, ...vegetables]]
-const selectedItems = ref([fruits[0], vegetables[0]])
+const selectedItems = ref([fruits[0]!, vegetables[0]!])
 
 const statuses = [{
   label: 'Backlog',
@@ -135,7 +135,7 @@ const { data: users, status } = await useFetch('https://jsonplaceholder.typicode
         v-for="size in sizes"
         :key="size"
         :items="items"
-        :model-value="[fruits[0]]"
+        :model-value="[fruits[0]!]"
         multiple
         icon="i-heroicons-magnifying-glass"
         placeholder="Search..."

playground/app/pages/components/select-menu.vue

@@ -11,7 +11,7 @@ const fruits = ['Apple', 'Banana', 'Blueberry', 'Grapes', 'Pineapple']
 const vegetables = ['Aubergine', 'Broccoli', 'Carrot', 'Courgette', 'Leek']
 
 const items = [[{ label: 'Fruits', type: 'label' }, ...fruits], [{ label: 'Vegetables', type: 'label' }, ...vegetables]]
-const selectedItems = ref([fruits[0], vegetables[0]])
+const selectedItems = ref([fruits[0]!, vegetables[0]!])
 
 const statuses = [{
   label: 'Backlog',

src/runtime/components/InputMenu.vue

@@ -7,7 +7,7 @@ import _appConfig from '#build/app.config'
 import theme from '#build/ui/input-menu'
 import type { UseComponentIconsProps } from '../composables/useComponentIcons'
 import type { AvatarProps, ChipProps, InputProps } from '../types'
-import type { AcceptableValue, ArrayOrWrapped, PartialString } from '../types/utils'
+import type { AcceptableValue, ArrayOrWrapped, PartialString, SelectItems, SelectItemType, SelectModelValue, SelectModelValueEmits, SelectItemKey } from '../types/utils'
 
 const appConfig = _appConfig as AppConfig & { ui: { inputMenu: Partial<typeof theme> } }
 
@@ -29,7 +29,7 @@ export interface InputMenuItem {
 
 type InputMenuVariants = VariantProps<typeof inputMenu>
 
-export interface InputMenuProps<T> extends Pick<ComboboxRootProps<T>, 'modelValue' | 'defaultValue' | 'selectedValue' | 'open' | 'defaultOpen' | 'searchTerm' | 'multiple' | 'disabled' | 'name' | 'resetSearchTermOnBlur'>, UseComponentIconsProps {
+export interface InputMenuProps<T extends SelectItemType<I>, I extends SelectItems<InputMenuItem | AcceptableValue> = SelectItems<InputMenuItem | AcceptableValue>, V extends SelectItemKey<T> | undefined = undefined, M extends boolean = false> extends Pick<ComboboxRootProps<T>, 'defaultValue' | 'selectedValue' | 'open' | 'defaultOpen' | 'searchTerm' | 'disabled' | 'name' | 'resetSearchTermOnBlur'>, UseComponentIconsProps {
   /**
    * The element or component this component should render as.
    * @defaultValue 'div'
@@ -86,24 +86,28 @@ export interface InputMenuProps<T> extends Pick<ComboboxRootProps<T>, 'modelValu
    * When `items` is an array of objects, select the field to use as the value instead of the object itself.
    * @defaultValue undefined
    */
-  valueKey?: keyof T
+  valueKey?: V
   /**
    * When `items` is an array of objects, select the field to use as the label.
    * @defaultValue 'label'
    */
   labelKey?: keyof T
-  items?: T[] | T[][]
+  items?: I
   /** Highlight the ring color like a focus state. */
   highlight?: boolean
   class?: any
   ui?: PartialString<typeof inputMenu.slots>
+  /** The controlled value of the Combobox. Can be binded-with with `v-model`. */
+  modelValue?: SelectModelValue<T, V, M>
+  /** Whether multiple options can be selected or not. */
+  multiple?: M
 }
 
-export type InputMenuEmits<T> = ComboboxRootEmits<T> & {
+export type InputMenuEmits<T, V, M extends boolean> = Omit<ComboboxRootEmits<T>, 'update:modelValue'> & {
   change: [payload: Event]
   blur: [payload: FocusEvent]
   focus: [payload: FocusEvent]
-}
+} & SelectModelValueEmits<T, V, M>
 
 type SlotProps<T> = (props: { item: T, index: number }) => any
 
@@ -120,7 +124,7 @@ export interface InputMenuSlots<T> {
 }
 </script>
 
-<script setup lang="ts" generic="T extends InputMenuItem | AcceptableValue">
+<script setup lang="ts" generic="T extends SelectItemType<I>, I extends SelectItems<InputMenuItem | AcceptableValue> = SelectItems<InputMenuItem | AcceptableValue>, V extends SelectItemKey<T> | undefined = undefined, M extends boolean = false">
 import { computed, ref, toRef, onMounted } from 'vue'
 import { ComboboxRoot, ComboboxAnchor, ComboboxInput, ComboboxTrigger, ComboboxPortal, ComboboxContent, ComboboxViewport, ComboboxEmpty, ComboboxGroup, ComboboxLabel, ComboboxSeparator, ComboboxItem, ComboboxItemIndicator, TagsInputRoot, TagsInputItem, TagsInputItemText, TagsInputItemDelete, TagsInputInput, useForwardPropsEmits } from 'radix-vue'
 import { defu } from 'defu'
@@ -137,14 +141,14 @@ import UChip from './Chip.vue'
 
 defineOptions({ inheritAttrs: false })
 
-const props = withDefaults(defineProps<InputMenuProps<T>>(), {
+const props = withDefaults(defineProps<InputMenuProps<T, I, V, M>>(), {
   type: 'text',
   autofocusDelay: 0,
   portal: true,
   filter: () => ['label'],
   labelKey: 'label' as keyof T
 })
-const emits = defineEmits<InputMenuEmits<T>>()
+const emits = defineEmits<InputMenuEmits<T, V, M>>()
 const slots = defineSlots<InputMenuSlots<T>>()
 
 const searchTerm = defineModel<string>('searchTerm', { default: '' })

src/runtime/components/Select.vue

@@ -6,7 +6,7 @@ import _appConfig from '#build/app.config'
 import theme from '#build/ui/select'
 import type { UseComponentIconsProps } from '../composables/useComponentIcons'
 import type { AvatarProps, ChipProps, InputProps } from '../types'
-import type { AcceptableValue, PartialString } from '../types/utils'
+import type { AcceptableValue, PartialString, SelectItems, SelectItemType, SelectModelValue, SelectModelValueEmits, SelectItemKey } from '../types/utils'
 
 const appConfig = _appConfig as AppConfig & { ui: { select: Partial<typeof theme> } }
 
@@ -28,7 +28,7 @@ export interface SelectItem {
 
 type SelectVariants = VariantProps<typeof select>
 
-export interface SelectProps<T> extends Omit<SelectRootProps, 'dir'>, UseComponentIconsProps {
+export interface SelectProps<T extends SelectItemType<I>, I extends SelectItems<SelectItem | AcceptableValue> = SelectItems<SelectItem | AcceptableValue>, V extends SelectItemKey<T> | undefined = undefined> extends Omit<SelectRootProps, 'dir' | 'modelValue'>, UseComponentIconsProps {
   id?: string
   /** The placeholder text when the select is empty. */
   placeholder?: string
@@ -64,24 +64,26 @@ export interface SelectProps<T> extends Omit<SelectRootProps, 'dir'>, UseCompone
    * When `items` is an array of objects, select the field to use as the value.
    * @defaultValue 'value'
    */
-  valueKey?: string
+  valueKey?: V
   /**
    * When `items` is an array of objects, select the field to use as the label.
    * @defaultValue 'label'
    */
-  labelKey?: string
+  labelKey?: SelectItemKey<T>
-  items?: T[] | T[][]
+  items?: I
   /** Highlight the ring color like a focus state. */
   highlight?: boolean
   class?: any
   ui?: PartialString<typeof select.slots>
+  /** The controlled value of the Select. Can be bind as `v-model`. */
+  modelValue?: SelectModelValue<T, V, false, T extends { value: infer U } ? U : never>
 }
 
-export type SelectEmits = SelectRootEmits & {
+export type SelectEmits<T, V> = Omit<SelectRootEmits, 'update:modelValue'> & {
   change: [payload: Event]
   blur: [payload: FocusEvent]
   focus: [payload: FocusEvent]
-}
+} & SelectModelValueEmits<T, V, false, T extends { value: infer U } ? U : never>
 
 type SlotProps<T> = (props: { item: T, index: number }) => any
 
@@ -95,7 +97,7 @@ export interface SelectSlots<T> {
 }
 </script>
 
-<script setup lang="ts" generic="T extends SelectItem | AcceptableValue">
+<script setup lang="ts" generic="T extends SelectItemType<I>, I extends SelectItems<SelectItem | AcceptableValue> = SelectItems<SelectItem | AcceptableValue>, V extends SelectItemKey<T> | undefined = undefined">
 import { computed, toRef } from 'vue'
 import { SelectRoot, SelectTrigger, SelectValue, SelectPortal, SelectContent, SelectViewport, SelectLabel, SelectGroup, SelectItem, SelectItemIndicator, SelectItemText, SelectSeparator, useForwardPropsEmits } from 'radix-vue'
 import { defu } from 'defu'
@@ -109,12 +111,12 @@ import UIcon from './Icon.vue'
 import UAvatar from './Avatar.vue'
 import UChip from './Chip.vue'
 
-const props = withDefaults(defineProps<SelectProps<T>>(), {
+const props = withDefaults(defineProps<SelectProps<T, I, V>>(), {
-  valueKey: 'value',
+  valueKey: 'value' as never,
-  labelKey: 'label',
+  labelKey: 'label' as never,
   portal: true
 })
-const emits = defineEmits<SelectEmits>()
+const emits = defineEmits<SelectEmits<T, V>>()
 const slots = defineSlots<SelectSlots<T>>()
 
 const appConfig = useAppConfig()
@@ -166,6 +168,9 @@ function onUpdateOpen(value: boolean) {
     v-slot="{ modelValue, open }"
     v-bind="rootProps"
     :name="name"
+    :default-value="(defaultValue as string)"
+    :model-value="(modelValue as string)"
+    :autocomplete="autocomplete"
     :disabled="disabled"
     @update:model-value="onUpdate"
     @update:open="onUpdateOpen"

src/runtime/components/SelectMenu.vue

@@ -6,7 +6,7 @@ import _appConfig from '#build/app.config'
 import theme from '#build/ui/select-menu'
 import type { UseComponentIconsProps } from '../composables/useComponentIcons'
 import type { AvatarProps, ChipProps, InputProps } from '../types'
-import type { AcceptableValue, ArrayOrWrapped, PartialString } from '../types/utils'
+import type { AcceptableValue, ArrayOrWrapped, PartialString, SelectItems, SelectItemType, SelectModelValue, SelectModelValueEmits, SelectItemKey } from '../types/utils'
 
 const appConfig = _appConfig as AppConfig & { ui: { selectMenu: Partial<typeof theme> } }
 
@@ -28,7 +28,7 @@ export interface SelectMenuItem {
 
 type SelectMenuVariants = VariantProps<typeof selectMenu>
 
-export interface SelectMenuProps<T> extends Pick<ComboboxRootProps<T>, 'modelValue' | 'defaultValue' | 'selectedValue' | 'open' | 'defaultOpen' | 'searchTerm' | 'multiple' | 'disabled' | 'name' | 'resetSearchTermOnBlur'>, UseComponentIconsProps {
+export interface SelectMenuProps<T extends SelectItemType<I>, I extends SelectItems<SelectMenuItem | AcceptableValue> = SelectItems<SelectMenuItem | AcceptableValue>, V extends SelectItemKey<T> | undefined = undefined, M extends boolean = false> extends Pick<ComboboxRootProps<T>, 'defaultValue' | 'selectedValue' | 'open' | 'defaultOpen' | 'searchTerm' | 'disabled' | 'name' | 'resetSearchTermOnBlur'>, UseComponentIconsProps {
   id?: string
   /** The placeholder text when the select is empty. */
   placeholder?: string
@@ -77,24 +77,28 @@ export interface SelectMenuProps<T> extends Pick<ComboboxRootProps<T>, 'modelVal
    * When `items` is an array of objects, select the field to use as the value instead of the object itself.
    * @defaultValue undefined
    */
-  valueKey?: keyof T
+  valueKey?: V
   /**
    * When `items` is an array of objects, select the field to use as the label.
    * @defaultValue 'label'
    */
-  labelKey?: keyof T
+  labelKey?: SelectItemKey<T>
-  items?: T[] | T[][]
+  items?: I
   /** Highlight the ring color like a focus state. */
   highlight?: boolean
   class?: any
   ui?: PartialString<typeof selectMenu.slots>
+  /** The controlled value of the Combobox. Can be binded-with with `v-model`. */
+  modelValue?: SelectModelValue<T, V, M>
+  /** Whether multiple options can be selected or not. */
+  multiple?: M
 }
 
-export type SelectMenuEmits<T> = ComboboxRootEmits<T> & {
+export type SelectMenuEmits<T, V, M extends boolean> = Omit<ComboboxRootEmits<T>, 'update:modelValue'> & {
   change: [payload: Event]
   blur: [payload: FocusEvent]
   focus: [payload: FocusEvent]
-}
+} & SelectModelValueEmits<T, V, M>
 
 type SlotProps<T> = (props: { item: T, index: number }) => any
 
@@ -110,7 +114,7 @@ export interface SelectMenuSlots<T> {
 }
 </script>
 
-<script setup lang="ts" generic="T extends SelectMenuItem | AcceptableValue">
+<script setup lang="ts" generic="T extends SelectItemType<I>, I extends SelectItems<SelectMenuItem | AcceptableValue> = SelectItems<SelectMenuItem | AcceptableValue>, V extends SelectItemKey<T> | undefined = undefined, M extends boolean = false">
 import { computed, toRef } from 'vue'
 import { ComboboxRoot, ComboboxAnchor, ComboboxInput, ComboboxTrigger, ComboboxPortal, ComboboxContent, ComboboxViewport, ComboboxEmpty, ComboboxGroup, ComboboxLabel, ComboboxSeparator, ComboboxItem, ComboboxItemIndicator, useForwardPropsEmits } from 'radix-vue'
 import { defu } from 'defu'
@@ -125,15 +129,16 @@ import UIcon from './Icon.vue'
 import UAvatar from './Avatar.vue'
 import UChip from './Chip.vue'
 
-const props = withDefaults(defineProps<SelectMenuProps<T>>(), {
+const props = withDefaults(defineProps<SelectMenuProps<T, I, V, M>>(), {
   search: true,
   portal: true,
   autofocusDelay: 0,
   searchInput: () => ({ placeholder: 'Search...' }),
   filter: () => ['label'],
-  labelKey: 'label' as keyof T
+  labelKey: 'label' as never
 })
-const emits = defineEmits<SelectMenuEmits<T>>()
+
+const emits = defineEmits<SelectMenuEmits<T, V, M>>()
 const slots = defineSlots<SelectMenuSlots<T>>()
 
 const searchTerm = defineModel<string>('searchTerm', { default: '' })
@@ -158,7 +163,7 @@ const ui = computed(() => selectMenu({
   buttonGroup: orientation.value
 }))
 
-function displayValue(value: T): string {
+function displayValue(value: T | T[]): string {
   if (props.multiple && Array.isArray(value)) {
     return value.map(v => displayValue(v)).join(', ')
   }
@@ -168,7 +173,7 @@ function displayValue(value: T): string {
   return item && (typeof item === 'object' ? get(item, props.labelKey as string) : item)
 }
 
-function filterFunction(items: ArrayOrWrapped<AcceptableValue>, searchTerm: string): ArrayOrWrapped<AcceptableValue> {
+function filterFunction(items: ArrayOrWrapped<T>, searchTerm: string): ArrayOrWrapped<T> {
   if (props.filter === false) {
     return items
   }
@@ -176,7 +181,7 @@ function filterFunction(items: ArrayOrWrapped<AcceptableValue>, searchTerm: stri
   const fields = Array.isArray(props.filter) ? props.filter : [props.labelKey]
   const escapedSearchTerm = escapeRegExp(searchTerm)
 
-  return items.filter((item) => {
+  return items.filter((item: T) => {
     if (typeof item !== 'object') {
       return String(item).search(new RegExp(escapedSearchTerm, 'i')) !== -1
     }

src/runtime/types/utils.ts

@@ -24,3 +24,11 @@ export type ArrayOrWrapped<T> = T extends any[] ? T : Array<T>
 export type PartialString<T> = {
   [K in keyof T]?: string
 }
+
+export type SelectItems<T> = T[] | T[][]
+export type SelectItemType<I extends SelectItems<unknown>> = I extends (infer U)[][] ? U : I extends (infer U)[] ? U : never
+export type SelectModelValue<T, V, M extends boolean = false, DV = T> = (T extends Record<string, any> ? V extends keyof T ? T[V] : DV : T) extends infer U ? M extends true ? U[] : U : never
+export type SelectItemKey<T> = (T extends Record<string, any> ? keyof T : string)
+export type SelectModelValueEmits<T, V, M extends boolean = false, DV = T> = {
+  'update:modelValue': [payload: SelectModelValue<T, V, M, DV>]
+}

test/components/InputMenu.spec.ts

@@ -5,6 +5,7 @@ import theme from '#build/ui/input'
 import { renderForm } from '../utils/form'
 import { flushPromises, mount } from '@vue/test-utils'
 import type { FormInputEvents } from '~/src/module'
+import { expectEmitPayloadType } from '../utils/types'
 
 describe('InputMenu', () => {
   const sizes = Object.keys(theme.variants.size) as any
@@ -157,5 +158,66 @@ describe('InputMenu', () => {
       await flushPromises()
       expect(wrapper.text()).not.toContain('Error message')
     })
+
+    test('should have the correct types', () => {
+      // with object item
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: [{ label: 'foo', value: 'bar' }]
+      })).toEqualTypeOf<[{ label: string, value: string }]>()
+
+      // with object item and multiple
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: [{ label: 'foo', value: 1 }],
+        multiple: true
+      })).toEqualTypeOf<[{ label: string, value: number }[]]>()
+
+      // with object item and valueKey
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: [{ label: 'foo', value: 'bar' }],
+        valueKey: 'value'
+      })).toEqualTypeOf<[string]>()
+
+      // with object item and multiple and valueKey
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: [{ label: 'foo', value: 1 }],
+        multiple: true,
+        valueKey: 'value'
+      })).toEqualTypeOf<[number[]]>()
+
+      // with string item
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: ['foo']
+      })).toEqualTypeOf<[string]>()
+
+      // with string item and multiple
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: ['foo'],
+        multiple: true
+      })).toEqualTypeOf<[string[]]>()
+
+      // with groups
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: [['foo']]
+      })).toEqualTypeOf<[string]>()
+
+      // with groups and multiple
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: [['foo']],
+        multiple: true
+      })).toEqualTypeOf<[string[]]>()
+
+      // with groups, multiple and mixed types
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: [['foo', { value: 1 }], [{ value: 'bar' }, 2]],
+        multiple: true
+      })).toEqualTypeOf<[(string | number | { value: string } | { value: number })[]]>()
+
+      // with groups, multiple, mixed types and valueKey
+      expectEmitPayloadType('update:modelValue', () => InputMenu({
+        items: [['foo', { value: 1 }], [{ value: 'bar' }, 2]],
+        multiple: true,
+        valueKey: 'value'
+      })).toEqualTypeOf<[(string | number)[]]>()
+    })
   })
 })

test/components/Select.spec.ts

@@ -5,6 +5,7 @@ import ComponentRender from '../component-render'
 import theme from '#build/ui/input'
 import { renderForm } from '../utils/form'
 import type { FormInputEvents } from '~/src/module'
+import { expectEmitPayloadType } from '../utils/types'
 
 describe('Select', () => {
   const sizes = Object.keys(theme.variants.size) as any
@@ -166,5 +167,33 @@ describe('Select', () => {
       await flushPromises()
       expect(wrapper.text()).not.toContain('Error message')
     })
+
+    test('should have the correct types', () => {
+      // with object item
+      expectEmitPayloadType('update:modelValue', () => Select({
+        items: [{ label: 'foo', value: 'bar' }]
+      })).toEqualTypeOf<[string]>()
+
+      // with string item
+      expectEmitPayloadType('update:modelValue', () => Select({
+        items: ['foo']
+      })).toEqualTypeOf<[string]>()
+
+      // with groups
+      expectEmitPayloadType('update:modelValue', () => Select({
+        items: [['foo']]
+      })).toEqualTypeOf<[string]>()
+
+      // with groups and mixed types
+      expectEmitPayloadType('update:modelValue', () => Select({
+        items: [['foo', { value: 1 }], [{ value: 'bar' }, 2]]
+      })).toEqualTypeOf<[string | number]>()
+
+      // with groups, mixed types and valueKey = undefined
+      expectEmitPayloadType('update:modelValue', () => Select({
+        items: [['foo', { value: 1 }], [{ value: 'bar' }, 2]],
+        valueKey: undefined
+      })).toEqualTypeOf<[string | number]>()
+    })
   })
 })

test/components/SelectMenu.spec.ts

@@ -5,6 +5,7 @@ import theme from '#build/ui/input'
 import { renderForm } from '../utils/form'
 import { flushPromises, mount } from '@vue/test-utils'
 import type { FormInputEvents } from '~/src/module'
+import { expectEmitPayloadType } from '../utils/types'
 
 describe('SelectMenu', () => {
   const sizes = Object.keys(theme.variants.size) as any
@@ -161,5 +162,66 @@ describe('SelectMenu', () => {
       await flushPromises()
       expect(wrapper.text()).not.toContain('Error message')
     })
+
+    test('should have the correct types', () => {
+      // with object item
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: [{ label: 'foo', value: 'bar' }]
+      })).toEqualTypeOf<[{ label: string, value: string }]>()
+
+      // with object item and multiple
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: [{ label: 'foo', value: 1 }],
+        multiple: true
+      })).toEqualTypeOf<[{ label: string, value: number }[]]>()
+
+      // with object item and valueKey
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: [{ label: 'foo', value: 'bar' }],
+        valueKey: 'value'
+      })).toEqualTypeOf<[string]>()
+
+      // with object item and multiple and valueKey
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: [{ label: 'foo', value: 1 }],
+        multiple: true,
+        valueKey: 'value'
+      })).toEqualTypeOf<[number[]]>()
+
+      // with string item
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: ['foo']
+      })).toEqualTypeOf<[string]>()
+
+      // with string item and multiple
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: ['foo'],
+        multiple: true
+      })).toEqualTypeOf<[string[]]>()
+
+      // with groups
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: [['foo']]
+      })).toEqualTypeOf<[string]>()
+
+      // with groups and multiple
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: [['foo']],
+        multiple: true
+      })).toEqualTypeOf<[string[]]>()
+
+      // with groups, multiple and mixed types
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: [['foo', { value: 1 }], [{ value: 'bar' }, 2]],
+        multiple: true
+      })).toEqualTypeOf<[(string | number | { value: string } | { value: number })[]]>()
+
+      // with groups, multiple, mixed types and valueKey
+      expectEmitPayloadType('update:modelValue', () => SelectMenu({
+        items: [['foo', { value: 1 }], [{ value: 'bar' }, 2]],
+        multiple: true,
+        valueKey: 'value'
+      })).toEqualTypeOf<[(string | number)[]]>()
+    })
   })
 })

test/utils/types.ts

@@ -0,0 +1,13 @@
+import { expectTypeOf } from 'vitest'
+import type { VNode } from 'vue'
+
+/**
+ * Expect the type of a component emit payload.
+ */
+export function expectEmitPayloadType<T extends VNode, E extends keyof Events<T>>(_event: E, _cb: () => T) {
+  return expectTypeOf<NonNullable<Events<T>[E]>>()
+}
+
+type Events<T> = T extends { __ctx?: { props: infer Props } } ? {
+  [K in keyof Props as K extends `on${infer E}${infer Rest}` ? `${Lowercase<E>}${Rest}` : never]: NonNullable<Props[K]> extends (...args: infer P) => any ? P : never
+} : never