fix(VCombobox): filter matching items when opening first time (#21900)

packages/vuetify/src/components/VCombobox/VCombobox.tsx

@@ -72,7 +72,7 @@ export const makeVComboboxProps = propsFactory({
   delimiters: Array as PropType<readonly string[]>,
 
   ...makeFilterProps({ filterKeys: ['title'] }),
-  ...makeSelectProps({ hideNoData: true, returnObject: true }),
+  ...makeSelectProps({ hideNoData: false, returnObject: true }),
   ...omit(makeVTextFieldProps({
     modelValue: null,
     role: 'combobox',
@@ -127,6 +127,7 @@ export const VCombobox = genericComponent<new <
     const isFocused = shallowRef(false)
     const isPristine = shallowRef(true)
     const listHasFocus = shallowRef(false)
+    const showAllItemsForNoMatch = shallowRef(false)
     const vMenuRef = ref<VMenu>()
     const vVirtualScrollRef = ref<VVirtualScroll>()
     const selectionIndex = shallowRef(-1)
@@ -194,6 +195,9 @@ export const VCombobox = genericComponent<new <
       if (props.hideSelected) {
         return filteredItems.value.filter(filteredItem => !model.value.some(s => s.value === filteredItem.value))
       }
+      if (filteredItems.value.length === 0 && showAllItemsForNoMatch.value) {
+        return items.value
+      }
       return filteredItems.value
     })
 
@@ -214,6 +218,7 @@ export const VCombobox = genericComponent<new <
     const label = toRef(() => menu.value ? props.closeText : props.openText)
 
     watch(_search, value => {
+      showAllItemsForNoMatch.value = false
       if (cleared) {
         // wait for clear to finish, VTextField sets _search to null
         // then search computed triggers and updates _search to ''
@@ -222,6 +227,7 @@ export const VCombobox = genericComponent<new <
         menu.value = true
       }
 
+      isPristine.value = !value
       emit('update:search', value)
     })
 
@@ -439,16 +445,22 @@ export const VCombobox = genericComponent<new <
       }
     })
 
-    watch(menu, () => {
-      if (!props.hideSelected && menu.value && model.value.length) {
+    watch(menu, val => {
+      if (!props.hideSelected && val && model.value.length) {
         const index = displayItems.value.findIndex(
           item => model.value.some(s => (props.valueComparator || deepEqual)(s.value, item.value))
         )
         IN_BROWSER && window.requestAnimationFrame(() => {
           index >= 0 && vVirtualScrollRef.value?.scrollToIndex(index)
         })
       }
-    })
+
+      if (val && search.value && filteredItems.value.length === 0) {
+        showAllItemsForNoMatch.value = true
+      }
+
+      isPristine.value = !search.value
+    }, { immediate: true })
 
     watch(() => props.items, (newVal, oldVal) => {
       if (menu.value) return
@@ -536,7 +548,6 @@ export const VCombobox = genericComponent<new <
                       { !displayItems.value.length && !props.hideNoData && (slots['no-data']?.() ?? (
                         <VListItem key="no-data" title={ t(props.noDataText) } />
                       ))}
-
                       <VVirtualScroll ref={ vVirtualScrollRef } renderless items={ displayItems.value } itemKey="value">
                         { ({ item, index, itemRef }) => {
                           const itemProps = mergeProps(item.props, {
@@ -692,7 +703,7 @@ export const VCombobox = genericComponent<new <
             'append-inner': (...args) => (
               <>
                 { slots['append-inner']?.(...args) }
-                { (!props.hideNoData || props.items.length) && props.menuIcon ? (
+                { props.menuIcon ? (
                   <VIcon
                     class="v-combobox__menu-icon"
                     color={ vTextFieldRef.value?.fieldIconColor }

packages/vuetify/src/components/VCombobox/__tests__/VCombobox.spec.browser.tsx

@@ -771,6 +771,41 @@ describe('VCombobox', () => {
     expect(model.value).toEqual(expected)
   })
 
+  it('should show only matching items when reopening the menu', async () => {
+    const { element } = render(() => (
+      <VCombobox items={['California', 'Colorado', 'Florida', 'Georgia', 'Texas', 'Wyoming']} />
+    ))
+
+    await userEvent.click(element)
+    await userEvent.keyboard('c')
+    await expect(screen.findAllByRole('option')).resolves.toHaveLength(2)
+    await userEvent.keyboard('al')
+    await expect(screen.findAllByRole('option')).resolves.toHaveLength(1)
+    await userEvent.click(document.body)
+    await expect.poll(() => screen.queryAllByRole('option')).toHaveLength(0)
+    await userEvent.click(element)
+    await expect.poll(() => screen.queryAllByRole('option')).toHaveLength(1)
+  })
+
+  it('should show only matching items when opening for the first time', async () => {
+    const model = ref('flor')
+    const { element } = render(() => (
+      <VCombobox
+        v-model={ model.value }
+        items={['California', 'Colorado', 'Florida', 'Georgia', 'Texas', 'Wyoming']}
+      />
+    ))
+
+    await userEvent.click(element)
+    expect(screen.getAllByRole('option')).toHaveLength(1)
+    await userEvent.click(document.body)
+    await expect.poll(() => screen.queryAllByRole('option')).toHaveLength(0)
+
+    // expect same behavior when re-opening the menu
+    await userEvent.click(element)
+    await expect.poll(() => screen.queryAllByRole('option')).toHaveLength(1)
+  })
+
   describe('Showcase', () => {
     generate({ stories })
   })