ensure blurring the Combobox.Input component closes the Combobox

packages/@headlessui-react/src/components/combobox/combobox.test.tsx

@@ -6,6 +6,7 @@ import { mockingConsoleLogs, suppressConsoleLogs } from '../../test-utils/suppre
 import {
   click,
   focus,
+  blur,
   mouseMove,
   mouseLeave,
   press,
@@ -449,6 +450,43 @@ describe('Rendering', () => {
         )
       })
     )
+
+    it(
+      'should close the Combobox when the input is blurred',
+      suppressConsoleLogs(async () => {
+        let data = [
+          { id: 1, name: 'alice', label: 'Alice' },
+          { id: 2, name: 'bob', label: 'Bob' },
+          { id: 3, name: 'charlie', label: 'Charlie' },
+        ]
+
+        render(
+          <Combobox name="assignee" by="id">
+            <Combobox.Input onChange={NOOP} />
+            <Combobox.Button />
+            <Combobox.Options>
+              {data.map((person) => (
+                <Combobox.Option key={person.id} value={person}>
+                  {person.label}
+                </Combobox.Option>
+              ))}
+            </Combobox.Options>
+          </Combobox>
+        )
+
+        // Open the combobox
+        await click(getComboboxButton())
+
+        // Verify it is open
+        assertComboboxList({ state: ComboboxState.Visible })
+
+        // Close the combobox
+        await blur(getComboboxInput())
+
+        // Verify it is closed
+        assertComboboxList({ state: ComboboxState.InvisibleUnmounted })
+      })
+    )
   })
 
   describe('Combobox.Input', () => {

packages/@headlessui-react/src/components/combobox/combobox.tsx

@@ -13,6 +13,7 @@ import React, {
   ElementType,
   KeyboardEvent as ReactKeyboardEvent,
   MouseEvent as ReactMouseEvent,
+  FocusEvent as ReactFocusEvent,
   MutableRefObject,
   Ref,
 } from 'react'
@@ -1019,8 +1020,33 @@ function InputFn<
     actions.openCombobox()
   })
 
-  let handleBlur = useEvent(() => {
+  let handleBlur = useEvent((event: ReactFocusEvent) => {
     isTyping.current = false
+
+    // Focus is moved into the list, we don't want to close yet.
+    if (data.optionsRef.current?.contains(event.relatedTarget)) {
+      return
+    }
+
+    if (data.buttonRef.current?.contains(event.relatedTarget)) {
+      return
+    }
+
+    if (data.comboboxState !== ComboboxState.Open) return
+    event.preventDefault()
+
+    if (data.nullable && data.mode === ValueMode.Single) {
+      // We want to clear the value when the user presses escape if and only if the current
+      // value is not set (aka, they didn't select anything yet, or they cleared the input which
+      // caused the value to be set to `null`). If the current value is set, then we want to
+      // fallback to that value when we press escape (this part is handled in the watcher that
+      // syncs the value with the input field again).
+      if (data.value === null) {
+        clear()
+      }
+    }
+
+    return actions.closeCombobox()
   })
 
   // TODO: Verify this. The spec says that, for the input/combobox, the label is the labelling element when present

packages/@headlessui-react/src/test-utils/interactions.ts

@@ -295,6 +295,24 @@ export async function focus(element: Document | Element | Window | Node | null)
     throw err
   }
 }
+
+export async function blur(element: Document | Element | Window | Node | null) {
+  try {
+    if (element === null) return expect(element).not.toBe(null)
+
+    if (element instanceof HTMLElement) {
+      element.blur()
+    } else {
+      fireEvent.blur(element)
+    }
+
+    await new Promise(nextFrame)
+  } catch (err) {
+    if (err instanceof Error) Error.captureStackTrace(err, blur)
+    throw err
+  }
+}
+
 export async function mouseEnter(element: Document | Element | Window | null) {
   try {
     if (element === null) return expect(element).not.toBe(null)

packages/@headlessui-vue/src/components/combobox/combobox.test.ts

@@ -12,6 +12,7 @@ import { suppressConsoleLogs } from '../../test-utils/suppress-console-logs'
 import {
   click,
   focus,
+  blur,
   mouseMove,
   mouseLeave,
   press,
@@ -500,6 +501,44 @@ describe('Rendering', () => {
         })
       })
     )
+
+    it(
+      'should close the Combobox when the input is blurred',
+      suppressConsoleLogs(async () => {
+        let data = [
+          { id: 1, name: 'alice', label: 'Alice' },
+          { id: 2, name: 'bob', label: 'Bob' },
+          { id: 3, name: 'charlie', label: 'Charlie' },
+        ]
+
+        renderTemplate({
+          template: html`
+            <Combobox name="assignee" by="id">
+              <ComboboxInput />
+              <ComboboxButton />
+              <ComboboxOptions>
+                <ComboboxOption v-for="person in data" :key="person.id" :value="person">
+                  {{ person.label }}
+                </ComboboxOption>
+              <ComboboxOptions>
+            </Combobox>
+          `,
+          setup: () => ({ data }),
+        })
+
+        // Open the combobox
+        await click(getComboboxButton())
+
+        // Verify it is open
+        assertComboboxList({ state: ComboboxState.Visible })
+
+        // Close the combobox
+        await blur(getComboboxInput())
+
+        // Verify it is closed
+        assertComboboxList({ state: ComboboxState.InvisibleUnmounted })
+      })
+    )
   })
 
   describe('ComboboxInput', () => {

packages/@headlessui-vue/src/components/combobox/combobox.ts

@@ -981,8 +981,39 @@ export let ComboboxInput = defineComponent({
       api.openCombobox()
     }
 
-    function handleBlur() {
+    function handleBlur(event: FocusEvent) {
       isTyping.value = false
+
+      // Focus is moved into the list, we don't want to close yet.
+      if (
+        event.relatedTarget instanceof Node &&
+        dom(api.optionsRef)?.contains(event.relatedTarget)
+      ) {
+        return
+      }
+
+      if (
+        event.relatedTarget instanceof Node &&
+        dom(api.buttonRef)?.contains(event.relatedTarget)
+      ) {
+        return
+      }
+
+      if (api.comboboxState.value !== ComboboxStates.Open) return
+      event.preventDefault()
+
+      if (api.nullable.value && api.mode.value === ValueMode.Single) {
+        // We want to clear the value when the user presses escape if and only if the current
+        // value is not set (aka, they didn't select anything yet, or they cleared the input which
+        // caused the value to be set to `null`). If the current value is set, then we want to
+        // fallback to that value when we press escape (this part is handled in the watcher that
+        // syncs the value with the input field again).
+        if (api.value.value === null) {
+          clear()
+        }
+      }
+
+      return api.closeCombobox()
     }
 
     let defaultValue = computed(() => {

packages/@headlessui-vue/src/test-utils/interactions.ts

@@ -293,6 +293,24 @@ export async function focus(element: Document | Element | Window | Node | null)
     throw err
   }
 }
+
+export async function blur(element: Document | Element | Window | Node | null) {
+  try {
+    if (element === null) return expect(element).not.toBe(null)
+
+    if (element instanceof HTMLElement) {
+      element.blur()
+    } else {
+      fireEvent.blur(element)
+    }
+
+    await new Promise(nextFrame)
+  } catch (err) {
+    if (err instanceof Error) Error.captureStackTrace(err, blur)
+    throw err
+  }
+}
+
 export async function mouseEnter(element: Document | Element | Window | null) {
   try {
     if (element === null) return expect(element).not.toBe(null)