Fire user’s onChange handler when we update the combobox input value internally

packages/@headlessui-react/CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix `<Popover.Button as={Fragment} />` crash ([#1889](https://github.com/tailwindlabs/headlessui/pull/1889))
 - Expose `close` function for `Menu` and `Menu.Item` components ([#1897](https://github.com/tailwindlabs/headlessui/pull/1897))
 - Fix `useOutsideClick`, add improvements for ShadowDOM ([#1914](https://github.com/tailwindlabs/headlessui/pull/1914))
+- Fire `<Combobox.Input>`'s `onChange` handler when changing the value internally ([#1916](https://github.com/tailwindlabs/headlessui/pull/1916))
 
 ### Added
 

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

@@ -2851,6 +2851,56 @@ describe('Keyboard interactions', () => {
           expect(getComboboxInput()?.value).toBe('option-b')
         })
       )
+
+      it(
+        'The onChange handler is fired when the input value is changed internally',
+        suppressConsoleLogs(async () => {
+          let currentSearchQuery: string = ''
+
+          render(
+            <Combobox value={null} onChange={console.log}>
+              <Combobox.Input
+                onChange={(event) => {
+                  currentSearchQuery = event.target.value
+                }}
+              />
+              <Combobox.Button>Trigger</Combobox.Button>
+              <Combobox.Options>
+                <Combobox.Option value="option-a">Option A</Combobox.Option>
+                <Combobox.Option value="option-b">Option B</Combobox.Option>
+                <Combobox.Option value="option-c">Option C</Combobox.Option>
+              </Combobox.Options>
+            </Combobox>
+          )
+
+          // Open combobox
+          await click(getComboboxButton())
+
+          // Verify that the current search query is empty
+          expect(currentSearchQuery).toBe('')
+
+          // Look for "Option C"
+          await type(word('Option C'), getComboboxInput())
+
+          // The input should be updated
+          expect(getComboboxInput()?.value).toBe('Option C')
+
+          // The current search query should reflect the input value
+          expect(currentSearchQuery).toBe('Option C')
+
+          // Close combobox
+          await press(Keys.Escape)
+
+          // The input should be empty
+          expect(getComboboxInput()?.value).toBe('')
+
+          // The current search query should be empty like the input
+          expect(currentSearchQuery).toBe('')
+
+          // The combobox should be closed
+          assertComboboxList({ state: ComboboxState.InvisibleUnmounted })
+        })
+      )
     })
 
     describe('`ArrowDown` key', () => {
@@ -5501,7 +5551,7 @@ describe('Form compatibility', () => {
           }}
         >
           <Combobox value={value} onChange={setValue} name="delivery">
-            <Combobox.Input onChange={console.log} />
+            <Combobox.Input onChange={NOOP} />
             <Combobox.Button>Trigger</Combobox.Button>
             <Combobox.Label>Pizza Delivery</Combobox.Label>
             <Combobox.Options>

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

@@ -666,6 +666,33 @@ let Input = forwardRefWithAs(function Input<
   let id = `headlessui-combobox-input-${useId()}`
   let d = useDisposables()
 
+  let shouldIgnoreOpenOnChange = false
+  function updateInputAndNotify(newValue: string) {
+    let input = data.inputRef.current
+    if (!input) {
+      return
+    }
+
+    // The value is already the same, so we can bail out early
+    if (input.value === newValue) {
+      return
+    }
+
+    // Skip React's value setting which causes the input event to not be fired because it de-dupes input/change events
+    let descriptor = Object.getOwnPropertyDescriptor(input.constructor.prototype, 'value')
+    descriptor?.set?.call(input, newValue)
+
+    // Fire an input event which causes the browser to trigger the user's `onChange` handler.
+    // We have to prevent the combobox from opening when this happens. Since these events
+    // fire synchronously `shouldIgnoreOpenOnChange` will be correct during `handleChange`
+    shouldIgnoreOpenOnChange = true
+    input.dispatchEvent(new Event('input', { bubbles: true }))
+
+    // Now we can inform react that the input value has changed
+    input.value = newValue
+    shouldIgnoreOpenOnChange = false
+  }
+
   let currentValue = useMemo(() => {
     if (typeof displayValue === 'function') {
       return displayValue(data.value as unknown as TType) ?? ''
@@ -682,7 +709,7 @@ let Input = forwardRefWithAs(function Input<
     ([currentValue, state], [oldCurrentValue, oldState]) => {
       if (!data.inputRef.current) return
       if (oldState === ComboboxState.Open && state === ComboboxState.Closed) {
-        data.inputRef.current.value = currentValue
+        updateInputAndNotify(currentValue)
       } else if (currentValue !== oldCurrentValue) {
         data.inputRef.current.value = currentValue
       }
@@ -787,7 +814,9 @@ let Input = forwardRefWithAs(function Input<
   })
 
   let handleChange = useEvent((event: React.ChangeEvent<HTMLInputElement>) => {
-    actions.openCombobox()
+    if (!shouldIgnoreOpenOnChange) {
+      actions.openCombobox()
+    }
     onChange?.(event)
   })
 

packages/@headlessui-vue/CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Expose `close` function for `Menu` and `MenuItem` components ([#1897](https://github.com/tailwindlabs/headlessui/pull/1897))
 - Fix `useOutsideClick`, add improvements for ShadowDOM ([#1914](https://github.com/tailwindlabs/headlessui/pull/1914))
 - Prevent default slot warning when using a component for `as` prop ([#1915](https://github.com/tailwindlabs/headlessui/pull/1915))
+- Fire `<ComboboxInput>`'s `@change` handler when changing the value internally ([#1916](https://github.com/tailwindlabs/headlessui/pull/1916))
 
 ## [1.7.3] - 2022-09-30
 

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

@@ -2931,6 +2931,60 @@ describe('Keyboard interactions', () => {
           expect(getComboboxInput()?.value).toBe('option-b')
         })
       )
+
+      it(
+        'The onChange handler is fired when the input value is changed internally',
+        suppressConsoleLogs(async () => {
+          let currentSearchQuery: string = ''
+
+          renderTemplate({
+            template: html`
+              <Combobox v-model="value">
+                <ComboboxInput @change="onChange" />
+                <ComboboxButton>Trigger</ComboboxButton>
+                <ComboboxOptions>
+                  <ComboboxOption value="option-a">Option A</ComboboxOption>
+                  <ComboboxOption value="option-b">Option B</ComboboxOption>
+                  <ComboboxOption value="option-c">Option C</ComboboxOption>
+                </ComboboxOptions>
+              </Combobox>
+            `,
+            setup: () => ({
+              value: ref(null),
+              onChange: (evt: InputEvent & { target: HTMLInputElement }) => {
+                currentSearchQuery = evt.target.value
+              },
+            }),
+          })
+
+          // Open combobox
+          await click(getComboboxButton())
+
+          // Verify that the current search query is empty
+          expect(currentSearchQuery).toBe('')
+
+          // Look for "Option C"
+          await type(word('Option C'), getComboboxInput())
+
+          // The input should be updated
+          expect(getComboboxInput()?.value).toBe('Option C')
+
+          // The current search query should reflect the input value
+          expect(currentSearchQuery).toBe('Option C')
+
+          // Close combobox
+          await press(Keys.Escape)
+
+          // The input should be empty
+          expect(getComboboxInput()?.value).toBe('')
+
+          // The current search query should be empty like the input
+          expect(currentSearchQuery).toBe('')
+
+          // The combobox should be closed
+          assertComboboxList({ state: ComboboxState.InvisibleUnmounted })
+        })
+      )
     })
 
     describe('`ArrowDown` key', () => {

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

@@ -632,6 +632,23 @@ export let ComboboxInput = defineComponent({
     // Workaround Vue bug where watching [ref(undefined)] is not fired immediately even when value is true
     const __fixVueImmediateWatchBug__ = ref('')
 
+    let shouldIgnoreOpenOnChange = false
+    function updateInputAndNotify(currentValue: string) {
+      let input = dom(api.inputRef)
+      if (!input) {
+        return
+      }
+
+      input.value = currentValue
+
+      // Fire an input event which causes the browser to trigger the user's `onChange` handler.
+      // We have to prevent the combobox from opening when this happens. Since these events
+      // fire synchronously `shouldIgnoreOpenOnChange` will be correct during `handleChange`
+      shouldIgnoreOpenOnChange = true
+      input.dispatchEvent(new Event('input', { bubbles: true }))
+      shouldIgnoreOpenOnChange = false
+    }
+
     onMounted(() => {
       watch(
         [api.value, __fixVueImmediateWatchBug__],
@@ -650,7 +667,7 @@ export let ComboboxInput = defineComponent({
           let input = dom(api.inputRef)
           if (!input) return
           if (oldState === ComboboxStates.Open && state === ComboboxStates.Closed) {
-            input.value = currentValue
+            updateInputAndNotify(currentValue)
           } else if (currentValue !== oldCurrentValue) {
             input.value = currentValue
           }
@@ -756,7 +773,9 @@ export let ComboboxInput = defineComponent({
     }
 
     function handleInput(event: Event & { target: HTMLInputElement }) {
-      api.openCombobox()
+      if (!shouldIgnoreOpenOnChange) {
+        api.openCombobox()
+      }
       emit('change', event)
     }