fix: Allow selectedKey=null to clear value in HiddenSelect

packages/@react-aria/select/src/HiddenSelect.tsx

@@ -11,7 +11,7 @@
  */
 
 import {FocusableElement, RefObject} from '@react-types/shared';
-import React, {JSX, ReactNode, useRef} from 'react';
+import React, {JSX, ReactNode, useCallback, useRef} from 'react';
 import {selectData} from './useSelect';
 import {SelectState} from '@react-stately/select';
 import {useFormReset} from '@react-aria/utils';
@@ -75,6 +75,9 @@ export function useHiddenSelect<T>(props: AriaHiddenSelectOptions, state: Select
     focus: () => triggerRef.current?.focus()
   }, state, props.selectRef);
 
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  let onChange = useCallback((e: React.ChangeEvent<HTMLSelectElement> | React.FormEvent<HTMLSelectElement>) => state.setSelectedKey(e.currentTarget.value), [state.setSelectedKey]);
+
   // In Safari, the <select> cannot have `display: none` or `hidden` for autofill to work.
   // In Firefox, there must be a <label> to identify the <select> whereas other browsers
   // seem to identify it just by surrounding text.
@@ -99,8 +102,9 @@ export function useHiddenSelect<T>(props: AriaHiddenSelectOptions, state: Select
       disabled: isDisabled,
       required: validationBehavior === 'native' && isRequired,
       name,
-      value: state.selectedKey ?? undefined,
-      onChange: (e: React.ChangeEvent<HTMLSelectElement>) => state.setSelectedKey(e.target.value)
+      value: state.selectedKey ?? '',
+      onChange,
+      onInput: onChange
     }
   };
 }

packages/@react-spectrum/picker/test/Picker.test.js

@@ -1715,6 +1715,7 @@ describe('Picker', function () {
       expect(options.length).toBe(60);
       options.forEach((option, index) => index > 0 && expect(option).toHaveTextContent(states[index - 1].name));
 
+      fireEvent.input(hiddenSelect, {target: {value: 'CA'}});
       fireEvent.change(hiddenSelect, {target: {value: 'CA'}});
       expect(onSelectionChange).toHaveBeenCalledTimes(1);
       expect(onSelectionChange).toHaveBeenLastCalledWith('CA');

packages/react-aria-components/stories/Select.stories.tsx

@@ -10,7 +10,7 @@
  * governing permissions and limitations under the License.
  */
 
-import {Button, Collection, Label, ListBox, ListLayout, OverlayArrow, Popover, Select, SelectValue, Virtualizer} from 'react-aria-components';
+import {Button, Collection, FieldError, Form, Input, Label, ListBox, ListLayout, OverlayArrow, Popover, Select, SelectValue, TextField, Virtualizer} from 'react-aria-components';
 import {LoadingSpinner, MyListBoxItem} from './utils';
 import React from 'react';
 import styles from '../example/index.css';
@@ -174,3 +174,41 @@ AsyncVirtualizedCollectionRenderSelect.story = {
     delay: 50
   }
 };
+
+export const SelectSubmitExample = () => (
+  <Form>
+    <TextField
+      isRequired
+      autoComplete="username"
+      className={styles.textfieldExample}
+      name="username">
+      <Label>Username</Label>
+      <Input />
+      <FieldError className={styles.errorMessage} />
+    </TextField>
+    <Select isRequired autoComplete="organization" name="company">
+      <Label style={{display: 'block'}}>Company</Label>
+      <Button>
+        <SelectValue />
+        <span aria-hidden="true" style={{paddingLeft: 5}}>
+          ▼
+        </span>
+      </Button>
+      <Popover>
+        <OverlayArrow>
+          <svg height={12} width={12}>
+            <path d="M0 0,L6 6,L12 0" />
+          </svg>
+        </OverlayArrow>
+        <ListBox className={styles.menu}>
+          <MyListBoxItem>Adobe</MyListBoxItem>
+          <MyListBoxItem>Google</MyListBoxItem>
+          <MyListBoxItem>Microsoft</MyListBoxItem>
+        </ListBox>
+      </Popover>
+      <FieldError className={styles.errorMessage} />
+    </Select>
+    <Button type="submit">Submit</Button>
+    <Button type="reset">Reset</Button>
+  </Form>
+);

packages/react-aria-components/test/Select.test.js

@@ -11,7 +11,7 @@
  */
 
 import {act, pointerMap, render, within} from '@react-spectrum/test-utils-internal';
-import {Button, FieldError, Label, ListBox, ListBoxItem, Popover, Select, SelectContext, SelectStateContext, SelectValue, Text} from '../';
+import {Button, FieldError, Form, Label, ListBox, ListBoxItem, Popover, Select, SelectContext, SelectStateContext, SelectValue, Text} from '../';
 import React from 'react';
 import {User} from '@react-aria/test-utils';
 import userEvent from '@testing-library/user-event';
@@ -413,4 +413,44 @@ describe('Select', () => {
     let text = popover.querySelector('.react-aria-Text');
     expect(text).not.toHaveAttribute('id');
   });
+
+  it('should not submit if required and selectedKey is null', async () => {
+    const onSubmit = jest.fn().mockImplementation(e => e.preventDefault());
+
+    function Test() {
+      const [selectedKey, setSelectedKey] = React.useState(null);
+      return (
+        <Form onSubmit={onSubmit}>
+          <TestSelect
+            isRequired
+            name="select"
+            selectedKey={selectedKey}
+            onSelectionChange={setSelectedKey} />
+          <Button data-testid="submit" type="submit">
+            Submit
+          </Button>
+          <Button data-testid="clear" onPress={() => setSelectedKey(null)}>
+            Reset
+          </Button>
+        </Form>
+      );
+    }
+
+    const {getByTestId} = render(<Test />);
+    const wrapper = getByTestId('select');
+    const selectTester = testUtilUser.createTester('Select', {root: wrapper});
+    const trigger = selectTester.trigger;
+    const submit = getByTestId('submit');
+
+    expect(trigger).toHaveTextContent('Select an item');
+    await selectTester.selectOption({option: 'Cat'});
+    expect(trigger).toHaveTextContent('Cat');
+    await user.click(submit);
+    expect(onSubmit).toHaveBeenCalledTimes(1);
+    await user.click(getByTestId('clear'));
+    expect(trigger).toHaveTextContent('Select an item');
+    await user.click(submit);
+    expect(onSubmit).toHaveBeenCalledTimes(1);
+    expect(document.querySelector('[name=select]').value).toBe('');
+  });
 });