fix: clear DateInput when controlled value prop becomes undefined

When a controlled DateInput had its value prop change from a date string
to undefined, the input visually retained the old date. This adds reset
logic in componentDidUpdate to clear both internal state and the DOM
element when the value transitions from truthy to falsy.

OWNER-221

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: scottpchow23

src/components/Input/DateInput.js

@@ -248,6 +248,13 @@ export default class DateInput extends React.Component {
   }
 
   componentDidUpdate(prevProps, prevState) {
+    if (prevProps.value && !this.props.value) {
+      this.setState({ value: '' });
+      if (this.inputEl) {
+        this.inputEl.value = '';
+        this.inputEl.setAttribute('value', '');
+      }
+    }
     this.setInputValue();
     if (this.props.onClose && this.state.open !== prevState.open && !this.state.open) {
       const value = this.props.value !== undefined ? this.props.value : this.state.value;

src/components/Input/DateInput.spec.js

@@ -560,6 +560,28 @@ describe('<DateInput />', () => {
     });
   });
 
+  describe('controlled value', () => {
+    it('should clear displayed value when value prop changes to undefined', () => {
+      const component = mount(<DateInput value="1/1/2025" />);
+      const input = component.find('input');
+      assert.equal(input.getDOMNode().value, '1/1/2025');
+
+      component.setProps({ value: undefined });
+      component.update();
+      assert.equal(input.getDOMNode().value, '');
+    });
+
+    it('should clear displayed value when value prop changes to empty string', () => {
+      const component = mount(<DateInput value="1/1/2025" />);
+      const input = component.find('input');
+      assert.equal(input.getDOMNode().value, '1/1/2025');
+
+      component.setProps({ value: '' });
+      component.update();
+      assert.equal(input.getDOMNode().value, '');
+    });
+  });
+
   describe('accessibility', () => {
     it('should contain screen reader only label for buttons', () => {
       const component = mount(<DateInput />);