Let CupertinoTextField's clear button also call onChanged (#29474)

packages/flutter/lib/src/cupertino/text_field.dart

@@ -660,9 +660,14 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
         } else if (_showClearButton(text)) {
           rowChildren.add(
             GestureDetector(
-              onTap: widget.enabled ?? true
-                  ? () => _effectiveController.clear()
-                  : null,
+              onTap: widget.enabled ?? true ? () {
+                // Special handle onChanged for ClearButton
+                // Also call onChanged when the clear button is tapped.
+                final bool textChanged = _effectiveController.text.isNotEmpty;
+                _effectiveController.clear();
+                if (widget.onChanged != null && textChanged)
+                  widget.onChanged(_effectiveController.text);
+              } : null,
               child: const Padding(
                 padding: EdgeInsets.symmetric(horizontal: 6.0),
                 child: Icon(

packages/flutter/test/cupertino/text_field_test.dart

@@ -749,6 +749,36 @@ void main() {
     },
   );
 
+  testWidgets(
+    'tapping clear button also calls onChanged when text not empty',
+        (WidgetTester tester) async {
+      String value = 'text entry';
+      final TextEditingController controller = TextEditingController();
+      await tester.pumpWidget(
+        CupertinoApp(
+          home: Center(
+            child: CupertinoTextField(
+              controller: controller,
+              placeholder: 'placeholder',
+              onChanged: (String newValue) => value = newValue,
+              clearButtonMode: OverlayVisibilityMode.always,
+            ),
+          ),
+        ),
+      );
+
+      controller.text = value;
+      await tester.pump();
+
+      await tester.tap(find.byIcon(CupertinoIcons.clear_thick_circled));
+      await tester.pump();
+
+      expect(controller.text, isEmpty);
+      expect(find.text('text entry'), findsNothing);
+      expect(value, isEmpty);
+    },
+  );
+
   testWidgets(
     'clear button yields precedence to suffix',
     (WidgetTester tester) async {