fix(field): recompute isDirty when value matches initial

Author: majumdersubhanu

lib/src/form_builder_field.dart

@@ -185,7 +185,7 @@ class FormBuilderFieldState<F extends FormBuilderField<T>, T>
 
   void _informFormForFieldChange() {
     if (_formBuilderState != null) {
-      _dirty = true;
+      _dirty = value != initialValue;
       if (enabled || readOnly) {
         _formBuilderState!.setInternalFieldValue<T>(widget.name, value);
         return;

test/src/form_builder_field_test.dart

@@ -419,6 +419,27 @@ void main() {
           expect(textFieldKey.currentState?.isDirty, true);
         },
       );
+      testWidgets('Should not dirty when value returns to initial by user', (
+        tester,
+      ) async {
+        const textFieldName = 'text';
+        final textFieldKey = GlobalKey<FormBuilderFieldState>();
+        final testWidget = FormBuilderTextField(
+          name: textFieldName,
+          key: textFieldKey,
+          initialValue: 'hi',
+        );
+        await tester.pumpWidget(buildTestableFieldWidget(testWidget));
+
+        final widgetFinder = find.byWidget(testWidget);
+        await tester.enterText(widgetFinder, 'test');
+        await tester.pumpAndSettle();
+        expect(textFieldKey.currentState?.isDirty, true);
+
+        await tester.enterText(widgetFinder, 'hi');
+        await tester.pumpAndSettle();
+        expect(textFieldKey.currentState?.isDirty, false);
+      });
       testWidgets('Should not dirty when reset field value', (tester) async {
         const textFieldName = 'text';
         final textFieldKey = GlobalKey<FormBuilderFieldState>();
@@ -481,6 +502,37 @@ void main() {
       });
     });
     group('reset -', () {
+      testWidgets(
+        'Should avoid reset recursion when value returns to initial in onChanged',
+        (tester) async {
+          const textFieldName = 'text';
+          final textFieldKey = GlobalKey<FormBuilderFieldState>();
+          var onChangedCalls = 0;
+          final testWidget = FormBuilderTextField(
+            name: textFieldName,
+            key: textFieldKey,
+            initialValue: 'hi',
+            onChanged: (value) {
+              onChangedCalls++;
+              final state = textFieldKey.currentState;
+              if (value == state?.initialValue && state?.isDirty == true) {
+                state?.reset();
+              }
+            },
+          );
+          await tester.pumpWidget(buildTestableFieldWidget(testWidget));
+
+          final widgetFinder = find.byWidget(testWidget);
+          await tester.enterText(widgetFinder, 'test');
+          await tester.pumpAndSettle();
+          await tester.enterText(widgetFinder, 'hi');
+          await tester.pumpAndSettle();
+
+          expect(tester.takeException(), isNull);
+          expect(textFieldKey.currentState?.isDirty, false);
+          expect(onChangedCalls, equals(2));
+        },
+      );
       testWidgets('Should reset to null when call reset', (tester) async {
         const textFieldName = 'text';
         final textFieldKey = GlobalKey<FormBuilderFieldState>();

test/src/form_builder_test.dart

@@ -444,6 +444,27 @@ void main() {
 
       expect(formKey.currentState?.isDirty, true);
     });
+    testWidgets('Should not dirty when value returns to initial by user', (
+      tester,
+    ) async {
+      const textFieldName = 'text';
+      final testWidget = FormBuilderTextField(name: textFieldName);
+      await tester.pumpWidget(
+        buildTestableFieldWidget(
+          testWidget,
+          initialValue: {textFieldName: 'hi'},
+        ),
+      );
+
+      final widgetFinder = find.byWidget(testWidget);
+      await tester.enterText(widgetFinder, 'test');
+      await tester.pumpAndSettle();
+      expect(formKey.currentState?.isDirty, true);
+
+      await tester.enterText(widgetFinder, 'hi');
+      await tester.pumpAndSettle();
+      expect(formKey.currentState?.isDirty, false);
+    });
     testWidgets('Should dirty when update field with initial value by method', (
       tester,
     ) async {