Fix tag value reappearing after clearing and pressing Done

lib/widgets/nsi_tag_value_field.dart

@@ -132,7 +132,14 @@ class _NSITagValueFieldState extends State<NSITagValueField> {
           onChanged: (value) {
             widget.onChanged(value);
           },
-          onSubmitted: (_) => onFieldSubmitted(),
+          onSubmitted: (_) {
+            // Only auto-complete when there's text to match against.
+            // Otherwise, pressing Done on an empty field would auto-select
+            // the first suggestion, preventing users from clearing values.
+            if (controller.text.isNotEmpty) {
+              onFieldSubmitted();
+            }
+          },
         );
       },
       optionsViewBuilder: (

test/widgets/nsi_tag_value_field_test.dart

@@ -0,0 +1,177 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+/// Tests for the tag value field clearing bug and fix.
+///
+/// Root cause: RawAutocomplete.onFieldSubmitted auto-selects the first option
+/// when called, and NSITagValueField's optionsBuilder returns ALL suggestions
+/// when the text is empty. So pressing "Done" on the keyboard with an empty
+/// field auto-selects the first NSI suggestion, making the value "pop back in".
+void main() {
+  // Helper to build a RawAutocomplete widget tree that mirrors NSITagValueField
+  Widget buildAutocompleteField({
+    required TextEditingController controller,
+    required FocusNode focusNode,
+    required List<String> suggestions,
+    required ValueChanged<String> onChanged,
+    required ValueChanged<String> onSelected,
+    required bool guardOnSubmitted,
+  }) {
+    return MaterialApp(
+      home: Scaffold(
+        body: Padding(
+          padding: const EdgeInsets.all(16),
+          child: RawAutocomplete<String>(
+            textEditingController: controller,
+            focusNode: focusNode,
+            optionsBuilder: (TextEditingValue textEditingValue) {
+              if (suggestions.isEmpty) {
+                return const Iterable<String>.empty();
+              }
+              if (textEditingValue.text.isEmpty) return suggestions;
+              return suggestions
+                  .where((s) => s.contains(textEditingValue.text));
+            },
+            onSelected: (String selection) => onSelected(selection),
+            fieldViewBuilder:
+                (context, controller, focusNode, onFieldSubmitted) {
+              return TextField(
+                controller: controller,
+                focusNode: focusNode,
+                onChanged: onChanged,
+                onSubmitted: guardOnSubmitted
+                    ? (_) {
+                        if (controller.text.isNotEmpty) {
+                          onFieldSubmitted();
+                        }
+                      }
+                    : (_) => onFieldSubmitted(),
+              );
+            },
+            optionsViewBuilder: (context, onSelected, options) {
+              return Align(
+                alignment: Alignment.topLeft,
+                child: Material(
+                  child: SizedBox(
+                    height: 200,
+                    child: ListView(
+                      children: options
+                          .map((o) => ListTile(
+                                title: Text(o),
+                                onTap: () => onSelected(o),
+                              ))
+                          .toList(),
+                    ),
+                  ),
+                ),
+              );
+            },
+          ),
+        ),
+      ),
+    );
+  }
+
+  group('NSITagValueField onSubmitted behavior', () {
+    testWidgets(
+        'unguarded onFieldSubmitted auto-selects first suggestion on empty submit',
+        (tester) async {
+      String reportedValue = 'Hikvision';
+      final controller = TextEditingController(text: 'Hikvision');
+      final focusNode = FocusNode();
+
+      await tester.pumpWidget(buildAutocompleteField(
+        controller: controller,
+        focusNode: focusNode,
+        suggestions: ['Axis', 'Dahua', 'Hikvision'],
+        onChanged: (v) => reportedValue = v,
+        onSelected: (v) => reportedValue = v,
+        guardOnSubmitted: false, // old behavior
+      ));
+
+      await tester.tap(find.byType(TextField));
+      await tester.pump();
+
+      // Clear the field
+      await tester.enterText(find.byType(TextField), '');
+      await tester.pump();
+      expect(controller.text, equals(''));
+
+      // Press "Done" on the keyboard
+      await tester.testTextInput.receiveAction(TextInputAction.done);
+      await tester.pump();
+
+      // Demonstrates the bug: first suggestion ('Axis') is auto-selected
+      expect(controller.text, equals('Axis'),
+          reason: 'Unguarded onFieldSubmitted auto-selects first suggestion');
+    });
+
+    testWidgets(
+        'guarded onFieldSubmitted keeps field empty on submit',
+        (tester) async {
+      String reportedValue = 'Hikvision';
+      final controller = TextEditingController(text: 'Hikvision');
+      final focusNode = FocusNode();
+
+      await tester.pumpWidget(buildAutocompleteField(
+        controller: controller,
+        focusNode: focusNode,
+        suggestions: ['Axis', 'Dahua', 'Hikvision'],
+        onChanged: (v) => reportedValue = v,
+        onSelected: (v) => reportedValue = v,
+        guardOnSubmitted: true, // fixed behavior
+      ));
+
+      await tester.tap(find.byType(TextField));
+      await tester.pump();
+
+      // Clear the field
+      await tester.enterText(find.byType(TextField), '');
+      await tester.pump();
+      expect(controller.text, equals(''));
+      expect(reportedValue, equals(''));
+
+      // Press "Done" on the keyboard
+      await tester.testTextInput.receiveAction(TextInputAction.done);
+      await tester.pump();
+
+      // Field stays empty
+      expect(controller.text, equals(''),
+          reason: 'Field should stay empty after pressing Done');
+      expect(reportedValue, equals(''),
+          reason: 'Parent should not receive a new value');
+    });
+
+    testWidgets(
+        'guarded onFieldSubmitted still auto-completes when text is present',
+        (tester) async {
+      String reportedValue = '';
+      final controller = TextEditingController();
+      final focusNode = FocusNode();
+
+      await tester.pumpWidget(buildAutocompleteField(
+        controller: controller,
+        focusNode: focusNode,
+        suggestions: ['Axis', 'Dahua', 'Hikvision'],
+        onChanged: (v) => reportedValue = v,
+        onSelected: (v) => reportedValue = v,
+        guardOnSubmitted: true, // fixed behavior
+      ));
+
+      await tester.tap(find.byType(TextField));
+      await tester.pump();
+
+      // Type a partial match
+      await tester.enterText(find.byType(TextField), 'Axi');
+      await tester.pump();
+
+      // Press "Done" → should auto-complete to 'Axis'
+      await tester.testTextInput.receiveAction(TextInputAction.done);
+      await tester.pump();
+
+      expect(controller.text, equals('Axis'),
+          reason: 'Should auto-complete partial text to first matching suggestion');
+      expect(reportedValue, equals('Axis'));
+    });
+  });
+}