Enable credential autofill for signup and login (#56)

docs/ux/auth-journeys.md

@@ -149,3 +149,66 @@ text uses a normal text node to remain exposed to assistive technology.
 Delivered in [PR #13](https://git.sendico.io/tech/sxchnge/pulls/13), branch
 `onboarding-12`. The final browser accessibility tree exposes the recipient text,
 demo status, status heading and recovery actions. PR is open for review.
+
+## Browser credential autofill
+
+Task: [#56](https://git.sendico.io/tech/sxchnge/issues/56), branch `auth-56`.
+The consumer auth form groups its mounted inputs in one `AutofillGroup` and
+declares their purpose explicitly:
+
+| Input | Flutter hints | Browser autocomplete |
+| --- | --- | --- |
+| Signup name | `name` with the name keyboard | `name` |
+| Account email | `username`, then `email`, with the email keyboard | `username` |
+| Login password | `password` | `current-password` |
+| Signup password and confirmation | `newPassword` on both | `new-password` |
+
+Flutter uses the first hint on web and Apple platforms. Email is the credential
+username; the email keyboard remains configured separately. Visibility toggles
+keep the password role, so autofill does not depend on detecting masked input.
+The confirmation field participates in the same group as the first password,
+allowing the browser to fill both without copying one controller into the other.
+
+Signup acceptance finalizes autofill before clearing password controllers and
+navigating to email verification. Login finalizes on success; when a second
+factor is required, it waits for verification and login completion. The password
+remains only in the existing form controller during that challenge, then clears
+on completed navigation or cancellation. Invalid input, rejected credentials and
+failed verification do not request saving. Switching auth mode, abandoning the
+form or leaving for unverified-account recovery cancels the autofill context.
+Provider/service/model boundaries and existing request/outcome telemetry are
+unchanged; no field events or credential telemetry are added. Browser popup
+display and pre-submit autofill abandonment remain outside current measurement.
+
+### Verification and release check
+
+Focused widget tests send a platform autofill response with all four signup
+values and check EN/RU controller updates, grouped credential metadata, visibility
+changes, mode switching and abandonment. Auth tests cover validation failures,
+service rejection/retry, stale responses, signup/login acceptance, unverified
+recovery, invalid second-factor codes and cancellation without premature saving.
+Existing narrow/desktop layouts and enlarged-text tests cover the unchanged UI.
+
+Native Safari verification remains a release check: computer-control permission
+was unavailable in this session. On the deployed HTTPS origin with Safari
+AutoFill enabled, focus the signup email and password fields, choose a suggested
+strong password, verify that both password fields populate, then confirm that
+login offers the saved credential. Repeat after showing/hiding passwords and
+switching modes. Browser settings, stored credentials and browser heuristics
+determine whether suggestions appear; automated Flutter tests cannot establish
+that the system popup was displayed or that credentials were saved.
+
+References: [Apple Password AutoFill](https://developer.apple.com/documentation/security/enabling-password-autofill-on-an-html-input-element),
+[Flutter autofill hints](https://api.flutter.dev/flutter/material/TextField/autofillHints.html),
+and [AutofillGroup](https://api.flutter.dev/flutter/widgets/AutofillGroup-class.html).
+
+Recorded validation: `dart format --output=none --set-exit-if-changed` passes for
+all five changed Dart files; `flutter analyze` passes in `frontend/app`;
+`make test-frontend` passes all 212 tests across the app and shared packages.
+`flutter build web` passes. The built page's default rendering path was inspected
+in the in-app browser: login exposes `username`/`current-password` in one HTML
+form; signup exposes `username`, `name` and two `new-password` inputs in one form.
+This verifies the browser metadata, not Safari's credential popup. With Flutter
+web accessibility semantics enabled, unfocused semantic inputs initially use
+framework-default autocomplete values until focused; password-manager behavior
+with assistive technology still requires a native browser audit.

frontend/app/lib/auth/form.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 
 import 'package:go_router/go_router.dart';
 
@@ -63,6 +64,8 @@ class _AuthFormState extends State<AuthForm> {
 
   void _switch(bool signUp) {
     if (signUp == _signUp) return;
+    FocusScope.of(context).unfocus();
+    TextInput.finishAutofillContext(shouldSave: false);
     context.read<JourneyRecorder>().abandon(JourneyExit.modeChange);
     context.read<LoginProvider>().reset();
     context.read<SignupProvider>().reset();
@@ -95,6 +98,7 @@ class _AuthFormState extends State<AuthForm> {
         return;
       }
       final email = _email.text.trim();
+      TextInput.finishAutofillContext();
       _password.clear();
       _confirmation.clear();
       context.goNamed(AppRoutes.verificationSent, extra: email);
@@ -107,13 +111,13 @@ class _AuthFormState extends State<AuthForm> {
       );
       if (!mounted || _signUp) return;
       if (login.state.error == AuthError.accountNotVerified) {
+        TextInput.finishAutofillContext(shouldSave: false);
         _password.clear();
         context.goNamed(AppRoutes.verificationSent, extra: _email.text.trim());
         return;
       }
       final challenge = login.state.result?.challenge;
       if (challenge != null) {
-        _password.clear();
         final grant = await verifyFactor(
           context,
           challenge: challenge,
@@ -123,6 +127,8 @@ class _AuthFormState extends State<AuthForm> {
         );
         if (!mounted || _signUp) return;
         if (grant == null) {
+          TextInput.finishAutofillContext(shouldSave: false);
+          _password.clear();
           login.reset();
           context.read<JourneyRecorder>().abandon(JourneyExit.navigation);
           return;
@@ -137,9 +143,13 @@ class _AuthFormState extends State<AuthForm> {
               !_signUp &&
               identical(login.state.result, accepted) &&
               login.state.status == AuthStatus.success) {
+            TextInput.finishAutofillContext();
+            _password.clear();
             context.go(offer ? '/identity?onboarding=1' : '/accounts');
           }
         }
+      } else if (login.state.status == AuthStatus.success) {
+        TextInput.finishAutofillContext();
       }
     }
   }
@@ -195,7 +205,10 @@ class _AuthFormState extends State<AuthForm> {
           expandedInsets: EdgeInsets.zero,
         ),
         const SizedBox(height: 32),
-        Form(
+        AutofillGroup(
+          // Leaving an unfinished form must not offer to save its credentials.
+          onDisposeAction: AutofillContextAction.cancel,
+          child: Form(
             key: _form,
             autovalidateMode: _submitted
                 ? AutovalidateMode.onUserInteraction
@@ -220,6 +233,8 @@ class _AuthFormState extends State<AuthForm> {
                       errorMaxLines: 3,
                     ),
                     textInputAction: TextInputAction.next,
+                    keyboardType: TextInputType.name,
+                    autofillHints: const [AutofillHints.name],
                     textCapitalization: TextCapitalization.words,
                     validator: (value) => AuthValidation.name(value, l),
                   ),
@@ -236,6 +251,10 @@ class _AuthFormState extends State<AuthForm> {
                     errorMaxLines: 3,
                   ),
                   keyboardType: TextInputType.emailAddress,
+                  autofillHints: const [
+                    AutofillHints.username,
+                    AutofillHints.email,
+                  ],
                   textInputAction: TextInputAction.next,
                   autocorrect: false,
                   validator: (value) => AuthValidation.email(value, l),
@@ -246,6 +265,11 @@ class _AuthFormState extends State<AuthForm> {
                   enabled: !state.isLoading,
                   controller: _password,
                   obscureText: !_showPassword,
+                  autofillHints: [
+                    _signUp
+                        ? AutofillHints.newPassword
+                        : AutofillHints.password,
+                  ],
                   autocorrect: false,
                   enableSuggestions: false,
                   textInputAction: _signUp
@@ -281,6 +305,7 @@ class _AuthFormState extends State<AuthForm> {
                     enabled: !state.isLoading,
                     controller: _confirmation,
                     obscureText: !_showConfirmation,
+                    autofillHints: const [AutofillHints.newPassword],
                     autocorrect: false,
                     enableSuggestions: false,
                     textInputAction: TextInputAction.done,
@@ -310,7 +335,8 @@ class _AuthFormState extends State<AuthForm> {
                 const SizedBox(height: 28),
                 FilledButton(
                   key: const ValueKey('submit'),
-                onPressed: state.isLoading || state.status == AuthStatus.success
+                  onPressed:
+                      state.isLoading || state.status == AuthStatus.success
                       ? null
                       : _submit,
                   child: Padding(
@@ -331,7 +357,9 @@ class _AuthFormState extends State<AuthForm> {
                             ? const SizedBox(
                                 width: 20,
                                 height: 20,
-                              child: CircularProgressIndicator(strokeWidth: 2),
+                                child: CircularProgressIndicator(
+                                  strokeWidth: 2,
+                                ),
                               )
                             : const Icon(Icons.arrow_forward, size: 20),
                       ],
@@ -341,6 +369,7 @@ class _AuthFormState extends State<AuthForm> {
               ],
             ),
           ),
+        ),
         if (state.status == AuthStatus.success ||
             state.status == AuthStatus.error) ...[
           const SizedBox(height: 20),

frontend/app/test/auth_services_test.dart

@@ -92,6 +92,14 @@ void main() {
           findsOneWidget,
         );
         expect(find.byKey(const ValueKey('verification-sent')), findsNothing);
+        expect(
+          tester.testTextInput.log,
+          isNot(
+            contains(
+              isMethodCall('TextInput.finishAutofillContext', arguments: true),
+            ),
+          ),
+        );
         expect(
           tester
               .widget<TextFormField>(find.byKey(const ValueKey('email')))
@@ -153,6 +161,14 @@ void main() {
       '/verification-sent',
     );
     expect(backend.sends, 1);
+    expect(
+      tester.testTextInput.log,
+      isNot(
+        contains(
+          isMethodCall('TextInput.finishAutofillContext', arguments: true),
+        ),
+      ),
+    );
     expect(
       find.textContaining('a verification email is on its way'),
       findsOneWidget,
@@ -198,6 +214,14 @@ void main() {
         find.text('Сервис недоступен. Попробуйте ещё раз.'),
         findsOneWidget,
       );
+      expect(
+        tester.testTextInput.log,
+        isNot(
+          contains(
+            isMethodCall('TextInput.finishAutofillContext', arguments: true),
+          ),
+        ),
+      );
       await tester.tap(button);
       await tester.pump();
       expect(service.calls, hasLength(2));
@@ -207,6 +231,12 @@ void main() {
       await tester.pumpAndSettle();
       expect(find.byKey(const ValueKey('preview-result')), findsOneWidget);
       expect(find.byKey(const ValueKey('auth-error')), findsNothing);
+      expect(
+        tester.testTextInput.log,
+        contains(
+          isMethodCall('TextInput.finishAutofillContext', arguments: true),
+        ),
+      );
       expect(tester.takeException(), isNull);
     },
   );
@@ -237,6 +267,14 @@ void main() {
     await tester.pumpAndSettle();
     expect(find.byKey(const ValueKey('confirmation')), findsOneWidget);
     expect(find.byKey(const ValueKey('preview-result')), findsNothing);
+    expect(
+      tester.testTextInput.log,
+      isNot(
+        contains(
+          isMethodCall('TextInput.finishAutofillContext', arguments: true),
+        ),
+      ),
+    );
     expect(tester.takeException(), isNull);
   });
 }

frontend/app/test/auth_test.dart

@@ -55,6 +55,12 @@ void main() {
       await submit(tester);
       expect(find.text('Enter your email address.'), findsOneWidget);
       expect(find.text('Enter your password.'), findsOneWidget);
+      expect(
+        tester.testTextInput.log.where(
+          (call) => call.method == 'TextInput.finishAutofillContext',
+        ),
+        isEmpty,
+      );
       await tester.enterText(
         find.byKey(const ValueKey('email')),
         'test@example.com',
@@ -79,6 +85,12 @@ void main() {
       await tester.testTextInput.receiveAction(TextInputAction.done);
       await tester.pumpAndSettle();
       expect(find.byKey(const ValueKey('preview-result')), findsOneWidget);
+      expect(
+        tester.testTextInput.log,
+        contains(
+          isMethodCall('TextInput.finishAutofillContext', arguments: true),
+        ),
+      );
       expect(tester.takeException(), isNull);
     },
   );
@@ -104,12 +116,26 @@ void main() {
       );
       await submit(tester);
       expect(find.text('Passwords do not match.'), findsOneWidget);
+      expect(
+        tester.testTextInput.log,
+        isNot(
+          contains(
+            isMethodCall('TextInput.finishAutofillContext', arguments: true),
+          ),
+        ),
+      );
       await tester.enterText(
         find.byKey(const ValueKey('confirmation')),
         'example-password',
       );
       await submit(tester);
       expect(find.byKey(const ValueKey('verification-sent')), findsOneWidget);
+      expect(
+        tester.testTextInput.log,
+        contains(
+          isMethodCall('TextInput.finishAutofillContext', arguments: true),
+        ),
+      );
       await tester.ensureVisible(
         find.byKey(const ValueKey('demo-confirmation')),
       );

frontend/app/test/autofill_test.dart

@@ -0,0 +1,149 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:sxchnge_app/main.dart';
+import 'package:sxchnge_app/providers/locale.dart';
+
+Finder field(String key) => find.byKey(ValueKey(key));
+
+EditableTextState editor(WidgetTester tester, String key) =>
+    tester.state<EditableTextState>(
+      find.descendant(of: field(key), matching: find.byType(EditableText)),
+    );
+
+void main() {
+  for (final language in ['en', 'ru']) {
+    testWidgets(
+      'platform autofill fills the signup credential group ($language)',
+      (tester) async {
+        tester.view.physicalSize = const Size(1440, 1200);
+        tester.view.devicePixelRatio = 1;
+        addTearDown(tester.view.resetPhysicalSize);
+        addTearDown(tester.view.resetDevicePixelRatio);
+        await tester.pumpWidget(
+          SxchngeApp(
+            localeProvider: LocaleProvider(initialLocale: Locale(language)),
+          ),
+        );
+        await tester.pumpAndSettle();
+        await tester.tap(
+          find.text(language == 'ru' ? 'Регистрация' : 'Sign up'),
+        );
+        await tester.pumpAndSettle();
+        await tester.showKeyboard(field('email'));
+
+        final configuration = tester.testTextInput.setClientArgs!;
+        expect(
+          configuration['inputType']['name'],
+          'TextInputType.emailAddress',
+        );
+        final fields = (configuration['fields'] as List).cast<Map>();
+        expect(fields, hasLength(4));
+        expect(
+          fields.map((field) => field['autofill']['hints'].first),
+          containsAll(['name', 'username', 'newPassword', 'newPassword']),
+        );
+
+        const values = {
+          'name': 'Alex Example',
+          'email': 'alex@example.com',
+          'password': 'generated-example-password',
+          'confirmation': 'generated-example-password',
+        };
+        await tester.binding.defaultBinaryMessenger.handlePlatformMessage(
+          SystemChannels.textInput.name,
+          SystemChannels.textInput.codec.encodeMethodCall(
+            MethodCall('TextInputClient.updateEditingStateWithTag', [
+              0,
+              {
+                for (final entry in values.entries)
+                  editor(tester, entry.key).autofillId: TextEditingValue(
+                    text: entry.value,
+                  ).toJSON(),
+              },
+            ]),
+          ),
+          (_) {},
+        );
+        await tester.pumpAndSettle();
+        for (final entry in values.entries) {
+          expect(
+            editor(tester, entry.key).currentTextEditingValue.text,
+            entry.value,
+          );
+        }
+
+        // A visibility change must retain both the supplied value and its role.
+        await tester.tap(
+          find.byTooltip(
+            language == 'ru' ? 'Показать пароль' : 'Show password',
+          ),
+        );
+        await tester.pump();
+        expect(editor(tester, 'password').widget.obscureText, isFalse);
+        expect(editor(tester, 'password').widget.autofillHints, [
+          'newPassword',
+        ]);
+        expect(
+          editor(tester, 'password').currentTextEditingValue.text,
+          values['password'],
+        );
+
+        await tester.tap(find.text(language == 'ru' ? 'Войти' : 'Log in'));
+        await tester.pumpAndSettle();
+        await tester.showKeyboard(field('email'));
+        final loginFields =
+            (tester.testTextInput.setClientArgs!['fields'] as List).cast<Map>();
+        expect(loginFields, hasLength(2));
+        expect(loginFields.map((field) => field['autofill']['hints'].first), [
+          'username',
+          'password',
+        ]);
+        expect(
+          editor(tester, 'password').currentTextEditingValue.text,
+          isEmpty,
+        );
+        expect(
+          tester.testTextInput.log,
+          contains(
+            isMethodCall('TextInput.finishAutofillContext', arguments: false),
+          ),
+        );
+        expect(
+          tester.testTextInput.log,
+          isNot(
+            contains(
+              isMethodCall('TextInput.finishAutofillContext', arguments: true),
+            ),
+          ),
+        );
+      },
+    );
+  }
+
+  testWidgets('leaving an unfinished auth form cancels saving', (tester) async {
+    await tester.pumpWidget(const SxchngeApp());
+    await tester.pumpAndSettle();
+    await tester.enterText(field('email'), 'alex@example.com');
+    await tester.enterText(field('password'), 'unfinished-password');
+    tester.testTextInput.log.clear();
+    await tester.pumpWidget(const SizedBox.shrink());
+    await tester.pumpAndSettle();
+    expect(
+      tester.testTextInput.log,
+      contains(
+        isMethodCall('TextInput.finishAutofillContext', arguments: false),
+      ),
+    );
+    expect(
+      tester.testTextInput.log,
+      isNot(
+        contains(
+          isMethodCall('TextInput.finishAutofillContext', arguments: true),
+        ),
+      ),
+    );
+  });
+}

frontend/app/test/two_factor_test.dart

@@ -148,13 +148,38 @@ void main() {
     await signIn(t);
     expect(find.byKey(const ValueKey('two-factor-code')), findsOneWidget);
     expect(find.byKey(const ValueKey('preview-result')), findsNothing);
+    expect(
+      t.testTextInput.log,
+      isNot(
+        contains(
+          isMethodCall('TextInput.finishAutofillContext', arguments: true),
+        ),
+      ),
+    );
     expect(
       analytics.events.where((e) => e.kind == JourneyKind.login && e.terminal),
       isEmpty,
     );
+    await t.enterText(find.byKey(const ValueKey('two-factor-code')), '000000');
+    await tapFactor(t, 'two-factor-confirm');
+    expect(find.byKey(const ValueKey('two-factor-error')), findsOneWidget);
+    expect(
+      t.testTextInput.log,
+      isNot(
+        contains(
+          isMethodCall('TextInput.finishAutofillContext', arguments: true),
+        ),
+      ),
+    );
     await t.enterText(find.byKey(const ValueKey('two-factor-code')), '123456');
     await tapFactor(t, 'two-factor-confirm');
     expect(find.byKey(const ValueKey('account-eur')), findsOneWidget);
+    expect(
+      t.testTextInput.log,
+      contains(
+        isMethodCall('TextInput.finishAutofillContext', arguments: true),
+      ),
+    );
     final login = analytics.events
         .where((e) => e.kind == JourneyKind.login)
         .toList();
@@ -172,6 +197,20 @@ void main() {
     await signIn(t);
     await tapFactor(t, 'two-factor-cancel');
     expect(find.byKey(const ValueKey('email')), findsOneWidget);
+    expect(
+      t.testTextInput.log,
+      contains(
+        isMethodCall('TextInput.finishAutofillContext', arguments: false),
+      ),
+    );
+    expect(
+      t.testTextInput.log,
+      isNot(
+        contains(
+          isMethodCall('TextInput.finishAutofillContext', arguments: true),
+        ),
+      ),
+    );
     expect(find.byKey(const ValueKey('preview-result')), findsNothing);
     expect(
       t