Connect sign-up to Sendico Facts intake (#46)

frontend/app/test/auth_services_test.dart

@@ -6,6 +6,8 @@ import 'package:flutter_test/flutter_test.dart';
 
 import 'package:go_router/go_router.dart';
 
+import 'package:sxchnge_analytics/sxchnge_analytics.dart';
+
 import 'package:sxchnge_auth/sxchnge_auth.dart';
 
 import 'package:sxchnge_app/main.dart';
@@ -41,6 +43,84 @@ class UnverifiedBackend extends BackendAuthServices {
 }
 
 void main() {
+  for (final language in ['en', 'ru']) {
+    testWidgets(
+      'signup requiring assistance preserves input and records failure ($language)',
+      (tester) async {
+        tester.view.physicalSize = const Size(390, 844);
+        tester.view.devicePixelRatio = 1;
+        tester.platformDispatcher.textScaleFactorTestValue = 1.5;
+        addTearDown(tester.view.resetPhysicalSize);
+        addTearDown(tester.view.resetDevicePixelRatio);
+        addTearDown(tester.platformDispatcher.clearTextScaleFactorTestValue);
+        final analytics = DummyAnalyticsService();
+        final locale = LocaleProvider(initialLocale: Locale(language));
+        await tester.pumpWidget(
+          SxchngeApp(
+            localeProvider: locale,
+            analyticsService: analytics,
+            signupService: const DummySignupService(
+              delay: Duration.zero,
+              failure: AuthError.signupNeedsAssistance,
+            ),
+          ),
+        );
+        await tester.pumpAndSettle();
+        final signupLabel = language == 'ru' ? 'Регистрация' : 'Sign up';
+        await tester.ensureVisible(find.text(signupLabel));
+        await tester.tap(find.text(signupLabel));
+        await tester.pumpAndSettle();
+        for (final entry in {
+          'name': 'Ada Lovelace',
+          'email': 'ada@example.com',
+          'password': 'password preserved',
+          'confirmation': 'password preserved',
+        }.entries) {
+          await tester.enterText(find.byKey(ValueKey(entry.key)), entry.value);
+        }
+        await tester.ensureVisible(find.byKey(const ValueKey('submit')));
+        await tester.tap(find.byKey(const ValueKey('submit')));
+        await tester.pumpAndSettle();
+        final feedback = find.byKey(const ValueKey('auth-error'));
+        await tester.ensureVisible(feedback);
+        expect(
+          find.text(
+            language == 'ru'
+                ? 'Не удалось завершить создание аккаунта. Обратитесь в службу поддержки.'
+                : 'We could not finish setting up your account. Please contact support.',
+          ),
+          findsOneWidget,
+        );
+        expect(find.byKey(const ValueKey('verification-sent')), findsNothing);
+        expect(
+          tester
+              .widget<TextFormField>(find.byKey(const ValueKey('email')))
+              .controller!
+              .text,
+          'ada@example.com',
+        );
+        expect(
+          tester
+              .widget<TextFormField>(find.byKey(const ValueKey('password')))
+              .controller!
+              .text,
+          'password preserved',
+        );
+        expect(
+          analytics.events.where((event) => event.name == 'auth_signup_failed'),
+          hasLength(1),
+        );
+        expect(
+          analytics.events.where(
+            (event) => event.name == 'auth_signup_succeeded',
+          ),
+          isEmpty,
+        );
+        expect(tester.takeException(), isNull);
+      },
+    );
+  }
+
   testWidgets('backend mode gates workspace and recovers unverified login', (
     tester,
   ) async {