fix(firebase_ui_auth): clear the error on ForgotPasswordScreen after submitting a valid email (#9992)

Author: lesnitsky

packages/firebase_ui_auth/lib/src/views/forgot_password_view.dart

@@ -53,7 +53,11 @@ class _ForgotPasswordViewState extends State<ForgotPasswordView> {
   FirebaseAuthException? exception;
 
   Future<void> _submit(String email) async {
-    setState(() => isLoading = true);
+    setState(() {
+      exception = null;
+      isLoading = true;
+    });
+
     try {
       await auth.sendPasswordResetEmail(
         email: email,

packages/firebase_ui_auth/test/firebase_ui_test.dart

@@ -4,11 +4,13 @@ import 'flows/universal_email_sign_in_flow_test.dart'
     as universal_email_sign_in_flow;
 import 'flows/phone_auth_flow_test.dart' as phone_auth_flow;
 import 'widgets/email_form_test.dart' as email_form;
+import 'views/forgot_password_view_test.dart' as forgot_password_view;
 
 void main() {
   email_auth_flow.main();
   email_link_flow.main();
   universal_email_sign_in_flow.main();
   phone_auth_flow.main();
   email_form.main();
+  forgot_password_view.main();
 }

packages/firebase_ui_auth/test/views/forgot_password_view_test.dart

@@ -0,0 +1,81 @@
+import 'package:firebase_auth/firebase_auth.dart';
+import 'package:firebase_ui_auth/firebase_ui_auth.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mockito/mockito.dart';
+
+import '../test_utils.dart';
+
+class MockFirebaseAuth extends Mock implements FirebaseAuth {
+  @override
+  Future<void> sendPasswordResetEmail({
+    String? email,
+    ActionCodeSettings? actionCodeSettings,
+  }) {
+    return super.noSuchMethod(
+      Invocation.method(
+        #sendPasswordResetEmail,
+        [],
+        {
+          #email: email,
+          #actionCodeSettings: actionCodeSettings,
+        },
+      ),
+      returnValue: Future.value(),
+      returnValueForMissingStub: Future.value(),
+    );
+  }
+}
+
+void main() {
+  group('Forgot password view', () {
+    late Widget widget;
+    late MockFirebaseAuth auth;
+
+    setUpAll(() {
+      auth = MockFirebaseAuth();
+
+      widget = TestMaterialApp(
+        child: ForgotPasswordView(auth: auth),
+      );
+
+      when(auth.sendPasswordResetEmail(email: 'invalid@email')).thenThrow(
+        FirebaseAuthException(
+          message: 'invalid-email',
+          code: 'invalid-email',
+        ),
+      );
+
+      when(auth.sendPasswordResetEmail(email: '[email protected]')).thenAnswer(
+        (_) => Future.value(),
+      );
+    });
+
+    testWidgets('shows error if sendPasswordResetEmail failed', (tester) async {
+      await tester.pumpWidget(widget);
+
+      final input = find.byType(TextField);
+      await tester.enterText(input, 'invalid@email');
+
+      await tester.testTextInput.receiveAction(TextInputAction.done);
+      await tester.pumpAndSettle();
+
+      expect(find.text('invalid-email'), findsOneWidget);
+    });
+
+    testWidgets(
+      "doesn't show ana error on next successful attempt after error",
+      (tester) async {
+        await tester.pumpWidget(widget);
+
+        final input = find.byType(TextField);
+        await tester.enterText(input, '[email protected]');
+
+        await tester.testTextInput.receiveAction(TextInputAction.done);
+        await tester.pumpAndSettle();
+
+        expect(find.byType(ErrorText), findsNothing);
+      },
+    );
+  });
+}