merge: 合并登录异常居中吐司

docs/plans/2026-10-22-login-error-center-toast.md

@@ -0,0 +1,29 @@
+# 登录异常居中吐司
+
+## 目标
+
+- 将上一版认证异常 AlertDialog 替换为无交互的屏幕居中吐司。
+- 吐司淡入展示约 2 秒后自动淡出，不遮罩、不拦截手势。
+- 同一时刻只存在一个吐司，新消息替换旧消息。
+
+## 实施步骤
+
+1. 删除 `centered_error_dialog.dart`，新增 `centered_toast.dart`。
+2. 认证页和手机号弹窗异常路径改用 `showCenteredToast`，保留 busy 复位和成功 SnackBar。
+3. 清理不再使用的认证错误标题与确认按钮 l10n 键，重新生成 AppLocalizations。
+4. 更新认证测试为吐司断言，并补单例替换、自动消失测试。
+5. 执行 `dart analyze lib test` 与 `flutter test --no-pub`，回填 PROGRESS 后提交合并。
+
+## 风险 / 待确认
+
+- 吐司使用 root Overlay，认证路由退出时仍会按自身计时器自动清理。
+- 测试必须 pump 超过展示和淡出时长，确保不遗留 Timer 或 OverlayEntry。
+
+## 执行结果
+
+- 已删除 AlertDialog 组件，新增 OverlayEntry 居中吐司。
+- 邮箱和手机号异常改用吐司；busy 复位、成功 SnackBar 和本地内联校验保持不变。
+- 已清理三个不再使用的 l10n 键并重新生成 AppLocalizations。
+- 覆盖单例替换、点击穿透、自动消失、接口异常和本地校验不弹吐司。
+- `dart analyze lib test` 零告警，`flutter test --no-pub` 573 项全过。
+- 未启停服务，未操作真机。

docs/plans/PROGRESS.md

@@ -233,3 +233,36 @@ $ flutter test --no-pub
 解读：登录异常、注册标题、未知异常回退、本地校验不弹窗、遮罩/按钮关闭和手机号两条
 异常路径均通过；全量静态分析零告警，570 项测试全过。`pubspec.lock` 已还原，
 未启停服务，未操作真机。
+
+## 2026-10-22 登录异常调整为中心吐司
+
+- 已从 `develop`（`11e37a9`）创建 `feature/login-error-center-toast`。
+- 删除 AlertDialog 组件，新增 OverlayEntry 居中吐司：淡入淡出、约 2 秒消失、不拦截手势。
+- 吐司保持全局单例，新消息替换旧消息；邮箱与手机号异常路径均已切换。
+- 本地表单校验继续内联，手机号验证码发送成功 SnackBar 保持不变。
+- 清理 `authLoginFailed` / `authRegisterFailed` / `authErrorConfirm` 并重新生成 l10n。
+
+执行命令与原始输出：
+
+```text
+$ flutter gen-l10n
+Because l10n.yaml exists, the options defined there will be used instead.
+To use the command line arguments, delete the l10n.yaml file in the Flutter project.
+
+$ flutter test --no-pub test/core/centered_toast_test.dart
+00:00 +3: All tests passed!
+
+$ flutter test --no-pub test/auth/auth_page_test.dart test/auth/phone_auth_sheet_test.dart
+00:02 +20: All tests passed!
+
+$ dart analyze lib test
+Analyzing lib, test...
+No issues found!
+
+$ flutter test --no-pub
+01:00 +573: All tests passed!
+```
+
+解读：吐司单例替换、点击穿透和自动消失通过；认证异常与本地校验路径通过；
+全量静态分析零告警，573 项测试全过。`pubspec.lock` 已还原，未启停服务，
+未操作真机。

lib/core/widgets/centered_error_dialog.dart

@@ -1,67 +0,0 @@
-// Author: fruit.com.cn
-
-import 'package:flutter/material.dart';
-
-import '../../l10n/app_localizations.dart';
-import '../theme/app_colors.dart';
-
-const Key _dialogKey = Key('centered-error-dialog');
-const Key _confirmKey = Key('centered-error-confirm');
-const double _dialogRadius = 16;
-const double _titleHorizontalInset = 24;
-const double _titleTopInset = 24;
-const double _contentHorizontalInset = 24;
-const double _contentTopInset = 12;
-const double _contentBottomInset = 8;
-const double _actionsHorizontalInset = 16;
-const double _actionsBottomInset = 12;
-const EdgeInsets _titlePadding = EdgeInsets.fromLTRB(
-  _titleHorizontalInset,
-  _titleTopInset,
-  _titleHorizontalInset,
-  0,
-);
-const EdgeInsets _contentPadding = EdgeInsets.fromLTRB(
-  _contentHorizontalInset,
-  _contentTopInset,
-  _contentHorizontalInset,
-  _contentBottomInset,
-);
-const EdgeInsets _actionsPadding = EdgeInsets.fromLTRB(
-  _actionsHorizontalInset,
-  0,
-  _actionsHorizontalInset,
-  _actionsBottomInset,
-);
-
-/// Shows a reusable error dialog centered on the screen.
-Future<void> showCenteredErrorDialog(
-  BuildContext context, {
-  required String title,
-  required String message,
-}) async {
-  final l10n = AppLocalizations.of(context)!;
-  await showDialog<void>(
-    context: context,
-    barrierDismissible: true,
-    builder: (dialogContext) => AlertDialog(
-      key: _dialogKey,
-      backgroundColor: AppColors.card,
-      shape: RoundedRectangleBorder(
-        borderRadius: BorderRadius.circular(_dialogRadius),
-      ),
-      titlePadding: _titlePadding,
-      contentPadding: _contentPadding,
-      title: Text(title),
-      content: Text(message),
-      actionsPadding: _actionsPadding,
-      actions: [
-        TextButton(
-          key: _confirmKey,
-          onPressed: () => Navigator.of(dialogContext).pop(),
-          child: Text(l10n.authErrorConfirm),
-        ),
-      ],
-    ),
-  );
-}

lib/core/widgets/centered_toast.dart

@@ -0,0 +1,128 @@
+// Author: fruit.com.cn
+
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+
+const Key _toastKey = Key('centered-toast');
+const Duration _fadeDuration = Duration(milliseconds: 200);
+const Duration _visibleDuration = Duration(seconds: 2);
+const double _toastRadius = 12;
+const double _toastMaxWidth = 320;
+const double _toastHorizontalInset = 20;
+const double _toastVerticalInset = 12;
+const double _toastBackgroundOpacity = 0.78;
+const TextStyle _toastTextStyle = TextStyle(
+  color: Colors.white,
+  fontSize: 14,
+  height: 1.4,
+  fontWeight: FontWeight.w500,
+);
+const EdgeInsets _toastPadding = EdgeInsets.symmetric(
+  horizontal: _toastHorizontalInset,
+  vertical: _toastVerticalInset,
+);
+
+OverlayEntry? _activeToast;
+
+/// Shows a lightweight centered message and replaces any active toast.
+void showCenteredToast(BuildContext context, String message) {
+  _removeActiveToast();
+  final overlay = Overlay.of(context, rootOverlay: true);
+  late final OverlayEntry entry;
+  entry = OverlayEntry(
+    builder: (_) => _CenteredToast(
+      message: message,
+      onDismissed: () {
+        if (!identical(_activeToast, entry)) return;
+        _activeToast = null;
+        if (entry.mounted) entry.remove();
+      },
+    ),
+  );
+  _activeToast = entry;
+  overlay.insert(entry);
+}
+
+void _removeActiveToast() {
+  final entry = _activeToast;
+  _activeToast = null;
+  if (entry != null && entry.mounted) entry.remove();
+}
+
+class _CenteredToast extends StatefulWidget {
+  const _CenteredToast({required this.message, required this.onDismissed});
+
+  final String message;
+  final VoidCallback onDismissed;
+
+  @override
+  State<_CenteredToast> createState() => _CenteredToastState();
+}
+
+class _CenteredToastState extends State<_CenteredToast>
+    with SingleTickerProviderStateMixin {
+  late final AnimationController _opacity = AnimationController(
+    vsync: this,
+    duration: _fadeDuration,
+  );
+  Timer? _dismissTimer;
+
+  @override
+  void initState() {
+    super.initState();
+    _opacity.forward();
+    _dismissTimer = Timer(_visibleDuration, _dismiss);
+  }
+
+  Future<void> _dismiss() async {
+    try {
+      await _opacity.reverse();
+    } on TickerCanceled {
+      return;
+    }
+    if (mounted) widget.onDismissed();
+  }
+
+  @override
+  void dispose() {
+    _dismissTimer?.cancel();
+    _opacity.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Positioned.fill(
+      child: IgnorePointer(
+        child: Center(
+          child: FadeTransition(
+            opacity: CurvedAnimation(
+              parent: _opacity,
+              curve: Curves.easeOutCubic,
+            ),
+            child: Material(
+              type: MaterialType.transparency,
+              child: Container(
+                key: _toastKey,
+                constraints: const BoxConstraints(maxWidth: _toastMaxWidth),
+                padding: _toastPadding,
+                decoration: BoxDecoration(
+                  color: Colors.black.withValues(
+                    alpha: _toastBackgroundOpacity,
+                  ),
+                  borderRadius: BorderRadius.circular(_toastRadius),
+                ),
+                child: Text(
+                  widget.message,
+                  textAlign: TextAlign.center,
+                  style: _toastTextStyle,
+                ),
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/l10n/app_en.arb

@@ -435,9 +435,6 @@
   "authPasswordLength": "Password must be 8-64 characters",
   "authPasswordWeak": "Password needs both letters and numbers",
   "authNetworkError": "Network error, please try again",
-  "authLoginFailed": "Login failed",
-  "authRegisterFailed": "Registration failed",
-  "authErrorConfirm": "OK",
   "authSwitchToSignUp": "New here? Create an account",
   "authSwitchToSignIn": "Already have an account? Sign in",
   "authGateTitle": "Sign in to continue",

lib/l10n/app_id.arb

@@ -409,9 +409,6 @@
   "authPasswordLength": "Kata sandi harus 8-64 karakter",
   "authPasswordWeak": "Kata sandi perlu huruf dan angka",
   "authNetworkError": "Jaringan bermasalah, coba lagi",
-  "authLoginFailed": "Gagal masuk",
-  "authRegisterFailed": "Pendaftaran gagal",
-  "authErrorConfirm": "Mengerti",
   "authSwitchToSignUp": "Baru di sini? Buat akun",
   "authSwitchToSignIn": "Sudah punya akun? Masuk",
   "authGateTitle": "Masuk untuk melanjutkan",

lib/l10n/app_localizations.dart

@@ -1888,24 +1888,6 @@ abstract class AppLocalizations {
   /// **'Network error, please try again'**
   String get authNetworkError;
 
-  /// No description provided for @authLoginFailed.
-  ///
-  /// In en, this message translates to:
-  /// **'Login failed'**
-  String get authLoginFailed;
-
-  /// No description provided for @authRegisterFailed.
-  ///
-  /// In en, this message translates to:
-  /// **'Registration failed'**
-  String get authRegisterFailed;
-
-  /// No description provided for @authErrorConfirm.
-  ///
-  /// In en, this message translates to:
-  /// **'OK'**
-  String get authErrorConfirm;
-
   /// No description provided for @authSwitchToSignUp.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_en.dart

@@ -958,15 +958,6 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get authNetworkError => 'Network error, please try again';
 
-  @override
-  String get authLoginFailed => 'Login failed';
-
-  @override
-  String get authRegisterFailed => 'Registration failed';
-
-  @override
-  String get authErrorConfirm => 'OK';
-
   @override
   String get authSwitchToSignUp => 'New here? Create an account';
 

lib/l10n/app_localizations_id.dart

@@ -962,15 +962,6 @@ class AppLocalizationsId extends AppLocalizations {
   @override
   String get authNetworkError => 'Jaringan bermasalah, coba lagi';
 
-  @override
-  String get authLoginFailed => 'Gagal masuk';
-
-  @override
-  String get authRegisterFailed => 'Pendaftaran gagal';
-
-  @override
-  String get authErrorConfirm => 'Mengerti';
-
   @override
   String get authSwitchToSignUp => 'Baru di sini? Buat akun';
 

lib/l10n/app_localizations_zh.dart

@@ -946,15 +946,6 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get authNetworkError => '网络异常，请稍后重试';
 
-  @override
-  String get authLoginFailed => '登录失败';
-
-  @override
-  String get authRegisterFailed => '注册失败';
-
-  @override
-  String get authErrorConfirm => '知道了';
-
   @override
   String get authSwitchToSignUp => '还没有账号？去注册';
 

lib/l10n/app_zh.arb

@@ -371,9 +371,6 @@
   "authPasswordLength": "密码长度需在 8-64 位之间",
   "authPasswordWeak": "密码需同时包含字母和数字",
   "authNetworkError": "网络异常，请稍后重试",
-  "authLoginFailed": "登录失败",
-  "authRegisterFailed": "注册失败",
-  "authErrorConfirm": "知道了",
   "authSwitchToSignUp": "还没有账号？去注册",
   "authSwitchToSignIn": "已有账号？去登录",
   "authGateTitle": "登录后可继续",

lib/pages/auth/auth_view.dart

@@ -12,7 +12,7 @@ import '../../core/platform/keyboard_inset.dart';
 import '../../core/theme/app_colors.dart';
 import '../../core/theme/app_dimens.dart';
 import '../../core/theme/app_theme.dart';
-import '../../core/widgets/centered_error_dialog.dart';
+import '../../core/widgets/centered_toast.dart';
 import '../../core/widgets/subpage_header.dart';
 import '../../l10n/app_localizations.dart';
 import 'auth_logic.dart';
@@ -251,11 +251,7 @@ class _AuthPageState extends State<AuthPage> {
       if (mounted) setState(() => _logic.busy = false);
     }
     if (!mounted || failureMessage == null) return;
-    await showCenteredErrorDialog(
-      context,
-      title: _logic.signUpMode ? l10n.authRegisterFailed : l10n.authLoginFailed,
-      message: failureMessage,
-    );
+    showCenteredToast(context, failureMessage);
   }
 
   @override

lib/pages/auth/phone_auth_sheet.dart

@@ -11,7 +11,7 @@ import '../../core/data/services/auth_controller.dart';
 import '../../core/platform/haptics.dart';
 import '../../core/platform/keyboard_inset.dart';
 import '../../core/theme/app_colors.dart';
-import '../../core/widgets/centered_error_dialog.dart';
+import '../../core/widgets/centered_toast.dart';
 import '../../l10n/app_localizations.dart';
 
 const double _fieldHeight = 52;
@@ -187,7 +187,7 @@ class _PhoneAuthSheetState extends State<PhoneAuthSheet> {
       if (mounted) setState(() => _sending = false);
     }
     if (mounted && failureMessage != null) {
-      await _showFailure(failureMessage);
+      showCenteredToast(context, failureMessage);
     }
   }
 
@@ -235,19 +235,10 @@ class _PhoneAuthSheetState extends State<PhoneAuthSheet> {
       if (mounted) setState(() => _submitting = false);
     }
     if (mounted && failureMessage != null) {
-      await _showFailure(failureMessage);
+      showCenteredToast(context, failureMessage);
     }
   }
 
-  Future<void> _showFailure(String message) {
-    final l10n = AppLocalizations.of(context)!;
-    return showCenteredErrorDialog(
-      context,
-      title: _signUp ? l10n.authRegisterFailed : l10n.authLoginFailed,
-      message: message,
-    );
-  }
-
   void _switchMode() {
     setState(() {
       _signUp = !_signUp;

test/auth/auth_page_test.dart

@@ -78,7 +78,7 @@ void main() {
 
     expect(find.text('Enter your email'), findsOneWidget);
     expect(find.text('Welcome back'), findsOneWidget);
-    expect(find.byKey(const Key('centered-error-dialog')), findsNothing);
+    expect(find.byKey(const Key('centered-toast')), findsNothing);
   });
 
   testWidgets(
@@ -95,11 +95,11 @@ void main() {
         find.text('Password needs both letters and numbers'),
         findsOneWidget,
       );
-      expect(find.byKey(const Key('centered-error-dialog')), findsNothing);
+      expect(find.byKey(const Key('centered-toast')), findsNothing);
     },
   );
 
-  testWidgets('should_show_centered_dialog_when_login_api_returns_an_error', (
+  testWidgets('should_show_centered_toast_when_login_api_returns_an_error', (
     tester,
   ) async {
     final api = _FailingAuthApi(loginMessage: 'Invalid email or password');
@@ -110,13 +110,13 @@ void main() {
     await tester.tap(find.byKey(const Key('auth-submit')));
     await tester.pumpAndSettle();
 
-    final dialog = find.byKey(const Key('centered-error-dialog'));
-    expect(dialog, findsOneWidget);
-    expect(find.text('Login failed'), findsOneWidget);
+    final toast = find.byKey(const Key('centered-toast'));
+    expect(toast, findsOneWidget);
     expect(find.text('Invalid email or password'), findsOneWidget);
+    expect(find.byType(AlertDialog), findsNothing);
     expect(api.loginCalls, 1);
     expect(
-      tester.getCenter(dialog),
+      tester.getCenter(toast),
       offsetMoreOrLessEquals(
         tester.getCenter(find.byType(Scaffold)),
         epsilon: 1,
@@ -129,32 +129,29 @@ void main() {
       isNotNull,
     );
 
-    await tester.tap(find.byKey(const Key('centered-error-confirm')));
-    await tester.pumpAndSettle();
-    expect(dialog, findsNothing);
+    await _pumpToastAway(tester);
+    expect(toast, findsNothing);
   });
 
-  testWidgets(
-    'should_show_registration_failed_title_when_register_api_returns_an_error',
-    (tester) async {
-      final api = _FailingAuthApi(registerMessage: 'Email already exists');
-      await pumpAuthPage(tester, signUp: true, api: api);
-      await _enterValidCredentials(tester);
+  testWidgets('should_show_centered_toast_when_register_api_returns_an_error', (
+    tester,
+  ) async {
+    final api = _FailingAuthApi(registerMessage: 'Email already exists');
+    await pumpAuthPage(tester, signUp: true, api: api);
+    await _enterValidCredentials(tester);
 
-      await tester.ensureVisible(find.byKey(const Key('auth-submit')));
-      await tester.tap(find.byKey(const Key('auth-submit')));
-      await tester.pumpAndSettle();
+    await tester.ensureVisible(find.byKey(const Key('auth-submit')));
+    await tester.tap(find.byKey(const Key('auth-submit')));
+    await tester.pumpAndSettle();
 
-      expect(find.byKey(const Key('centered-error-dialog')), findsOneWidget);
-      expect(find.text('Registration failed'), findsOneWidget);
-      expect(find.text('Email already exists'), findsOneWidget);
-      expect(api.registerCalls, 1);
+    expect(find.byKey(const Key('centered-toast')), findsOneWidget);
+    expect(find.text('Email already exists'), findsOneWidget);
+    expect(find.byType(AlertDialog), findsNothing);
+    expect(api.registerCalls, 1);
 
-      await tester.tapAt(const Offset(8, 8));
-      await tester.pumpAndSettle();
-      expect(find.byKey(const Key('centered-error-dialog')), findsNothing);
-    },
-  );
+    await _pumpToastAway(tester);
+    expect(find.byKey(const Key('centered-toast')), findsNothing);
+  });
 
   testWidgets(
     'should_show_network_error_when_login_throws_an_unknown_exception',
@@ -167,8 +164,12 @@ void main() {
       await tester.tap(find.byKey(const Key('auth-submit')));
       await tester.pumpAndSettle();
 
-      expect(find.byKey(const Key('centered-error-dialog')), findsOneWidget);
+      expect(find.byKey(const Key('centered-toast')), findsOneWidget);
       expect(find.text('Network error, please try again'), findsOneWidget);
+      expect(find.byType(AlertDialog), findsNothing);
+
+      await _pumpToastAway(tester);
+      expect(find.byKey(const Key('centered-toast')), findsNothing);
     },
   );
 
@@ -422,6 +423,11 @@ Future<void> _enterValidCredentials(WidgetTester tester) async {
   await tester.enterText(find.byKey(const Key('auth-password')), 'abcd1234');
 }
 
+Future<void> _pumpToastAway(WidgetTester tester) async {
+  await tester.pump(const Duration(seconds: 3));
+  await tester.pumpAndSettle();
+}
+
 void _expectAboveKeyboard(WidgetTester tester, Key fieldKey, double inset) {
   final screenHeight =
       tester.view.physicalSize.height / tester.view.devicePixelRatio;

test/auth/phone_auth_sheet_test.dart

@@ -98,10 +98,10 @@ void main() {
 
     expect(find.text('Enter a valid phone number'), findsOneWidget);
     expect(adapter.requests, isEmpty);
-    expect(find.byKey(const Key('centered-error-dialog')), findsNothing);
+    expect(find.byKey(const Key('centered-toast')), findsNothing);
   });
 
-  testWidgets('should_show_centered_dialog_when_otp_request_fails', (
+  testWidgets('should_show_centered_toast_when_otp_request_fails', (
     tester,
   ) async {
     final api = _FailingPhoneAuthApi(sendOtpMessage: 'Too many OTP requests');
@@ -117,9 +117,9 @@ void main() {
     await tester.tap(find.byKey(const Key('auth-send-code')));
     await tester.pumpAndSettle();
 
-    expect(find.byKey(const Key('centered-error-dialog')), findsOneWidget);
-    expect(find.text('Login failed'), findsOneWidget);
+    expect(find.byKey(const Key('centered-toast')), findsOneWidget);
     expect(find.text('Too many OTP requests'), findsOneWidget);
+    expect(find.byType(AlertDialog), findsNothing);
     expect(api.sendOtpCalls, 1);
     expect(
       tester
@@ -127,9 +127,12 @@ void main() {
           .onPressed,
       isNotNull,
     );
+
+    await _pumpToastAway(tester);
+    expect(find.byKey(const Key('centered-toast')), findsNothing);
   });
 
-  testWidgets('should_show_centered_dialog_when_phone_login_fails', (
+  testWidgets('should_show_centered_toast_when_phone_login_fails', (
     tester,
   ) async {
     final api = _FailingPhoneAuthApi(loginMessage: 'Invalid verification code');
@@ -146,9 +149,9 @@ void main() {
     await tester.tap(find.byKey(const Key('auth-phone-submit')));
     await tester.pumpAndSettle();
 
-    expect(find.byKey(const Key('centered-error-dialog')), findsOneWidget);
-    expect(find.text('Login failed'), findsOneWidget);
+    expect(find.byKey(const Key('centered-toast')), findsOneWidget);
     expect(find.text('Invalid verification code'), findsOneWidget);
+    expect(find.byType(AlertDialog), findsNothing);
     expect(api.loginWithPhoneCalls, 1);
     expect(
       tester
@@ -156,6 +159,9 @@ void main() {
           .onPressed,
       isNotNull,
     );
+
+    await _pumpToastAway(tester);
+    expect(find.byKey(const Key('centered-toast')), findsNothing);
   });
 
   testWidgets('should_keep_code_above_ios_keyboard', (tester) async {
@@ -191,6 +197,11 @@ void main() {
   });
 }
 
+Future<void> _pumpToastAway(WidgetTester tester) async {
+  await tester.pump(const Duration(seconds: 3));
+  await tester.pumpAndSettle();
+}
+
 class _FailingPhoneAuthApi extends AuthApi {
   _FailingPhoneAuthApi({
     this.sendOtpMessage = 'otp failed',

test/core/centered_toast_test.dart

@@ -0,0 +1,93 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:fruitshorts/core/widgets/centered_toast.dart';
+
+void main() {
+  testWidgets('should_replace_previous_toast_when_shown_again', (tester) async {
+    late BuildContext hostContext;
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Builder(
+          builder: (context) {
+            hostContext = context;
+            return const Scaffold(body: SizedBox.expand());
+          },
+        ),
+      ),
+    );
+
+    showCenteredToast(hostContext, 'first message');
+    await tester.pump();
+    showCenteredToast(hostContext, 'second message');
+    await tester.pump();
+
+    expect(find.byKey(const Key('centered-toast')), findsOneWidget);
+    expect(find.text('second message'), findsOneWidget);
+    expect(find.text('first message'), findsNothing);
+
+    await tester.pump(const Duration(seconds: 2));
+    await tester.pump(const Duration(milliseconds: 200));
+    expect(find.byKey(const Key('centered-toast')), findsNothing);
+  });
+
+  testWidgets('should_allow_underlying_gesture_when_toast_is_visible', (
+    tester,
+  ) async {
+    late BuildContext hostContext;
+    var taps = 0;
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Builder(
+          builder: (context) {
+            hostContext = context;
+            return Scaffold(
+              body: GestureDetector(
+                key: const Key('toast-host'),
+                behavior: HitTestBehavior.opaque,
+                onTap: () => taps++,
+                child: const SizedBox.expand(),
+              ),
+            );
+          },
+        ),
+      ),
+    );
+    showCenteredToast(hostContext, 'tap-through');
+    await tester.pump();
+
+    await tester.tapAt(
+      tester.getCenter(find.byKey(const Key('centered-toast'))),
+    );
+
+    expect(taps, 1);
+    await tester.pump(const Duration(seconds: 2));
+    await tester.pump(const Duration(milliseconds: 200));
+  });
+
+  testWidgets('should_replace_toast_when_previous_toast_is_fading_out', (
+    tester,
+  ) async {
+    late BuildContext hostContext;
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Builder(
+          builder: (context) {
+            hostContext = context;
+            return const Scaffold(body: SizedBox.expand());
+          },
+        ),
+      ),
+    );
+
+    showCenteredToast(hostContext, 'first message');
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 2));
+    showCenteredToast(hostContext, 'replacement message');
+    await tester.pump();
+
+    expect(tester.takeException(), isNull);
+    expect(find.text('replacement message'), findsOneWidget);
+    await tester.pump(const Duration(seconds: 3));
+    await tester.pumpAndSettle();
+  });
+}