feat: add school authentication entry with guarded import

mobile/lib/app/hepan_app.dart

@@ -5,24 +5,36 @@ import 'app_theme.dart';
 import '../widgets/glass_dock.dart';
 import '../features/timetable/timetable_page.dart';
 import '../features/profile/profile_page.dart';
+import '../features/school/school_session.dart';
 
 class HepanApp extends StatelessWidget {
-  const HepanApp({super.key, required this.controller, this.schoolBuilder});
+  const HepanApp({
+    super.key,
+    required this.controller,
+    this.schoolBuilder,
+    this.school,
+  });
   final AppController controller;
   final Widget Function()? schoolBuilder;
+  final SchoolSession? school;
   @override
   Widget build(BuildContext context) => MaterialApp(
     debugShowCheckedModeBanner: false,
     title: '河畔Everyday',
     theme: hepanTheme(),
-    home: _Shell(controller: controller, schoolBuilder: schoolBuilder),
+    home: _Shell(
+      controller: controller,
+      schoolBuilder: schoolBuilder,
+      school: school,
+    ),
   );
 }
 
 class _Shell extends StatefulWidget {
-  const _Shell({required this.controller, this.schoolBuilder});
+  const _Shell({required this.controller, this.schoolBuilder, this.school});
   final AppController controller;
   final Widget Function()? schoolBuilder;
+  final SchoolSession? school;
   @override
   State<_Shell> createState() => _ShellState();
 }
@@ -71,9 +83,41 @@ class _ShellState extends State<_Shell> with WidgetsBindingObserver {
     }
   }
 
+  Future<void> _logout() async {
+    final choice = await showDialog<int>(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('退出学校登录'),
+        content: const Text('已导入的课表是否保留在手机中？'),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(context, 0),
+            child: const Text('取消'),
+          ),
+          TextButton(
+            onPressed: () => Navigator.pop(context, 1),
+            child: const Text('保留课表'),
+          ),
+          TextButton(
+            onPressed: () => Navigator.pop(context, 2),
+            child: const Text('清除课表'),
+          ),
+        ],
+      ),
+    );
+    if (choice == null || choice == 0) return;
+    await widget.school?.logout();
+    if (choice == 2) {
+      await widget.controller.clearCourses();
+    }
+  }
+
   @override
   Widget build(BuildContext context) => AnimatedBuilder(
-    animation: widget.controller,
+    animation: Listenable.merge([
+      widget.controller,
+      if (widget.school != null) widget.school!,
+    ]),
     builder: (context, _) => Scaffold(
       body: Container(
         decoration: const BoxDecoration(
@@ -118,6 +162,10 @@ class _ShellState extends State<_Shell> with WidgetsBindingObserver {
                           ProfilePage(
                             controller: widget.controller,
                             onLogin: _school,
+                            authStatus: widget.school?.statusLabel ?? '未登录',
+                            onLogout: widget.school?.hasOpened == true
+                                ? _logout
+                                : null,
                           ),
                         ],
                       ),

mobile/lib/features/school/school_auth_page.dart

@@ -0,0 +1,223 @@
+import 'package:flutter/material.dart';
+import 'package:webview_flutter/webview_flutter.dart';
+
+import '../../app/app_controller.dart';
+import '../../app/app_theme.dart';
+import '../profile/import_preview.dart';
+import 'school_session.dart';
+
+class SchoolAuthPage extends StatefulWidget {
+  const SchoolAuthPage({
+    super.key,
+    required this.session,
+    required this.controller,
+  });
+  final SchoolSession session;
+  final AppController controller;
+  @override
+  State<SchoolAuthPage> createState() => _SchoolAuthPageState();
+}
+
+class _SchoolAuthPageState extends State<SchoolAuthPage> {
+  final _username = TextEditingController(),
+      _password = TextEditingController();
+  bool _showWeb = false, _previewing = false;
+  @override
+  void initState() {
+    super.initState();
+    widget.session.addListener(_changed);
+    if (!widget.session.hasOpened) {
+      widget.session.open();
+    }
+  }
+
+  void _changed() {
+    if (!mounted) return;
+    setState(() {});
+    final draft = widget.session.pendingDraft;
+    if (draft != null && !_previewing) {
+      _previewing = true;
+      WidgetsBinding.instance.addPostFrameCallback((_) async {
+        if (!mounted) return;
+        await showModalBottomSheet<bool>(
+          context: context,
+          isScrollControlled: true,
+          showDragHandle: true,
+          builder: (_) =>
+              ImportPreview(draft: draft, controller: widget.controller),
+        );
+        widget.session.pendingDraft = null;
+        _previewing = false;
+      });
+    }
+  }
+
+  @override
+  void dispose() {
+    widget.session.removeListener(_changed);
+    _password.clear();
+    _username.clear();
+    _password.dispose();
+    _username.dispose();
+    super.dispose();
+  }
+
+  Future<void> _submit() async {
+    if (_username.text.trim().isEmpty || _password.text.isEmpty) {
+      ScaffoldMessenger.of(context)
+          .showSnackBar(const SnackBar(content: Text('请输入学号和密码')));
+      return;
+    }
+    try {
+      await widget.session.submitCredentials(
+        _username.text.trim(),
+        _password.text,
+      );
+    } finally {
+      _password.clear();
+      if (mounted) {
+        setState(() => _showWeb = true);
+      }
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final s = widget.session;
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text(
+          '学校认证',
+          style: TextStyle(fontSize: 20, fontWeight: FontWeight.w700),
+        ),
+        actions: [
+          IconButton(
+            tooltip: _showWeb ? '河畔登录界面' : '学校页面',
+            onPressed: () => setState(() => _showWeb = !_showWeb),
+            icon: Icon(
+              _showWeb ? Icons.person_outline : Icons.language_rounded,
+            ),
+          ),
+          IconButton(
+            tooltip: '打开学校课表',
+            onPressed: () {
+              setState(() => _showWeb = true);
+              s.openTimetable();
+            },
+            icon: const Icon(Icons.calendar_month_outlined),
+          ),
+        ],
+      ),
+      body: Column(
+        children: [
+          if (s.busy) const LinearProgressIndicator(minHeight: 2),
+          Container(
+            width: double.infinity,
+            padding: const EdgeInsets.all(13),
+            color: river.withValues(alpha: 0.07),
+            child: Text(
+              s.message,
+              style: const TextStyle(fontSize: 12, height: 1.5, color: ink),
+            ),
+          ),
+          Expanded(
+            child: _showWeb
+                ? WebViewWidget(controller: s.web)
+                : ListView(
+                    padding: const EdgeInsets.all(24),
+                    children: [
+                      const SizedBox(height: 20),
+                      const Icon(Icons.school_outlined, size: 48, color: river),
+                      const SizedBox(height: 20),
+                      const Text(
+                        '登录，连接你的每一天。',
+                        textAlign: TextAlign.center,
+                        style: TextStyle(
+                          fontSize: 23,
+                          fontWeight: FontWeight.w700,
+                        ),
+                      ),
+                      const SizedBox(height: 10),
+                      Text(
+                        '电子科技大学统一身份认证',
+                        textAlign: TextAlign.center,
+                        style: TextStyle(
+                          fontSize: 13,
+                          color: ink.withValues(alpha: 0.5),
+                        ),
+                      ),
+                      const SizedBox(height: 30),
+                      SurfaceCard(
+                        child: Column(
+                          children: [
+                            TextField(
+                              controller: _username,
+                              textInputAction: TextInputAction.next,
+                              autocorrect: false,
+                              decoration: const InputDecoration(
+                                labelText: '学号／工号',
+                                prefixIcon: Icon(Icons.person_outline),
+                              ),
+                            ),
+                            const SizedBox(height: 16),
+                            TextField(
+                              controller: _password,
+                              obscureText: true,
+                              enableSuggestions: false,
+                              autocorrect: false,
+                              decoration: const InputDecoration(
+                                labelText: '学校密码',
+                                prefixIcon: Icon(Icons.lock_outline),
+                              ),
+                              onSubmitted: (_) => _submit(),
+                            ),
+                            const SizedBox(height: 20),
+                            SizedBox(
+                              width: double.infinity,
+                              child: FilledButton(
+                                onPressed: !s.busy && s.formReady
+                                    ? _submit
+                                    : null,
+                                child: Text(s.busy ? '正在准备学校认证…' : '登录并打开课表'),
+                              ),
+                            ),
+                            const SizedBox(height: 10),
+                            TextButton(
+                              onPressed: () {
+                                _password.clear();
+                                setState(() => _showWeb = true);
+                                s.openAuthentication();
+                              },
+                              child: const Text('使用学校页面登录'),
+                            ),
+                          ],
+                        ),
+                      ),
+                      const SizedBox(height: 20),
+                      Text(
+                        '密码仅交给学校处理，不在河畔保存。需要验证码或其他验证时，将由学校页面继续处理。',
+                        textAlign: TextAlign.center,
+                        style: TextStyle(
+                          fontSize: 12,
+                          height: 1.7,
+                          color: ink.withValues(alpha: 0.45),
+                        ),
+                      ),
+                      const SizedBox(height: 14),
+                      Text(
+                        '学校课表识别待登录后联调；也可通过「我的」导入课表文件。',
+                        textAlign: TextAlign.center,
+                        style: TextStyle(
+                          fontSize: 11,
+                          height: 1.6,
+                          color: ink.withValues(alpha: 0.45),
+                        ),
+                      ),
+                    ],
+                  ),
+          ),
+        ],
+      ),
+    );
+  }
+}

mobile/lib/features/school/school_navigation_policy.dart

@@ -0,0 +1,19 @@
+class SchoolNavigationPolicy {
+  static bool canNavigate(Uri uri, {required bool isMainFrame}) => isMainFrame
+      ? isSchoolPage(uri)
+      : (uri.scheme == 'https' && uri.userInfo.isEmpty) ||
+            (uri.scheme == 'about' && uri.path == 'blank');
+  static bool _https(Uri uri) =>
+      uri.scheme == 'https' && uri.port == 443 && uri.userInfo.isEmpty;
+  static bool canInjectCredentials(Uri uri) =>
+      _https(uri) &&
+      uri.host == 'idas.uestc.edu.cn' &&
+      uri.path == '/authserver/login';
+  static bool isTimetable(Uri uri) =>
+      _https(uri) &&
+      uri.host == 'yjsjy.uestc.edu.cn' &&
+      uri.path == '/pyxx/pygl/xskbcx/index/1';
+  static bool isSchoolPage(Uri uri) =>
+      _https(uri) &&
+      const {'idas.uestc.edu.cn', 'yjsjy.uestc.edu.cn'}.contains(uri.host);
+}

mobile/lib/features/school/school_page_adapter.dart

@@ -0,0 +1,36 @@
+import '../../data/json_schedule_import.dart';
+import 'school_navigation_policy.dart';
+
+class UnsupportedSchoolLayout implements Exception {
+  @override
+  String toString() => '学校课表识别待联调，当前课表保持不变。';
+}
+
+class SchoolPageAdapter {
+  ImportDraft extract(String html, Uri source) {
+    // A real authenticated timetable fixture is required before registering a parser.
+    // Unknown HTML must never erase the student's last valid imported timetable.
+    throw UnsupportedSchoolLayout();
+  }
+}
+
+class SchoolReader {
+  SchoolReader(this.adapter);
+  final SchoolPageAdapter adapter;
+  Future<ImportDraft>? _pending;
+  bool get busy => _pending != null;
+  Future<ImportDraft> read(Uri origin, Future<String> Function() getHtml) {
+    if (_pending != null) return _pending!;
+    _pending = Future<ImportDraft>(() async {
+      try {
+        if (!SchoolNavigationPolicy.isTimetable(origin)) {
+          throw UnsupportedSchoolLayout();
+        }
+        return adapter.extract(await getHtml(), origin);
+      } finally {
+        _pending = null;
+      }
+    });
+    return _pending!;
+  }
+}

mobile/lib/features/school/school_session.dart

@@ -0,0 +1,254 @@
+import 'dart:convert';
+
+import 'package:flutter/foundation.dart';
+import 'package:webview_flutter/webview_flutter.dart';
+
+import '../../data/json_schedule_import.dart';
+import 'school_navigation_policy.dart';
+import 'school_page_adapter.dart';
+
+enum SchoolConnectionState {
+  signedOut,
+  authenticating,
+  connected,
+  expired,
+  unknown,
+}
+
+class SchoolSession extends ChangeNotifier {
+  SchoolSession() {
+    web = WebViewController()
+      ..setJavaScriptMode(JavaScriptMode.unrestricted)
+      ..setNavigationDelegate(
+        NavigationDelegate(
+          onNavigationRequest: (request) {
+            final uri = Uri.tryParse(request.url);
+            if (uri == null ||
+                !SchoolNavigationPolicy.canNavigate(
+                  uri,
+                  isMainFrame: request.isMainFrame,
+                )) {
+              message = '学校跳转到了其他地址，已停止自动交接登录信息。';
+              notifyListeners();
+              return NavigationDecision.prevent;
+            }
+            return NavigationDecision.navigate;
+          },
+          onPageStarted: (_) {
+            if (!hasOpened) {
+              return;
+            }
+            _loading = true;
+            formReady = false;
+            notifyListeners();
+          },
+          onPageFinished: _loaded,
+          onWebResourceError: (error) {
+            if (error.isForMainFrame == true) {
+              _loading = false;
+              message = '学校页面暂时未能加载，请检查网络或使用统一认证入口。';
+              notifyListeners();
+            }
+          },
+          onHttpError: (error) async {
+            final current = Uri.tryParse(await web.currentUrl() ?? '');
+            if (!hasOpened ||
+                error.request == null ||
+                error.request!.uri != current) {
+              return;
+            }
+            _loading = false;
+            message = '学校页面请求未完成，可稍后重试。';
+            notifyListeners();
+          },
+        ),
+      );
+  }
+  late final WebViewController web;
+  final _reader = SchoolReader(SchoolPageAdapter());
+  SchoolConnectionState connectionState = SchoolConnectionState.signedOut;
+  bool _loading = false,
+      _submitting = false,
+      hasOpened = false,
+      formReady = false;
+  bool get busy => _loading || _submitting || _reader.busy;
+  ImportDraft? pendingDraft;
+  String message = '请通过学校统一身份认证登录。';
+  String get statusLabel => switch (connectionState) {
+    SchoolConnectionState.signedOut => '未登录',
+    SchoolConnectionState.authenticating => '请在学校页面完成认证',
+    SchoolConnectionState.connected => '学校认证已确认',
+    SchoolConnectionState.expired => '学校登录已过期',
+    SchoolConnectionState.unknown => '学校页面已打开 · 课表识别待联调',
+  };
+  static final authUrl = Uri.parse(
+    'https://idas.uestc.edu.cn/authserver/login',
+  );
+  static final timetableUrl = Uri.parse(
+    'https://yjsjy.uestc.edu.cn/pyxx/pygl/xskbcx/index/1',
+  );
+  Future<void> open() => openTimetable();
+  Future<void> openTimetable() async {
+    hasOpened = true;
+    _loading = true;
+    pendingDraft = null;
+    message = '正在打开研究生课表页面…';
+    notifyListeners();
+    try {
+      await web.loadRequest(timetableUrl);
+    } catch (_) {
+      _loading = false;
+      message = '学校课表页面无法打开，请检查校园网络。';
+      notifyListeners();
+    }
+  }
+
+  Future<void> openAuthentication() async {
+    hasOpened = true;
+    _loading = true;
+    message = '正在准备学校认证…';
+    notifyListeners();
+    try {
+      await web.loadRequest(authUrl);
+    } catch (_) {
+      _loading = false;
+      message = '学校认证页面暂时不可用。';
+      notifyListeners();
+    }
+  }
+
+  static const _readyScript = """(() => {
+    if (location.origin !== 'https://idas.uestc.edu.cn' || location.pathname !== '/authserver/login') return false;
+    const f = document.querySelector('.login-main #pwdFromId');
+    if (!f || f.method.toLowerCase() !== 'post') return false;
+    const action = new URL(f.action, location.href);
+    return action.origin === location.origin && action.pathname === '/authserver/login'
+      && !!f.querySelector('#username') && !!f.querySelector('#password')
+      && !!f.querySelector('#saltPassword') && !!f.querySelector('#pwdEncryptSalt')
+      && !!f.querySelector('#login_submit') && typeof window.startLogin === 'function'
+      && typeof window.encryptPassword === 'function' && typeof window.checkUserCaptcha === 'function';
+  })()""";
+  bool _truth(Object value) => value == true || value.toString() == 'true';
+  Future<void> _loaded(String url) async {
+    if (!hasOpened) {
+      return;
+    }
+    _loading = false;
+    final uri = Uri.tryParse(url);
+    if (uri != null && SchoolNavigationPolicy.canInjectCredentials(uri)) {
+      connectionState = connectionState == SchoolConnectionState.connected
+          ? SchoolConnectionState.expired
+          : SchoolConnectionState.authenticating;
+      try {
+        formReady = _truth(
+          await web.runJavaScriptReturningResult(_readyScript),
+        );
+      } catch (_) {
+        formReady = false;
+      }
+      message = formReady ? '可以使用河畔界面登录；验证码会在学校页面完成。' : '请使用学校原页面完成认证。';
+    } else if (uri != null && SchoolNavigationPolicy.isTimetable(uri)) {
+      connectionState = SchoolConnectionState.unknown;
+      message = '已打开课表页面，正在核对课程结构。';
+      try {
+        pendingDraft = await readTimetable();
+        connectionState = SchoolConnectionState.connected;
+      } catch (error) {
+        message = error is UnsupportedSchoolLayout
+            ? error.toString()
+            : '课表读取未完成，已有课表保持不变。';
+      }
+    } else {
+      connectionState = SchoolConnectionState.unknown;
+      message = '可点击右上角日历打开学校课表。';
+    }
+    notifyListeners();
+  }
+
+  Future<void> submitCredentials(String username, String password) async {
+    if (busy) return;
+    _submitting = true;
+    message = '正在交接学校认证…';
+    notifyListeners();
+    try {
+      final url = Uri.tryParse(await web.currentUrl() ?? '');
+      if (url == null ||
+          !SchoolNavigationPolicy.canInjectCredentials(url) ||
+          !_truth(await web.runJavaScriptReturningResult(_readyScript))) {
+        throw StateError('学校表单尚未准备好，请使用学校页面登录');
+      }
+      final result = await web.runJavaScriptReturningResult('''(() => {
+        if (!($_readyScript)) return false;
+        const f = document.querySelector('.login-main #pwdFromId');
+        const u = f.querySelector('#username'), p = f.querySelector('#password');
+        u.value = ${jsonEncode(username)}; p.value = ${jsonEncode(password)};
+        p.removeAttribute('readonly');
+        u.dispatchEvent(new Event('input', {bubbles:true}));
+        p.dispatchEvent(new Event('input', {bubbles:true}));
+        window.checkUserCaptcha(); return true;
+      })()''');
+      if (!_truth(result)) throw StateError('学校表单已变化，请使用学校页面登录');
+      var settled = false;
+      for (var i = 0; i < 20; i++) {
+        if (_truth(
+          await web.runJavaScriptReturningResult(
+            '!!window.jQuery && window.jQuery.active === 0',
+          ),
+        )) {
+          settled = true;
+          break;
+        }
+        await Future<void>.delayed(const Duration(milliseconds: 200));
+      }
+      final current = Uri.tryParse(await web.currentUrl() ?? '');
+      if (!settled ||
+          current == null ||
+          !SchoolNavigationPolicy.canInjectCredentials(current)) {
+        message = '请在学校页面继续完成验证。';
+        return;
+      }
+      await web.runJavaScript('''(() => {
+        if (!($_readyScript)) return;
+        window.startLogin(document.querySelector('.login-main #pwdFromId #login_submit'));
+      })()''');
+      message = '已交给学校处理；如有验证码，请在学校页面完成。';
+    } catch (_) {
+      message = '登录交接未完成，请使用学校页面继续。';
+    } finally {
+      _submitting = false;
+      notifyListeners();
+    }
+  }
+
+  Future<ImportDraft> readTimetable() async {
+    final uri = Uri.tryParse(await web.currentUrl() ?? '');
+    if (uri == null) throw UnsupportedSchoolLayout();
+    return _reader.read(uri, () async {
+      final raw = await web.runJavaScriptReturningResult(
+        'JSON.stringify(document.documentElement.outerHTML)',
+      );
+      final value = raw is String ? raw : raw.toString();
+      try {
+        final decoded = jsonDecode(value);
+        return decoded is String ? decoded : value;
+      } catch (_) {
+        return value;
+      }
+    });
+  }
+
+  Future<void> logout() async {
+    hasOpened = false;
+    await WebViewCookieManager().clearCookies();
+    await web.clearCache();
+    await web.clearLocalStorage();
+    await web.loadHtmlString('<html></html>');
+    _loading = false;
+    hasOpened = false;
+    pendingDraft = null;
+    formReady = false;
+    connectionState = SchoolConnectionState.signedOut;
+    message = '已退出学校登录。';
+    notifyListeners();
+  }
+}

mobile/test/fixtures/school/README.md

@@ -0,0 +1,7 @@
+# 学校页面验证状态
+
+当前没有登录后的研究生课表样本，也没有以人工构造表格冒充学校样本。
+
+2026-10-12 已核对公开认证页面：密码表单位于 `.login-main #pwdFromId`，使用 username/passwordText 输入、saltPassword 隐藏加密字段、pwdEncryptSalt 与 startLogin/checkForm/encryptPassword 的学校原流程。自定义界面只填充此经过运行时检查的表单，并等待学校验证码检查结束后触发学校登录按钮。表单不匹配时回到学校页面。
+
+实际账号认证、验证码、研究生 SSO 跳转与课表识别还需本人设备登录验证。无需在聊天中提供账号密码。SchoolPageAdapter 当前拒绝全部未验证布局，保持已导入的离线课表不变。

mobile/test/school/navigation_policy_test.dart

@@ -0,0 +1,56 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:hepan_everyday/features/school/school_navigation_policy.dart';
+
+void main() {
+  test('secure captcha frames are allowed without authorizing credential injection', () {
+    final captcha = Uri.parse('https://captcha.example.test/challenge');
+    expect(
+      SchoolNavigationPolicy.canNavigate(captcha, isMainFrame: false),
+      isTrue,
+    );
+    expect(
+      SchoolNavigationPolicy.canNavigate(captcha, isMainFrame: true),
+      isFalse,
+    );
+    expect(SchoolNavigationPolicy.canInjectCredentials(captcha), isFalse);
+  });
+  test('credentials stay on the exact school HTTPS login endpoint', () {
+    expect(
+      SchoolNavigationPolicy.canInjectCredentials(
+        Uri.parse('https://idas.uestc.edu.cn/authserver/login?service=school'),
+      ),
+      isTrue,
+    );
+    for (final value in [
+      'http://idas.uestc.edu.cn/authserver/login',
+      'https://idas.uestc.edu.cn.evil.test/authserver/login',
+      'https://user@idas.uestc.edu.cn/authserver/login',
+      'https://idas.uestc.edu.cn:444/authserver/login',
+      'https://idas.uestc.edu.cn/other',
+    ]) {
+      expect(
+        SchoolNavigationPolicy.canInjectCredentials(Uri.parse(value)),
+        isFalse,
+        reason: value,
+      );
+    }
+  });
+  test('reading is limited to the supplied timetable path', () {
+    expect(
+      SchoolNavigationPolicy.isTimetable(
+        Uri.parse('https://yjsjy.uestc.edu.cn/pyxx/pygl/xskbcx/index/1'),
+      ),
+      isTrue,
+    );
+    expect(
+      SchoolNavigationPolicy.isTimetable(
+        Uri.parse('https://yjsjy.uestc.edu.cn/pyxx/login'),
+      ),
+      isFalse,
+    );
+    expect(
+      SchoolNavigationPolicy.isSchoolPage(Uri.parse('javascript:alert(1)')),
+      isFalse,
+    );
+  });
+}

mobile/test/school/school_page_adapter_test.dart

@@ -0,0 +1,70 @@
+import 'package:flutter_test/flutter_test.dart';
+
+import 'dart:async';
+
+import 'package:hepan_everyday/features/school/school_page_adapter.dart';
+
+void main() {
+  test(
+    'a rejected origin does not poison later legitimate page reading',
+    () async {
+      final reader = SchoolReader(SchoolPageAdapter());
+      await expectLater(
+        reader.read(
+          Uri.parse('https://idas.uestc.edu.cn/authserver/login'),
+          () async => 'x',
+        ),
+        throwsA(isA<UnsupportedSchoolLayout>()),
+      );
+      var reads = 0;
+      await expectLater(
+        reader.read(
+          Uri.parse('https://yjsjy.uestc.edu.cn/pyxx/pygl/xskbcx/index/1'),
+          () async {
+            reads++;
+            return 'unknown';
+          },
+        ),
+        throwsA(isA<UnsupportedSchoolLayout>()),
+      );
+      expect(reads, 1);
+    },
+  );
+  test('concurrent timetable reading obtains page content once', () async {
+    final reader = SchoolReader(SchoolPageAdapter());
+    final body = Completer<String>();
+    var reads = 0;
+    Future<String> getHtml() {
+      reads++;
+      return body.future;
+    }
+
+    final target = Uri.parse(
+      'https://yjsjy.uestc.edu.cn/pyxx/pygl/xskbcx/index/1',
+    );
+    final a = reader.read(target, getHtml), b = reader.read(target, getHtml);
+    final checks = Future.wait([
+      expectLater(a, throwsA(isA<UnsupportedSchoolLayout>())),
+      expectLater(b, throwsA(isA<UnsupportedSchoolLayout>())),
+    ]);
+    body.complete('unknown');
+    await checks;
+    expect(reads, 1);
+  });
+  test('unknown school markup never becomes an empty successful import', () {
+    final adapter = SchoolPageAdapter();
+    final target = Uri.parse(
+      'https://yjsjy.uestc.edu.cn/pyxx/pygl/xskbcx/index/1',
+    );
+    for (final html in [
+      '',
+      '<html>验证码</html>',
+      '<table><tr><td>课程名称</td></tr></table>',
+    ]) {
+      expect(
+        () => adapter.extract(html, target),
+        throwsA(isA<UnsupportedSchoolLayout>()),
+      );
+    }
+  });
+}