feat(test): Week 3 质量保障体系 — 55 新增测试 + CI/CD 流水线

前端第二批测试 (42 用例):
- AuthBloc: 16 用例 (启动恢复/登录/注册/角色选择/班级码/登出)
- HomeBloc: 8 用例 (数据加载/今日检测/心情统计/连续天数/离线容错)
- CalendarBloc: 10 用例 (月份切换/日期选择/视图模式/状态保持)
- MoodBloc: 8 用例 (统计加载/周期切换/API解析/错误处理)

后端 P0 单元测试 (13 用例):
- journal_service: 5 用例 (model_to_resp 转换/mood回退/weather回退/tags解析)
- sync_service: 8 用例 (冲突收集/DTO构造/序列化roundtrip/非冲突排除)

CI/CD:
- pr-check.yml: PR 触发 cargo fmt+check+clippy+test + flutter analyze+test
- main-merge.yml: main push 触发完整检查 + cargo audit 安全审计

测试统计: 前端 84 通过, 后端 73 通过 (全部通过)

app/test/features/home/bloc/home_bloc_test.dart

@@ -0,0 +1,273 @@
+// HomeBloc 单元测试
+//
+// 覆盖：首页数据加载、今日日记检查、心情统计、连续天数计算、离线容错
+// 使用 InMemoryJournalRepository 作为测试替身
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:nuanji_app/data/models/journal_element.dart';
+import 'package:nuanji_app/data/models/journal_entry.dart';
+import 'package:nuanji_app/data/repositories/journal_repository.dart';
+import 'package:nuanji_app/features/home/bloc/home_bloc.dart';
+
+void main() {
+  group('HomeBloc', () {
+    late HomeBloc bloc;
+    late InMemoryJournalRepository repo;
+
+    setUp(() {
+      repo = InMemoryJournalRepository();
+      bloc = HomeBloc(journalRepository: repo);
+    });
+
+    tearDown(() {
+      bloc.close();
+    });
+
+    // ===== 辅助 =====
+
+    /// 收集事件触发后的最终状态
+    Future<HomeState> dispatch(HomeEvent event) async {
+      bloc.add(event);
+      await Future<void>.delayed(const Duration(milliseconds: 50));
+      return bloc.state;
+    }
+
+    /// 创建测试日记条目
+    JournalEntry _makeEntry({
+      required String id,
+      required DateTime date,
+      Mood mood = Mood.happy,
+    }) {
+      return JournalEntry(
+        id: id,
+        authorId: 'user-1',
+        title: '测试日记',
+        date: date,
+        mood: mood,
+        createdAt: date,
+        updatedAt: date,
+      );
+    }
+
+    /// 获取当天零时的 DateTime
+    DateTime _today() {
+      final now = DateTime.now();
+      return DateTime(now.year, now.month, now.day);
+    }
+
+    /// 往前推 n 天的日期
+    DateTime _daysAgo(int n) {
+      return _today().subtract(Duration(days: n));
+    }
+
+    /// 向仓库批量添加日记
+    Future<void> _seed(List<JournalEntry> entries) async {
+      for (final e in entries) {
+        await repo.createJournal(e);
+      }
+    }
+
+    // ===== 1. HomeLoadData 成功 → HomeLoading → HomeLoaded with journals =====
+
+    test('HomeLoadData 成功时状态经过 HomeLoading 到达 HomeLoaded', () async {
+      final states = <HomeState>[];
+      final subscription = bloc.stream.listen(states.add);
+
+      await repo.createJournal(_makeEntry(
+        id: 'j-1',
+        date: _today(),
+      ));
+
+      bloc.add(const HomeLoadData());
+      await Future<void>.delayed(const Duration(milliseconds: 50));
+
+      subscription.cancel();
+
+      // 至少经历 HomeLoading → HomeLoaded
+      expect(states, contains(isA<HomeLoading>()));
+      expect(states.last, isA<HomeLoaded>());
+
+      final loaded = states.last as HomeLoaded;
+      expect(loaded.recentJournals.length, 1);
+      expect(loaded.recentJournals.first.id, 'j-1');
+    });
+
+    // ===== 2. HomeLoadData 有今日日记 → hasTodayEntry = true =====
+
+    test('HomeLoadData 有今日日记 → hasTodayEntry = true', () async {
+      await _seed([
+        _makeEntry(id: 'j-today', date: _today()),
+      ]);
+
+      final state = await dispatch(const HomeLoadData());
+      final loaded = state as HomeLoaded;
+
+      expect(loaded.hasTodayEntry, isTrue);
+    });
+
+    // ===== 3. HomeLoadData 无今日日记 → hasTodayEntry = false =====
+
+    test('HomeLoadData 无今日日记 → hasTodayEntry = false', () async {
+      await _seed([
+        _makeEntry(id: 'j-yesterday', date: _daysAgo(1)),
+      ]);
+
+      final state = await dispatch(const HomeLoadData());
+      final loaded = state as HomeLoaded;
+
+      expect(loaded.hasTodayEntry, isFalse);
+    });
+
+    // ===== 4. HomeLoadData 计算最常用心情 topMood → happy(3次) vs calm(1次) =====
+
+    test('HomeLoadData topMood 为出现次数最多的心情', () async {
+      await _seed([
+        _makeEntry(id: 'j-1', date: _daysAgo(0), mood: Mood.happy),
+        _makeEntry(id: 'j-2', date: _daysAgo(1), mood: Mood.happy),
+        _makeEntry(id: 'j-3', date: _daysAgo(2), mood: Mood.happy),
+        _makeEntry(id: 'j-4', date: _daysAgo(3), mood: Mood.calm),
+      ]);
+
+      final state = await dispatch(const HomeLoadData());
+      final loaded = state as HomeLoaded;
+
+      expect(loaded.topMood, Mood.happy);
+    });
+
+    // ===== 5. HomeLoadData 计算连续天数 streakDays（连续 3 天）=====
+
+    test('HomeLoadData streakDays 计算从今天开始的连续天数', () async {
+      // 今天、昨天、前天 — 连续 3 天
+      await _seed([
+        _makeEntry(id: 'j-today', date: _daysAgo(0)),
+        _makeEntry(id: 'j-yesterday', date: _daysAgo(1)),
+        _makeEntry(id: 'j-day-before', date: _daysAgo(2)),
+        // 4 天前（中断连续）
+        _makeEntry(id: 'j-old', date: _daysAgo(4)),
+      ]);
+
+      final state = await dispatch(const HomeLoadData());
+      final loaded = state as HomeLoaded;
+
+      expect(loaded.streakDays, 3);
+    });
+
+    // ===== 6. HomeLoadData 失败 → HomeLoaded (空数据，离线友好) =====
+
+    test('HomeLoadData 失败时返回空 HomeLoaded（离线友好）', () async {
+      // 使用一个会在 getJournals 时抛异常的仓库
+      final failingRepo = _FailingJournalRepository();
+      final failingBloc = HomeBloc(journalRepository: failingRepo);
+
+      final state = await _dispatchOn(failingBloc, const HomeLoadData());
+
+      expect(state, isA<HomeLoaded>());
+      final loaded = state as HomeLoaded;
+      expect(loaded.recentJournals, isEmpty);
+      expect(loaded.hasTodayEntry, isFalse);
+      expect(loaded.topMood, isNull);
+      expect(loaded.streakDays, 0);
+
+      failingBloc.close();
+    });
+
+    // ===== 7. HomeRefresh → 触发 HomeLoadData =====
+
+    test('HomeRefresh 触发重新加载（经过 Loading → Loaded）', () async {
+      final states = <HomeState>[];
+      final subscription = bloc.stream.listen(states.add);
+
+      await repo.createJournal(_makeEntry(
+        id: 'j-refresh',
+        date: _today(),
+      ));
+
+      bloc.add(const HomeRefresh());
+      await Future<void>.delayed(const Duration(milliseconds: 50));
+
+      subscription.cancel();
+
+      // HomeRefresh 内部 add(HomeLoadData)，所以应有 Loading → Loaded
+      expect(states, contains(isA<HomeLoading>()));
+      expect(states.last, isA<HomeLoaded>());
+
+      final loaded = states.last as HomeLoaded;
+      expect(loaded.recentJournals.length, 1);
+    });
+
+    // ===== 8. HomeLoadData 空数据 → HomeLoaded with defaults =====
+
+    test('HomeLoadData 空数据时返回默认 HomeLoaded', () async {
+      // 仓库中不添加任何日记
+      final state = await dispatch(const HomeLoadData());
+      final loaded = state as HomeLoaded;
+
+      expect(loaded.recentJournals, isEmpty);
+      expect(loaded.hasTodayEntry, isFalse);
+      expect(loaded.topMood, isNull);
+      expect(loaded.streakDays, 0);
+    });
+  });
+}
+
+// ===== 测试辅助：总是抛出异常的仓库 =====
+
+/// 模拟仓库失败场景，用于测试离线容错
+class _FailingJournalRepository implements JournalRepository {
+  @override
+  Future<List<JournalEntry>> getJournals({
+    DateTime? dateFrom,
+    DateTime? dateTo,
+    int? page,
+    int? pageSize,
+  }) async {
+    throw Exception('网络不可用');
+  }
+
+  @override
+  Future<JournalEntry?> getJournal(String id) async {
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<JournalEntry> createJournal(JournalEntry entry) async {
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<JournalEntry> updateJournal(JournalEntry entry) async {
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<void> deleteJournal(String id) async {
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<List<JournalElement>> getElements(String journalId) async {
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<JournalElement> addElement(JournalElement element) async {
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<JournalElement> updateElement(JournalElement element) async {
+    throw UnimplementedError();
+  }
+
+  @override
+  Future<void> removeElement(String elementId) async {
+    throw UnimplementedError();
+  }
+}
+
+/// 在指定 bloc 上触发事件并等待处理完毕
+Future<HomeState> _dispatchOn(HomeBloc bloc, HomeEvent event) async {
+  bloc.add(event);
+  await Future<void>.delayed(const Duration(milliseconds: 50));
+  return bloc.state;
+}