test(app): 前端第一批测试 — EditorBloc 19用例 + JournalElement 11用例 + InMemoryRepo 12用例

添加 mocktail 测试依赖 + 字体文件占位
总计 42 测试通过，覆盖工具/笔画/元素/撤销/重做/序列化/乐观锁/CRUD

app/test/data/repositories/in_memory_journal_repository_test.dart

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+// InMemoryJournalRepository 单元测试
+//
+// 覆盖：CRUD 操作、乐观锁冲突、软删除、元素管理、clearAll
+
+import 'dart:math';
+
+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';
+
+void main() {
+  group('InMemoryJournalRepository', () {
+    late InMemoryJournalRepository repo;
+
+    setUp(() {
+      repo = InMemoryJournalRepository();
+    });
+
+    // ===== 辅助方法 =====
+
+    JournalEntry _createEntry({String id = 'j-1', String title = '测试日记'}) {
+      return JournalEntry(
+        id: id,
+        authorId: 'user-1',
+        title: title,
+        date: DateTime(2026, 6, 1),
+        mood: Mood.happy,
+        weather: Weather.sunny,
+        tags: const [],
+        isPrivate: false,
+        sharedToClass: false,
+        version: 1,
+        createdAt: DateTime.now(),
+        updatedAt: DateTime.now(),
+      );
+    }
+
+    // ===== 创建 =====
+
+    test('创建日记', () async {
+      final entry = _createEntry();
+      final created = await repo.createJournal(entry);
+
+      expect(created.id, entry.id);
+      expect(created.title, '测试日记');
+      expect(repo.journalCount, 1);
+    });
+
+    // ===== 读取 =====
+
+    test('获取日记', () async {
+      final entry = _createEntry();
+      await repo.createJournal(entry);
+
+      final fetched = await repo.getJournal('j-1');
+
+      expect(fetched, isNotNull);
+      expect(fetched!.title, '测试日记');
+    });
+
+    test('获取不存在的日记返回 null', () async {
+      final fetched = await repo.getJournal('non-existent');
+      expect(fetched, isNull);
+    });
+
+    test('获取日记列表', () async {
+      await repo.createJournal(_createEntry(id: 'j-1'));
+      await repo.createJournal(_createEntry(id: 'j-2'));
+
+      final list = await repo.getJournals();
+
+      expect(list.length, 2);
+    });
+
+    test('空仓库返回空列表', () async {
+      final list = await repo.getJournals();
+      expect(list, isEmpty);
+    });
+
+    // ===== 更新 =====
+
+    test('更新日记标题', () async {
+      await repo.createJournal(_createEntry());
+      final existing = (await repo.getJournal('j-1'))!;
+
+      final updated = await repo.updateJournal(
+        existing.copyWith(title: '更新后的标题'),
+      );
+
+      expect(updated.title, '更新后的标题');
+      expect(updated.version, 2);
+
+      final refetched = (await repo.getJournal('j-1'))!;
+      expect(refetched.title, '更新后的标题');
+      expect(refetched.version, 2);
+    });
+
+    test('乐观锁版本冲突抛出异常', () async {
+      await repo.createJournal(_createEntry());
+      final v1 = (await repo.getJournal('j-1'))!;
+
+      // 先更新一次 → v2
+      await repo.updateJournal(v1.copyWith(title: 'v2'));
+
+      // 再用 v1 更新 → 应抛 StateError
+      expect(
+        () => repo.updateJournal(v1.copyWith(title: 'conflict')),
+        throwsA(isA<StateError>()),
+      );
+    });
+
+    // ===== 删除 =====
+
+    test('软删除日记', () async {
+      await repo.createJournal(_createEntry());
+      await repo.deleteJournal('j-1');
+
+      final fetched = await repo.getJournal('j-1');
+      expect(fetched, isNull);
+    });
+
+    // ===== 元素 =====
+
+    test('添加元素', () async {
+      await repo.createJournal(_createEntry());
+      final element = JournalElement.createText(
+        journalId: 'j-1',
+        text: '测试文字',
+        position: Offset.zero,
+      );
+
+      final added = await repo.addElement(element);
+      expect(added.journalId, 'j-1');
+      expect(repo.elementCount, 1);
+    });
+
+    test('获取元素列表（按 journalId 过滤）', () async {
+      await repo.createJournal(_createEntry(id: 'j-1'));
+      await repo.createJournal(_createEntry(id: 'j-2'));
+      await repo.addElement(JournalElement.createText(
+        journalId: 'j-1', text: '文字1', position: Offset.zero,
+      ));
+      await repo.addElement(JournalElement.createSticker(
+        journalId: 'j-1', emoji: '🌸', position: const Offset(50, 50),
+      ));
+      await repo.addElement(JournalElement.createText(
+        journalId: 'j-2', text: '文字2', position: Offset.zero,
+      ));
+
+      final elementsJ1 = await repo.getElements('j-1');
+      final elementsJ2 = await repo.getElements('j-2');
+
+      expect(elementsJ1.length, 2);
+      expect(elementsJ2.length, 1);
+    });
+
+    test('删除元素', () async {
+      await repo.createJournal(_createEntry());
+      final element = JournalElement.createText(
+        journalId: 'j-1', text: '待删除', position: Offset.zero,
+      );
+      await repo.addElement(element);
+
+      await repo.removeElement(element.id);
+
+      expect(repo.elementCount, 0);
+      final elements = await repo.getElements('j-1');
+      expect(elements, isEmpty);
+    });
+
+    // ===== clearAll =====
+
+    test('clearAll 清空所有数据', () async {
+      await repo.createJournal(_createEntry(id: 'j-1'));
+      await repo.createJournal(_createEntry(id: 'j-2'));
+      await repo.addElement(JournalElement.createText(
+        journalId: 'j-1', text: '文字', position: Offset.zero,
+      ));
+
+      repo.clearAll();
+
+      expect(repo.journalCount, 0);
+      expect(repo.elementCount, 0);
+      expect(await repo.getJournals(), isEmpty);
+    });
+  });
+}