fix(content): 短剧保存时始终同步分集价格

docs/plans/2026-10-21-drama-free-episodes-sync.md

@@ -0,0 +1,30 @@
+# 2026-10-21 | 短剧保存免费集数同步分集
+
+## 目标
+
+后台短剧编辑改 `freeEpisodes` / `unlockCoin` 后，同步 `drama_episode.is_free` / `unlock_coin`，与定价页 `PriceService.save()` 规则一致。
+
+## 方案
+
+1. 抽出 `EpisodePriceSync.syncByDramaRule(dramaId, freeEpisodes, unlockCoin)`，供 `DramaService.update` 与 `PriceService.save` 共用。
+2. `DramaService.update` 在 `updateById` 后，仅当免费集数或解锁金币相对更新前有变化时调用同步。
+3. TDD：先写 `DramaServiceTest` 复现失败，再改实现转绿。
+
+## 范围
+
+- 仅 `fruitshorts-module-content`
+- 不改 Controller / VO / 契约 / 前端
+
+## 门禁
+
+```bash
+mvn -pl fruitshorts-module-content test -Dtest=DramaServiceTest
+mvn -pl fruitshorts-module-content test
+```
+
+## 分支 / 提交
+
+- `feature/drama-free-episodes-sync` ← `develop`
+- `test(content): 覆盖短剧免费集数同步分集价格`
+- `fix(content): 短剧保存免费集数时同步分集免费状态`
+- `merge --no-ff` 回 develop 并 push

docs/plans/2026-10-21-drama-price-sync-idempotent.md

@@ -0,0 +1,24 @@
+# 2026-10-21 | 短剧保存始终同步分集价格（幂等纠偏）
+
+## 背景
+
+承接 K104。短剧 `free_episodes=9` 重存后，分集 5~9 仍收费。
+
+## 根因
+
+`DramaService.update()` 仅在 `freeEpisodes` / `unlockCoin` 相对更新前有变化时调用 `EpisodePriceSync`。历史数据已漂移时，同值重存不触发同步。
+
+## 方案
+
+1. 测试：覆盖「规则字段未变、分集已漂移」仍纠正。
+2. `DramaService.update()`：每次保存都调用 `EpisodePriceSync.syncByDramaRule(drama)`。
+3. `EpisodePriceSync`：仅对有差异的行走 `updateById`（已具备，保持）。
+
+## 范围
+
+只改 `fruitshorts-module-content` 的 `DramaService` / `EpisodePriceSync` / `DramaServiceTest`。不改 Controller / VO / 契约 / 前端。
+
+## 提交
+
+1. `test(content): 覆盖免费集数未变但分集漂移的修复场景`
+2. `fix(content): 短剧保存时始终同步分集价格`

docs/plans/PROGRESS.md

@@ -24571,3 +24571,80 @@ OK_EXIT=0
 解读：拦截生效，干净 message 正常通过 commitlint。
 
 ---
+
+## 2026-10-21 | 短剧保存免费集数同步分集免费状态
+
+【Codex】根因：DramaService.update 只更新 drama，未同步 drama_episode.is_free/unlock_coin。
+抽出 EpisodePriceSync.syncByDramaRule，DramaService.update 与 PriceService.save 共用；仅 freeEpisodes/unlockCoin 变化时同步。
+
+### 门禁（原始输出摘录）
+
+```bash
+$ mvn -pl fruitshorts-module-content -am test -Dsurefire.failIfNoSpecifiedTests=false
+[INFO]  T E S T S
+[INFO] -------------------------------------------------------
+[INFO] Running com.fruitshorts.content.service.DramaServiceTest
+OpenJDK 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended
+WARNING: A Java agent has been loaded dynamically (/Users/jianghaifeng/.m2/repository/net/bytebuddy/byte-buddy-agent/1.14.13/byte-buddy-agent-1.14.13.jar)
+WARNING: If a serviceability tool is in use, please run with -XX:+EnableDynamicAgentLoading to hide this warning
+WARNING: If a serviceability tool is not in use, please run with -Djdk.instrument.traceUsage for more information
+WARNING: Dynamic loading of agents will be disallowed by default in a future release
+[INFO] Tests run: 4, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 1.126 s -- in com.fruitshorts.content.service.DramaServiceTest
+[INFO] 
+[INFO] Results:
+[INFO] 
+[INFO] Tests run: 4, Failures: 0, Errors: 0, Skipped: 0
+[INFO] 
+[INFO] ------------------------------------------------------------------------
+[INFO] Reactor Summary for fruitshorts 1.0.0-SNAPSHOT:
+[INFO] 
+[INFO] fruitshorts ........................................ SUCCESS [  0.001 s]
+[INFO] fruitshorts-common ................................. SUCCESS [  3.685 s]
+[INFO] fruitshorts-framework .............................. SUCCESS [ 31.492 s]
+[INFO] fruitshorts-module-system .......................... SUCCESS [  0.051 s]
+[INFO] fruitshorts-module-content ......................... SUCCESS [  4.451 s]
+[INFO] ------------------------------------------------------------------------
+[INFO] BUILD SUCCESS
+[INFO] ------------------------------------------------------------------------
+[INFO] Total time:  39.944 s
+[INFO] Finished at: 2026-10-21T22:35:43+08:00
+[INFO] ------------------------------------------------------------------------
+```
+
+解读：DramaServiceTest 4 条全过；module-content BUILD SUCCESS。
+
+### 提交 / 合并 / push
+
+```bash
+$ git log -2 --format=%B
+fix(content): 短剧保存免费集数时同步分集免费状态
+
+test(content): 覆盖短剧免费集数同步分集价格
+
+$ git log --oneline -4
+e92ec11 merge: 短剧保存免费集数同步分集免费状态
+4c4b53c fix(content): 短剧保存免费集数时同步分集免费状态
+d7f2266 test(content): 覆盖短剧免费集数同步分集价格
+979e6eb docs(plans): 登记 K100 提交 AI 痕迹已知偏差
+
+$ git push origin feature/drama-free-episodes-sync
+$ git push origin develop
+# develop 979e6eb..e92ec11
+```
+
+解读：作者 Zhou Weidong；无 Co-authored-by / AI 痕迹；develop 与 feature 均已 push。未启动/重启 8080/8081。停住等验收。
+
+---
+
+## 2026-10-21 短剧保存始终同步分集价格
+
+计划：`docs/plans/2026-10-21-drama-price-sync-idempotent.md`。
+同值重存也调用 `EpisodePriceSync.syncByDramaRule(drama)`，只更新有差异的分集。
+
+```
+$ mvn -pl fruitshorts-module-content -am test -Dtest=DramaServiceTest -Dsurefire.failIfNoSpecifiedTests=false
+[INFO] Tests run: 5, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 1.184 s -- in com.fruitshorts.content.service.DramaServiceTest
+[INFO] BUILD SUCCESS
+```
+
+解读：新增「规则未变但分集漂移」用例；原「已对齐则不写库」仍通过，但会查询分集。

fruitshorts-module-content/pom.xml

@@ -25,5 +25,10 @@
             <groupId>com.fruitshorts</groupId>
             <artifactId>fruitshorts-module-system</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 </project>

fruitshorts-module-content/src/main/java/com/fruitshorts/content/service/DramaService.java

@@ -42,6 +42,7 @@ public class DramaService {
     private final DramaEpisodeMapper dramaEpisodeMapper;
     private final DramaReviewRecordMapper dramaReviewRecordMapper;
     private final DramaCategoryService dramaCategoryService;
+    private final EpisodePriceSync episodePriceSync;
 
     public PageResult<DramaRespVO> page(DramaPageReqVO req) {
         List<String> dramaTypes = DramaMultiTagSupport.normalizeDramaTypes(req.getDramaTypes());
@@ -120,6 +121,7 @@ public class DramaService {
             drama.setViewCount(nonNegative(req.getHeat(), "热度"));
         }
         dramaMapper.updateById(drama);
+        episodePriceSync.syncByDramaRule(drama);
     }
 
     @Transactional(rollbackFor = Exception.class)

fruitshorts-module-content/src/main/java/com/fruitshorts/content/service/EpisodePriceSync.java

@@ -0,0 +1,74 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.content.service;
+
+import com.baomidou.mybatisplus.core.toolkit.Wrappers;
+import com.fruitshorts.content.dal.entity.Drama;
+import com.fruitshorts.content.dal.entity.DramaEpisode;
+import com.fruitshorts.content.dal.mapper.DramaEpisodeMapper;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * 按短剧免费集数规则同步分集 {@code is_free} / {@code unlock_coin}。
+ *
+ * <p>定价页与短剧编辑共用同一套规则，避免两处口径漂移。</p>
+ */
+@Component
+@RequiredArgsConstructor
+public class EpisodePriceSync {
+
+    private final DramaEpisodeMapper dramaEpisodeMapper;
+
+    /**
+     * 按短剧当前免费集数与解锁金币同步全部分集。
+     *
+     * @return 实际写库的分集数
+     */
+    public int syncByDramaRule(Drama drama) {
+        int freeEpisodes = drama.getFreeEpisodes() == null ? 0 : Math.max(0, drama.getFreeEpisodes());
+        int unlockCoin = drama.getUnlockCoin() == null ? 0 : Math.max(0, drama.getUnlockCoin());
+        return syncByDramaRule(drama.getId(), freeEpisodes, unlockCoin);
+    }
+
+    /**
+     * 全量同步某剧全部分集价格。
+     *
+     * <p>规则：{@code epNo > 0 && epNo <= freeEpisodes} 为免费且 coin=0，
+     * 否则收费且 coin={@code unlockCoin}。</p>
+     *
+     * @return 实际写库的分集数
+     */
+    public int syncByDramaRule(Long dramaId, int freeEpisodes, int unlockCoin) {
+        List<DramaEpisode> episodes = dramaEpisodeMapper.selectList(Wrappers.<DramaEpisode>lambdaQuery()
+                .eq(DramaEpisode::getDramaId, dramaId)
+                .orderByAsc(DramaEpisode::getEpNo));
+        int changed = 0;
+        for (DramaEpisode episode : episodes) {
+            int epNo = episode.getEpNo() == null ? 0 : episode.getEpNo();
+            int isFree = resolveIsFree(epNo, freeEpisodes);
+            int coin = resolveUnlockCoin(isFree, unlockCoin);
+            if (!Objects.equals(episode.getIsFree(), isFree)
+                    || !Objects.equals(episode.getUnlockCoin(), coin)) {
+                episode.setIsFree(isFree);
+                episode.setUnlockCoin(coin);
+                dramaEpisodeMapper.updateById(episode);
+                changed++;
+            }
+        }
+        return changed;
+    }
+
+    /** 集号落在免费区间内则为免费。 */
+    public static int resolveIsFree(int epNo, int freeEpisodes) {
+        return epNo > 0 && epNo <= freeEpisodes ? 1 : 0;
+    }
+
+    /** 免费集 coin 置 0，收费集用短剧解锁金币。 */
+    public static int resolveUnlockCoin(int isFree, int unlockCoin) {
+        return isFree == 1 ? 0 : unlockCoin;
+    }
+}

fruitshorts-module-content/src/main/java/com/fruitshorts/content/service/PriceService.java

@@ -32,6 +32,7 @@ public class PriceService {
     private final DramaService dramaService;
     private final DramaMapper dramaMapper;
     private final DramaEpisodeMapper dramaEpisodeMapper;
+    private final EpisodePriceSync episodePriceSync;
 
     /** 读取当前价格配置：后台定价页进入时先看现状再改。 */
     public PriceRespVO detail(Long dramaId) {
@@ -72,55 +73,13 @@ public class PriceService {
         drama.setUnlockCoin(unlockCoin);
         dramaMapper.updateById(drama);
 
+        int changed = episodePriceSync.syncByDramaRule(drama.getId(), freeEpisodes, unlockCoin);
+        changed += applyEpisodeOverrides(drama.getId(), unlockCoin, req);
+
         List<DramaEpisode> episodes = dramaEpisodeMapper.selectList(Wrappers.<DramaEpisode>lambdaQuery()
                 .eq(DramaEpisode::getDramaId, drama.getId())
                 .orderByAsc(DramaEpisode::getEpNo));
 
-        Map<Long, PriceSaveReqVO.EpisodePrice> overrides = new LinkedHashMap<>();
-        if (req.getEpisodes() != null) {
-            for (PriceSaveReqVO.EpisodePrice item : req.getEpisodes()) {
-                if (item != null && item.getEpisodeId() != null) {
-                    overrides.put(item.getEpisodeId(), item);
-                }
-            }
-        }
-
-        int changed = 0;
-        for (DramaEpisode episode : episodes) {
-            int epNo = episode.getEpNo() == null ? 0 : episode.getEpNo();
-            int isFree = epNo > 0 && epNo <= freeEpisodes ? 1 : 0;
-            int coin = isFree == 1 ? 0 : unlockCoin;
-
-            PriceSaveReqVO.EpisodePrice override = overrides.get(episode.getId());
-            Integer previewSeconds = null;
-            if (override != null) {
-                if (override.getIsFree() != null) {
-                    isFree = override.getIsFree() == 1 ? 1 : 0;
-                    coin = isFree == 1 ? 0 : unlockCoin;
-                }
-                if (isFree == 0 && override.getUnlockCoin() != null) {
-                    coin = Math.max(0, override.getUnlockCoin());
-                }
-                if (override.getPreviewSeconds() != null) {
-                    previewSeconds = Math.max(0, override.getPreviewSeconds());
-                }
-            }
-
-            boolean priceChanged = !Objects.equals(episode.getIsFree(), isFree)
-                    || !Objects.equals(episode.getUnlockCoin(), coin);
-            boolean previewChanged = previewSeconds != null
-                    && !Objects.equals(episode.getPreviewSeconds(), previewSeconds);
-            if (priceChanged || previewChanged) {
-                episode.setIsFree(isFree);
-                episode.setUnlockCoin(coin);
-                if (previewSeconds != null) {
-                    episode.setPreviewSeconds(previewSeconds);
-                }
-                dramaEpisodeMapper.updateById(episode);
-                changed++;
-            }
-        }
-
         PriceRespVO vo = new PriceRespVO();
         vo.setDramaId(drama.getId());
         vo.setFreeEpisodes(freeEpisodes);
@@ -139,4 +98,56 @@ public class PriceService {
         }).toList());
         return vo;
     }
+
+    /** 在整剧规则同步后再落单集覆盖（含试看秒数）。 */
+    private int applyEpisodeOverrides(Long dramaId, int unlockCoin, PriceSaveReqVO req) {
+        Map<Long, PriceSaveReqVO.EpisodePrice> overrides = new LinkedHashMap<>();
+        if (req.getEpisodes() != null) {
+            for (PriceSaveReqVO.EpisodePrice item : req.getEpisodes()) {
+                if (item != null && item.getEpisodeId() != null) {
+                    overrides.put(item.getEpisodeId(), item);
+                }
+            }
+        }
+        if (overrides.isEmpty()) {
+            return 0;
+        }
+        List<DramaEpisode> episodes = dramaEpisodeMapper.selectList(Wrappers.<DramaEpisode>lambdaQuery()
+                .eq(DramaEpisode::getDramaId, dramaId)
+                .orderByAsc(DramaEpisode::getEpNo));
+        int changed = 0;
+        for (DramaEpisode episode : episodes) {
+            PriceSaveReqVO.EpisodePrice override = overrides.get(episode.getId());
+            if (override == null) {
+                continue;
+            }
+            int isFree = episode.getIsFree() == null ? 0 : episode.getIsFree();
+            int coin = episode.getUnlockCoin() == null ? 0 : episode.getUnlockCoin();
+            Integer previewSeconds = null;
+            if (override.getIsFree() != null) {
+                isFree = override.getIsFree() == 1 ? 1 : 0;
+                coin = EpisodePriceSync.resolveUnlockCoin(isFree, unlockCoin);
+            }
+            if (isFree == 0 && override.getUnlockCoin() != null) {
+                coin = Math.max(0, override.getUnlockCoin());
+            }
+            if (override.getPreviewSeconds() != null) {
+                previewSeconds = Math.max(0, override.getPreviewSeconds());
+            }
+            boolean priceChanged = !Objects.equals(episode.getIsFree(), isFree)
+                    || !Objects.equals(episode.getUnlockCoin(), coin);
+            boolean previewChanged = previewSeconds != null
+                    && !Objects.equals(episode.getPreviewSeconds(), previewSeconds);
+            if (priceChanged || previewChanged) {
+                episode.setIsFree(isFree);
+                episode.setUnlockCoin(coin);
+                if (previewSeconds != null) {
+                    episode.setPreviewSeconds(previewSeconds);
+                }
+                dramaEpisodeMapper.updateById(episode);
+                changed++;
+            }
+        }
+        return changed;
+    }
 }

fruitshorts-module-content/src/test/java/com/fruitshorts/content/service/DramaServiceTest.java

@@ -0,0 +1,210 @@
+// Author: fruit.com.cn
+
+package com.fruitshorts.content.service;
+
+import com.baomidou.mybatisplus.core.MybatisConfiguration;
+import com.baomidou.mybatisplus.core.metadata.TableInfoHelper;
+import com.fruitshorts.content.dal.entity.Drama;
+import com.fruitshorts.content.dal.entity.DramaEpisode;
+import com.fruitshorts.content.dal.mapper.DramaEpisodeMapper;
+import com.fruitshorts.content.dal.mapper.DramaMapper;
+import com.fruitshorts.content.dal.mapper.DramaReviewRecordMapper;
+import com.fruitshorts.content.vo.DramaSaveReqVO;
+import org.apache.ibatis.builder.MapperBuilderAssistant;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+/**
+ * 短剧保存时免费集数 / 解锁金币须同步分集价格。
+ */
+class DramaServiceTest {
+
+    private static final long DRAMA_ID = 1001L;
+    private static final int UNLOCK_COIN = 60;
+
+    private DramaMapper dramaMapper;
+    private DramaEpisodeMapper dramaEpisodeMapper;
+    private DramaService dramaService;
+    private List<DramaEpisode> episodes;
+
+    @BeforeAll
+    static void initTableInfoCache() {
+        MapperBuilderAssistant assistant = new MapperBuilderAssistant(new MybatisConfiguration(), "");
+        TableInfoHelper.initTableInfo(assistant, Drama.class);
+        TableInfoHelper.initTableInfo(assistant, DramaEpisode.class);
+    }
+
+    @BeforeEach
+    void setUp() {
+        dramaMapper = mock(DramaMapper.class);
+        dramaEpisodeMapper = mock(DramaEpisodeMapper.class);
+        DramaReviewRecordMapper reviewRecordMapper = mock(DramaReviewRecordMapper.class);
+        DramaCategoryService categoryService = mock(DramaCategoryService.class);
+        EpisodePriceSync episodePriceSync = new EpisodePriceSync(dramaEpisodeMapper);
+        dramaService = new DramaService(
+                dramaMapper, dramaEpisodeMapper, reviewRecordMapper, categoryService, episodePriceSync);
+        episodes = new ArrayList<>();
+        given(dramaEpisodeMapper.selectList(any())).willAnswer(invocation -> List.copyOf(episodes));
+        given(dramaEpisodeMapper.updateById(any(DramaEpisode.class))).willAnswer(invocation -> {
+            DramaEpisode updated = invocation.getArgument(0);
+            for (int i = 0; i < episodes.size(); i++) {
+                if (episodes.get(i).getId().equals(updated.getId())) {
+                    episodes.set(i, updated);
+                    break;
+                }
+            }
+            return 1;
+        });
+    }
+
+    @Test
+    void should_mark_episodes_4_and_5_free_when_free_episodes_increase_from_3_to_5() {
+        givenExistingDrama(3, UNLOCK_COIN);
+        seedEpisodesAlignedToFree(3, 6);
+
+        dramaService.update(DRAMA_ID, saveReq(5, UNLOCK_COIN));
+
+        Map<Integer, DramaEpisode> byEpNo = episodeMap();
+        assertThat(byEpNo.get(4).getIsFree()).isEqualTo(1);
+        assertThat(byEpNo.get(4).getUnlockCoin()).isZero();
+        assertThat(byEpNo.get(5).getIsFree()).isEqualTo(1);
+        assertThat(byEpNo.get(5).getUnlockCoin()).isZero();
+        assertThat(byEpNo.get(6).getIsFree()).isZero();
+        assertThat(byEpNo.get(6).getUnlockCoin()).isEqualTo(UNLOCK_COIN);
+        verify(dramaEpisodeMapper, times(2)).updateById(any(DramaEpisode.class));
+    }
+
+    @Test
+    void should_mark_episodes_3_to_5_paid_when_free_episodes_decrease_from_5_to_2() {
+        givenExistingDrama(5, UNLOCK_COIN);
+        seedEpisodesAlignedToFree(5, 5);
+
+        dramaService.update(DRAMA_ID, saveReq(2, UNLOCK_COIN));
+
+        Map<Integer, DramaEpisode> byEpNo = episodeMap();
+        assertThat(byEpNo.get(3).getIsFree()).isZero();
+        assertThat(byEpNo.get(3).getUnlockCoin()).isEqualTo(UNLOCK_COIN);
+        assertThat(byEpNo.get(4).getIsFree()).isZero();
+        assertThat(byEpNo.get(4).getUnlockCoin()).isEqualTo(UNLOCK_COIN);
+        assertThat(byEpNo.get(5).getIsFree()).isZero();
+        assertThat(byEpNo.get(5).getUnlockCoin()).isEqualTo(UNLOCK_COIN);
+        verify(dramaEpisodeMapper, times(3)).updateById(any(DramaEpisode.class));
+    }
+
+    @Test
+    void should_skip_episode_updates_when_free_episodes_unchanged() {
+        givenExistingDrama(3, UNLOCK_COIN);
+        seedEpisodesAlignedToFree(3, 4);
+        AtomicInteger episodeUpdates = new AtomicInteger();
+        given(dramaEpisodeMapper.updateById(any(DramaEpisode.class))).willAnswer(invocation -> {
+            episodeUpdates.incrementAndGet();
+            return 1;
+        });
+
+        dramaService.update(DRAMA_ID, saveReq(3, UNLOCK_COIN));
+
+        assertThat(episodeUpdates.get()).isZero();
+        verify(dramaEpisodeMapper, times(1)).selectList(any());
+        verify(dramaEpisodeMapper, never()).updateById(any(DramaEpisode.class));
+    }
+
+    /**
+     * 历史漂移：短剧 freeEpisodes/unlockCoin 已是目标值，但分集 is_free 仍是旧规则。
+     * 同值重存必须纠偏，不能因「规则字段未变」短路跳过同步。
+     */
+    @Test
+    void should_correct_drifted_episode_is_free_when_free_episodes_and_unlock_coin_unchanged() {
+        givenExistingDrama(9, UNLOCK_COIN);
+        // 规则已是免费 9 集，分集仍按旧规则只免费到第 4 集（5~9 仍收费）
+        seedEpisodesAlignedToFree(4, 9);
+
+        dramaService.update(DRAMA_ID, saveReq(9, UNLOCK_COIN));
+
+        Map<Integer, DramaEpisode> byEpNo = episodeMap();
+        for (int epNo = 1; epNo <= 9; epNo++) {
+            assertThat(byEpNo.get(epNo).getIsFree()).isEqualTo(1);
+            assertThat(byEpNo.get(epNo).getUnlockCoin()).isZero();
+        }
+        verify(dramaEpisodeMapper, times(5)).updateById(any(DramaEpisode.class));
+    }
+
+    @Test
+    void should_not_fail_when_drama_has_no_episodes() {
+        givenExistingDrama(3, UNLOCK_COIN);
+        episodes.clear();
+
+        assertThatCode(() -> dramaService.update(DRAMA_ID, saveReq(5, UNLOCK_COIN)))
+                .doesNotThrowAnyException();
+        verify(dramaEpisodeMapper, never()).updateById(any(DramaEpisode.class));
+    }
+
+    private void givenExistingDrama(int freeEpisodes, int unlockCoin) {
+        Drama drama = new Drama();
+        drama.setId(DRAMA_ID);
+        drama.setTitle("测试短剧");
+        drama.setFreeEpisodes(freeEpisodes);
+        drama.setUnlockCoin(unlockCoin);
+        drama.setSubtitle("");
+        drama.setGenre("");
+        drama.setSynopsis("");
+        drama.setCoverUrl("");
+        drama.setTrailerUrl("");
+        drama.setLanguage("id-ID");
+        drama.setIsHot(0);
+        drama.setSort(0);
+        given(dramaMapper.selectById(DRAMA_ID)).willReturn(drama);
+        given(dramaMapper.updateById(any(Drama.class))).willReturn(1);
+    }
+
+    private void seedEpisodesAlignedToFree(int freeEpisodes, int total) {
+        episodes.clear();
+        for (int epNo = 1; epNo <= total; epNo++) {
+            DramaEpisode episode = new DramaEpisode();
+            episode.setId((long) epNo);
+            episode.setDramaId(DRAMA_ID);
+            episode.setEpNo(epNo);
+            episode.setTitle("第" + epNo + "集");
+            boolean free = epNo <= freeEpisodes;
+            episode.setIsFree(free ? 1 : 0);
+            episode.setUnlockCoin(free ? 0 : UNLOCK_COIN);
+            episodes.add(episode);
+        }
+    }
+
+    private DramaSaveReqVO saveReq(int freeEpisodes, int unlockCoin) {
+        DramaSaveReqVO req = new DramaSaveReqVO();
+        req.setTitle("测试短剧");
+        req.setFreeEpisodes(freeEpisodes);
+        req.setUnlockCoin(unlockCoin);
+        return req;
+    }
+
+    private Map<Integer, DramaEpisode> episodeMap() {
+        ArgumentCaptor<DramaEpisode> captor = ArgumentCaptor.forClass(DramaEpisode.class);
+        verify(dramaEpisodeMapper, org.mockito.Mockito.atLeastOnce()).updateById(captor.capture());
+        Map<Integer, DramaEpisode> updated = captor.getAllValues().stream()
+                .collect(Collectors.toMap(DramaEpisode::getEpNo, Function.identity(), (a, b) -> b));
+        for (DramaEpisode episode : episodes) {
+            updated.putIfAbsent(episode.getEpNo(), episode);
+        }
+        return updated;
+    }
+}