fix(book): 添加小说存在性校验

- 在保存评论前校验小说是否存在

src/main/java/io/github/xxyopen/novel/core/common/constant/ErrorCodeEnum.java

@@ -99,6 +99,11 @@ public enum ErrorCodeEnum {
      */
     USER_COMMENTED("A2001", "用户已发表评论"),
 
+    /**
+     * 小说不存在
+     */
+    BOOK_NOT_FOUND("A2002", "小说ID不存在"),
+
     /**
      * 作家发布异常
      */

src/main/java/io/github/xxyopen/novel/service/impl/BookServiceImpl.java

@@ -230,6 +230,11 @@ public class BookServiceImpl implements BookService {
     @Override
     public RestResp<Void> saveComment(
         @Key(expr = "#{userId + '::' + bookId}") UserCommentReqDto dto) {
+        // 校验书籍是否存在
+        BookInfo bookInfo = bookInfoMapper.selectById(dto.getBookId());
+        if (bookInfo == null) {
+            return RestResp.fail(ErrorCodeEnum.BOOK_NOT_FOUND);
+        }
         // 校验用户是否已发表评论
         QueryWrapper<BookComment> queryWrapper = new QueryWrapper<>();
         queryWrapper.eq(DatabaseConsts.BookCommentTable.COLUMN_USER_ID, dto.getUserId())