refact : reply 서비스, 컨트롤러 comment로 병합

 - 테스트를 진행하면서 분리되어 있던 대댓글 기능을 CommentController, CommentService로 통합함.
#41

src/main/java/com/project/minibacktesting_be/controller/CommentController.java

@@ -55,4 +55,16 @@ public void deleteComment(@PathVariable Long commentId,
                 userDetails.getUser().getId(),commentId);
         commentService.deleteComment(commentId, userDetails);
     }
+
+
+
+    // 대댓글 작성하기
+    @PostMapping("/comments/{commentId}")
+    public CommentResponseDto registerReply(@PathVariable Long commentId,
+                                            @RequestBody CommentRequestDto requestDto,
+                                            @AuthenticationPrincipal UserDetailsImpl userDetails){
+        log.info("대댓글 작성하기 userId : {} commentId : {}",
+                userDetails.getUser().getId(),commentId);
+        return commentService.registerReply(commentId, requestDto, userDetails);
+    }
 }

src/main/java/com/project/minibacktesting_be/service/CommentService.java

@@ -113,4 +113,15 @@ public void deleteComment(Long commentId, UserDetailsImpl userDetails) {
         commentRepository.deleteAll(comments);
         commentRepository.delete(comment);
     }
+
+    public CommentResponseDto registerReply(Long commentId, CommentRequestDto requestDto, UserDetailsImpl userDetails) {
+        Comment comment =  PresentCheck.commentIsPresentCheck(commentId, commentRepository);
+        Comment reply = Comment.commentBuilder()
+                .portfolio(comment.getPortfolio())
+                .user(userDetails.getUser())
+                .content(requestDto.getContent())
+                .parentComment(comment)
+                .build();
+        return CommentResponseDto.builder().commentId(commentRepository.save(reply).getId()).build();
+    }
 }