From 330def7e1c696380162f4fda1ac559720870c311 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 21:01:20 +0900
Subject: [PATCH 01/37] =?UTF-8?q?docs=20step1=20=EC=9A=94=EA=B5=AC?=
 =?UTF-8?q?=EC=82=AC=ED=95=AD=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step1.md | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
 create mode 100644 docs/step1.md

diff --git a/docs/step1.md b/docs/step1.md
new file mode 100644
index 0000000000..d042a9e7c0
--- /dev/null
+++ b/docs/step1.md
@@ -0,0 +1,15 @@
+## 요구사항
+
+- 질문 데이터를 완전히 삭제하는 것이 아니라 데이터의 상태를 삭제 상태(deleted - boolean type)로 변경한다.
+- 로그인 상요자와 질문한 사람이 같은 경우 삭제 가능하다.
+- 답변이 없는 경우 삭제가 가능하다.
+- 질문자와 답변 글의 모든 답변자가 같은 경우 삭제가 가능하다.
+- 질문자를 삭제할 때 답변 또한 삭제해야 하며, 답변의 삭제 또한 삭제 상태(deleted)를 변경한다.
+- 질문자와 답변자가 다른 경우 답변을 삭제할 수 없다.
+- 질문과 답변 삭제 이력에 대한 정보를 DeleteHistory를 활용해 넘긴다.
+
+## 리팩터링 요구사항
+- nextstep.qna.service.QnaService의 deleteQuestion()는 앞의 질문 삭제 기능을 구현한 코드이다. 이 메소드는 단위 테스트하기 어려운 코드와 단위 테스트 가능한 코드가 섞여 있다.
+- QnaService의 deleteQuestion() 메서드에 단위 테스트 가능한 코드(핵심 비지니스 로직)를 도메인 모델 객체에 구현한다.
+- QnaService의 비지니스 로직을 도메인 모델로 이동하는 리팩터링을 진행할 때 TDD로 구현한다.
+- QnaService의 deleteQuestion() 메서드에 대한 단위 테스트는 src/test/java 폴더 nextstep.qna.service.QnaServiceTest이다. 도메인 모델로 로직을 이동한 후에도 QnaServiceTest의 모든 테스트는 통과해야 한다.
\ No newline at end of file

From 45603af6c519c819d5b30b3d0ff2beacd1bc3d46 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 21:16:22 +0900
Subject: [PATCH 02/37] =?UTF-8?q?test=20=EC=A7=88=EB=AC=B8=20=EA=B6=8C?=
 =?UTF-8?q?=ED=95=9C=20=EA=B2=80=EC=A6=9D=20=ED=85=8C=EC=8A=A4=ED=8A=B8=20?=
 =?UTF-8?q?=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../java/nextstep/qna/domain/QuestionTest.java    | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/test/java/nextstep/qna/domain/QuestionTest.java b/src/test/java/nextstep/qna/domain/QuestionTest.java
index 3b87823963..15f57d1ceb 100644
--- a/src/test/java/nextstep/qna/domain/QuestionTest.java
+++ b/src/test/java/nextstep/qna/domain/QuestionTest.java
@@ -1,8 +1,23 @@
 package nextstep.qna.domain;
 
+import nextstep.qna.CannotDeleteException;
 import nextstep.users.domain.NsUserTest;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
 
 public class QuestionTest {
     public static final Question Q1 = new Question(NsUserTest.JAVAJIGI, "title1", "contents1");
     public static final Question Q2 = new Question(NsUserTest.SANJIGI, "title2", "contents2");
+
+    @Test
+    void 질문_작성자가_자신일_경우_예외가_발생하지_않는다() throws CannotDeleteException {
+        Q1.validateOwnership(NsUserTest.JAVAJIGI);
+    }
+
+    @Test
+    void 질문_작성자가_타인일_경우_예외가_발생한다() {
+        Assertions.assertThatThrownBy(() -> Q1.validateOwnership(NsUserTest.SANJIGI))
+                .isInstanceOf(CannotDeleteException.class)
+                .hasMessageContaining("질문을 삭제할 권한이 없습니다.");
+    }
 }

From 7bc74cad52dcf2daaa8bdf0b3c338433be6de360 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 21:17:29 +0900
Subject: [PATCH 03/37] =?UTF-8?q?refactor=20=EC=A7=88=EB=AC=B8=EC=9D=98=20?=
 =?UTF-8?q?=EC=9E=91=EC=84=B1=EC=9E=90=EA=B0=80=20=EB=B3=B8=EC=9D=B8?=
 =?UTF-8?q?=EC=9D=B8=EC=A7=80=20=EA=B2=80=EC=82=AC=ED=95=98=EB=8A=94=20?=
 =?UTF-8?q?=EA=B8=B0=EB=8A=A5=20=EC=A7=88=EB=AC=B8=20=ED=81=B4=EB=9E=98?=
 =?UTF-8?q?=EC=8A=A4=EB=A1=9C=20=EC=9D=B4=EB=8F=99?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/nextstep/qna/domain/Question.java    | 9 ++++++++-
 src/main/java/nextstep/qna/service/QnAService.java | 4 +---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/main/java/nextstep/qna/domain/Question.java b/src/main/java/nextstep/qna/domain/Question.java
index b623c52c76..9c0b5bcb8a 100644
--- a/src/main/java/nextstep/qna/domain/Question.java
+++ b/src/main/java/nextstep/qna/domain/Question.java
@@ -1,5 +1,6 @@
 package nextstep.qna.domain;
 
+import nextstep.qna.CannotDeleteException;
 import nextstep.users.domain.NsUser;
 
 import java.time.LocalDateTime;
@@ -37,6 +38,12 @@ public Question(Long id, NsUser writer, String title, String contents) {
         this.contents = contents;
     }
 
+    public void validateOwnership(NsUser loginUser) throws CannotDeleteException {
+        if (!isOwner(loginUser)) {
+            throw new CannotDeleteException("질문을 삭제할 권한이 없습니다.");
+        }
+    }
+
     public Long getId() {
         return id;
     }
@@ -68,7 +75,7 @@ public void addAnswer(Answer answer) {
         answers.add(answer);
     }
 
-    public boolean isOwner(NsUser loginUser) {
+    private boolean isOwner(NsUser loginUser) {
         return writer.equals(loginUser);
     }
 
diff --git a/src/main/java/nextstep/qna/service/QnAService.java b/src/main/java/nextstep/qna/service/QnAService.java
index 5741c84d65..4bf1cb6e63 100644
--- a/src/main/java/nextstep/qna/service/QnAService.java
+++ b/src/main/java/nextstep/qna/service/QnAService.java
@@ -26,9 +26,7 @@ public class QnAService {
     @Transactional
     public void deleteQuestion(NsUser loginUser, long questionId) throws CannotDeleteException {
         Question question = questionRepository.findById(questionId).orElseThrow(NotFoundException::new);
-        if (!question.isOwner(loginUser)) {
-            throw new CannotDeleteException("질문을 삭제할 권한이 없습니다.");
-        }
+        question.validateOwnership(loginUser);
 
         List<Answer> answers = question.getAnswers();
         for (Answer answer : answers) {

From 90f69fa818daa90d07b3db712eec8b8796155a4f Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 22:33:36 +0900
Subject: [PATCH 04/37] =?UTF-8?q?test=20=EB=8B=B5=EB=B3=80=20=EA=B2=80?=
 =?UTF-8?q?=EC=A6=9D=20=ED=85=8C=EC=8A=A4=ED=8A=B8=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/test/java/nextstep/qna/domain/AnswerTest.java | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/test/java/nextstep/qna/domain/AnswerTest.java b/src/test/java/nextstep/qna/domain/AnswerTest.java
index 8e80ffb429..6558877335 100644
--- a/src/test/java/nextstep/qna/domain/AnswerTest.java
+++ b/src/test/java/nextstep/qna/domain/AnswerTest.java
@@ -1,8 +1,23 @@
 package nextstep.qna.domain;
 
+import nextstep.qna.CannotDeleteException;
 import nextstep.users.domain.NsUserTest;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
 
 public class AnswerTest {
     public static final Answer A1 = new Answer(NsUserTest.JAVAJIGI, QuestionTest.Q1, "Answers Contents1");
     public static final Answer A2 = new Answer(NsUserTest.SANJIGI, QuestionTest.Q1, "Answers Contents2");
+
+    @Test
+    void 답변_작성자가_자신일_경우_예외가_발생하지_않는다() throws CannotDeleteException {
+        A1.validateOwnership(NsUserTest.JAVAJIGI);
+    }
+
+    @Test
+    void 답변_작성자가_타인일_경우_예외가_발생한다() {
+        Assertions.assertThatThrownBy(() -> A1.validateOwnership(NsUserTest.SANJIGI))
+                .isInstanceOf(CannotDeleteException.class)
+                .hasMessageContaining("다른 사람이 쓴 답변이 있어 삭제할 수 없습니다.");
+    }
 }

From 1434fba01cffb533abd3937af812f9a68feb5b4e Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 22:35:18 +0900
Subject: [PATCH 05/37] =?UTF-8?q?refactor=20=EB=8B=B5=EB=B3=80=20=EC=9E=91?=
 =?UTF-8?q?=EC=84=B1=EC=9E=90=EB=A5=BC=20=EA=B2=80=EC=A6=9D=ED=95=98?=
 =?UTF-8?q?=EB=8A=94=20=EA=B8=B0=EB=8A=A5=20Answer=20=ED=81=B4=EB=9E=98?=
 =?UTF-8?q?=EC=8A=A4=EB=A1=9C=20=EC=9D=B4=EB=8F=99?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/nextstep/qna/domain/Answer.java | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/main/java/nextstep/qna/domain/Answer.java b/src/main/java/nextstep/qna/domain/Answer.java
index cf681811e7..d6f8f262c5 100644
--- a/src/main/java/nextstep/qna/domain/Answer.java
+++ b/src/main/java/nextstep/qna/domain/Answer.java
@@ -1,5 +1,6 @@
 package nextstep.qna.domain;
 
+import nextstep.qna.CannotDeleteException;
 import nextstep.qna.NotFoundException;
 import nextstep.qna.UnAuthorizedException;
 import nextstep.users.domain.NsUser;
@@ -43,6 +44,12 @@ public Answer(Long id, NsUser writer, Question question, String contents) {
         this.contents = contents;
     }
 
+    public void validateOwnership(NsUser loginUser) throws CannotDeleteException {
+        if (!isOwner(loginUser)) {
+            throw new CannotDeleteException("다른 사람이 쓴 답변이 있어 삭제할 수 없습니다.");
+        }
+    }
+
     public Long getId() {
         return id;
     }

From 2104de2f455bfc0743d5abedefe6d7d237bf5555 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 22:36:24 +0900
Subject: [PATCH 06/37] =?UTF-8?q?feat=20Answer=EC=9D=98=20=EC=82=AD?=
 =?UTF-8?q?=EC=A0=9C=20=EC=83=81=ED=83=9C=EB=A5=BC=20true=EB=A1=9C=20?=
 =?UTF-8?q?=EB=A7=8C=EB=93=A4=EA=B3=A0=20DeleteHistory=EB=A5=BC=20?=
 =?UTF-8?q?=EB=B0=98=ED=99=98=ED=95=98=EB=8A=94=20=EA=B8=B0=EB=8A=A5=20?=
 =?UTF-8?q?=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/nextstep/qna/domain/Answer.java | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/main/java/nextstep/qna/domain/Answer.java b/src/main/java/nextstep/qna/domain/Answer.java
index d6f8f262c5..624e4d5519 100644
--- a/src/main/java/nextstep/qna/domain/Answer.java
+++ b/src/main/java/nextstep/qna/domain/Answer.java
@@ -50,6 +50,11 @@ public void validateOwnership(NsUser loginUser) throws CannotDeleteException {
         }
     }
 
+    public DeleteHistory delete() {
+        deleted = true;
+        return DeleteHistory.ofAnswer(this);
+    }
+
     public Long getId() {
         return id;
     }

From 8c94a3d99ac18eb0317e6a7f67a4b3f911a94bd6 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 22:36:56 +0900
Subject: [PATCH 07/37] =?UTF-8?q?refactor=20Answer=20=EC=9D=BC=EA=B8=89?=
 =?UTF-8?q?=EC=BB=AC=EB=A0=89=EC=85=98=20Answers=20=EC=83=9D=EC=84=B1=20?=
 =?UTF-8?q?=EB=B0=8F=20answers=20=EA=B4=80=EB=A0=A8=20=EA=B6=8C=ED=95=9C?=
 =?UTF-8?q?=20=EC=9D=B4=EB=8F=99?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../java/nextstep/qna/domain/Answers.java     | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 src/main/java/nextstep/qna/domain/Answers.java

diff --git a/src/main/java/nextstep/qna/domain/Answers.java b/src/main/java/nextstep/qna/domain/Answers.java
new file mode 100644
index 0000000000..7a0c46fe43
--- /dev/null
+++ b/src/main/java/nextstep/qna/domain/Answers.java
@@ -0,0 +1,32 @@
+package nextstep.qna.domain;
+
+import nextstep.qna.CannotDeleteException;
+import nextstep.users.domain.NsUser;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class Answers {
+    private final List<Answer> values;
+
+    public Answers() {
+        this.values = new ArrayList<>();
+    }
+
+    public void add(Answer answer) {
+        values.add(answer);
+    }
+
+    public void validateOwnerships(NsUser loginUser) throws CannotDeleteException {
+        for (Answer answer : values) {
+            answer.validateOwnership(loginUser);
+        }
+    }
+
+    public List<DeleteHistory> deleteAnswers() {
+        return values.stream()
+                .map(Answer::delete)
+                .collect(Collectors.toList());
+    }
+}

From 14635ef1c2eec0875f260cca66f8ab920053b373 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 22:37:22 +0900
Subject: [PATCH 08/37] =?UTF-8?q?feat=20DeleteHistory=EC=97=90=EC=84=9C=20?=
 =?UTF-8?q?answer=EC=99=80=20question=EC=9D=84=20=EB=B0=9B=EC=95=84=20?=
 =?UTF-8?q?=EC=83=9D=EC=84=B1=ED=95=98=EB=8A=94=20=EA=B8=B0=EB=8A=A5=20?=
 =?UTF-8?q?=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/nextstep/qna/domain/DeleteHistory.java | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/main/java/nextstep/qna/domain/DeleteHistory.java b/src/main/java/nextstep/qna/domain/DeleteHistory.java
index 43c37e5e5c..c6169d327f 100644
--- a/src/main/java/nextstep/qna/domain/DeleteHistory.java
+++ b/src/main/java/nextstep/qna/domain/DeleteHistory.java
@@ -19,6 +19,14 @@ public class DeleteHistory {
     public DeleteHistory() {
     }
 
+    public static DeleteHistory ofQuestion(Question q) {
+        return new DeleteHistory(ContentType.QUESTION, q.getId(), q.getWriter(), LocalDateTime.now());
+    }
+
+    public static DeleteHistory ofAnswer(Answer a) {
+        return new DeleteHistory(ContentType.ANSWER, a.getId(), a.getWriter(), LocalDateTime.now());
+    }
+
     public DeleteHistory(ContentType contentType, Long contentId, NsUser deletedBy, LocalDateTime createdDate) {
         this.contentType = contentType;
         this.contentId = contentId;

From 163d9030acdd3eb4b6ac10098625d5e5f2a68976 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 22:38:10 +0900
Subject: [PATCH 09/37] =?UTF-8?q?test=20=EC=A7=88=EB=AC=B8=20=EC=82=AD?=
 =?UTF-8?q?=EC=A0=9C=EC=9D=98=20=EB=AA=A8=EB=93=A0=20=EA=B3=BC=EC=A0=95?=
 =?UTF-8?q?=EC=9D=84=20delete=20=EB=A9=94=EC=84=9C=EB=93=9C=EC=97=90=20?=
 =?UTF-8?q?=EC=B6=94=EA=B0=80=ED=95=98=EA=B8=B0=20=EC=9C=84=ED=95=B4=20?=
 =?UTF-8?q?=ED=85=8C=EC=8A=A4=ED=8A=B8=20=EC=88=98=EC=A0=95?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/test/java/nextstep/qna/domain/QuestionTest.java | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/test/java/nextstep/qna/domain/QuestionTest.java b/src/test/java/nextstep/qna/domain/QuestionTest.java
index 15f57d1ceb..bd0e93c220 100644
--- a/src/test/java/nextstep/qna/domain/QuestionTest.java
+++ b/src/test/java/nextstep/qna/domain/QuestionTest.java
@@ -11,12 +11,12 @@ public class QuestionTest {
 
     @Test
     void 질문_작성자가_자신일_경우_예외가_발생하지_않는다() throws CannotDeleteException {
-        Q1.validateOwnership(NsUserTest.JAVAJIGI);
+        Q1.delete(NsUserTest.JAVAJIGI);
     }
 
     @Test
     void 질문_작성자가_타인일_경우_예외가_발생한다() {
-        Assertions.assertThatThrownBy(() -> Q1.validateOwnership(NsUserTest.SANJIGI))
+        Assertions.assertThatThrownBy(() -> Q1.delete(NsUserTest.SANJIGI))
                 .isInstanceOf(CannotDeleteException.class)
                 .hasMessageContaining("질문을 삭제할 권한이 없습니다.");
     }

From 622012cb5fc8dec52fbd71ea237b6501b652775d Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 9 Apr 2025 22:39:02 +0900
Subject: [PATCH 10/37] =?UTF-8?q?refactor=20=EC=A7=88=EB=AC=B8=20=EB=B0=8F?=
 =?UTF-8?q?=20=EB=8B=B5=EB=B3=80=20=EC=82=AD=EC=A0=9C=20=EA=B3=BC=EC=A0=95?=
 =?UTF-8?q?=20=EC=A7=88=EB=AC=B8=20=ED=81=B4=EB=9E=98=EC=8A=A4=EC=97=90?=
 =?UTF-8?q?=EC=84=9C=20=EC=A7=84=ED=96=89=ED=95=98=EB=8F=84=EB=A1=9D=20?=
 =?UTF-8?q?=EB=A6=AC=ED=8C=A9=ED=86=A0=EB=A7=81?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../java/nextstep/qna/domain/Question.java    | 25 ++++++++++++++++---
 .../java/nextstep/qna/service/QnAService.java | 18 +------------
 2 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/src/main/java/nextstep/qna/domain/Question.java b/src/main/java/nextstep/qna/domain/Question.java
index 9c0b5bcb8a..eca6f685f6 100644
--- a/src/main/java/nextstep/qna/domain/Question.java
+++ b/src/main/java/nextstep/qna/domain/Question.java
@@ -16,7 +16,7 @@ public class Question {
 
     private NsUser writer;
 
-    private List<Answer> answers = new ArrayList<>();
+    private Answers answers;
 
     private boolean deleted = false;
 
@@ -36,14 +36,32 @@ public Question(Long id, NsUser writer, String title, String contents) {
         this.writer = writer;
         this.title = title;
         this.contents = contents;
+        this.answers = new Answers();
     }
 
-    public void validateOwnership(NsUser loginUser) throws CannotDeleteException {
+    public List<DeleteHistory> delete(NsUser loginUser) throws CannotDeleteException {
+        validateOwnership(loginUser);
+        validateAnswersOwnership(loginUser);
+
+        this.deleted = true;
+
+        List<DeleteHistory> deleteHistories = new ArrayList<>();
+        deleteHistories.add(DeleteHistory.ofQuestion(this));
+        deleteHistories.addAll(answers.deleteAnswers());
+
+        return deleteHistories;
+    }
+
+    private void validateOwnership(NsUser loginUser) throws CannotDeleteException {
         if (!isOwner(loginUser)) {
             throw new CannotDeleteException("질문을 삭제할 권한이 없습니다.");
         }
     }
 
+    private void validateAnswersOwnership(NsUser loginUser) throws CannotDeleteException {
+        answers.validateOwnerships(loginUser);
+    }
+
     public Long getId() {
         return id;
     }
@@ -80,7 +98,6 @@ private boolean isOwner(NsUser loginUser) {
     }
 
     public Question setDeleted(boolean deleted) {
-        this.deleted = deleted;
         return this;
     }
 
@@ -88,7 +105,7 @@ public boolean isDeleted() {
         return deleted;
     }
 
-    public List<Answer> getAnswers() {
+    public Answers getAnswers() {
         return answers;
     }
 
diff --git a/src/main/java/nextstep/qna/service/QnAService.java b/src/main/java/nextstep/qna/service/QnAService.java
index 4bf1cb6e63..bde6a7e4f1 100644
--- a/src/main/java/nextstep/qna/service/QnAService.java
+++ b/src/main/java/nextstep/qna/service/QnAService.java
@@ -26,22 +26,6 @@ public class QnAService {
     @Transactional
     public void deleteQuestion(NsUser loginUser, long questionId) throws CannotDeleteException {
         Question question = questionRepository.findById(questionId).orElseThrow(NotFoundException::new);
-        question.validateOwnership(loginUser);
-
-        List<Answer> answers = question.getAnswers();
-        for (Answer answer : answers) {
-            if (!answer.isOwner(loginUser)) {
-                throw new CannotDeleteException("다른 사람이 쓴 답변이 있어 삭제할 수 없습니다.");
-            }
-        }
-
-        List<DeleteHistory> deleteHistories = new ArrayList<>();
-        question.setDeleted(true);
-        deleteHistories.add(new DeleteHistory(ContentType.QUESTION, questionId, question.getWriter(), LocalDateTime.now()));
-        for (Answer answer : answers) {
-            answer.setDeleted(true);
-            deleteHistories.add(new DeleteHistory(ContentType.ANSWER, answer.getId(), answer.getWriter(), LocalDateTime.now()));
-        }
-        deleteHistoryService.saveAll(deleteHistories);
+        deleteHistoryService.saveAll(question.delete(loginUser));
     }
 }

From 6d53e299cc00e6bc82074f4db5f4cda635a26b0e Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Sun, 13 Apr 2025 21:18:12 +0900
Subject: [PATCH 11/37] =?UTF-8?q?fix=20=ED=94=BC=EB=93=9C=EB=B0=B1=20?=
 =?UTF-8?q?=EB=B0=98=EC=98=81?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/nextstep/qna/domain/Answer.java    |  7 ++++---
 src/main/java/nextstep/qna/domain/Answers.java   | 16 ++++++++--------
 .../java/nextstep/qna/domain/DeleteHistory.java  |  4 ++--
 src/main/java/nextstep/qna/domain/Question.java  | 10 ++--------
 4 files changed, 16 insertions(+), 21 deletions(-)

diff --git a/src/main/java/nextstep/qna/domain/Answer.java b/src/main/java/nextstep/qna/domain/Answer.java
index 624e4d5519..684245e349 100644
--- a/src/main/java/nextstep/qna/domain/Answer.java
+++ b/src/main/java/nextstep/qna/domain/Answer.java
@@ -46,13 +46,14 @@ public Answer(Long id, NsUser writer, Question question, String contents) {
 
     public void validateOwnership(NsUser loginUser) throws CannotDeleteException {
         if (!isOwner(loginUser)) {
-            throw new CannotDeleteException("다른 사람이 쓴 답변이 있어 삭제할 수 없습니다.");
+            throw new CannotDeleteException("답변을 삭제할 권한이 없습니다.");
         }
     }
 
-    public DeleteHistory delete() {
+    public DeleteHistory delete(NsUser loginUser) throws CannotDeleteException {
+        validateOwnership(loginUser);
         deleted = true;
-        return DeleteHistory.ofAnswer(this);
+        return DeleteHistory.deleteOfAnswer(this);
     }
 
     public Long getId() {
diff --git a/src/main/java/nextstep/qna/domain/Answers.java b/src/main/java/nextstep/qna/domain/Answers.java
index 7a0c46fe43..f03e1a5d6c 100644
--- a/src/main/java/nextstep/qna/domain/Answers.java
+++ b/src/main/java/nextstep/qna/domain/Answers.java
@@ -18,15 +18,15 @@ public void add(Answer answer) {
         values.add(answer);
     }
 
-    public void validateOwnerships(NsUser loginUser) throws CannotDeleteException {
-        for (Answer answer : values) {
-            answer.validateOwnership(loginUser);
-        }
-    }
-
-    public List<DeleteHistory> deleteAnswers() {
+    public List<DeleteHistory> deleteAnswers(NsUser loginUser) {
         return values.stream()
-                .map(Answer::delete)
+                .map(value -> {
+                    try {
+                        return value.delete(loginUser);
+                    } catch (CannotDeleteException e) {
+                        throw new RuntimeException(e);
+                    }
+                })
                 .collect(Collectors.toList());
     }
 }
diff --git a/src/main/java/nextstep/qna/domain/DeleteHistory.java b/src/main/java/nextstep/qna/domain/DeleteHistory.java
index c6169d327f..93751d76e0 100644
--- a/src/main/java/nextstep/qna/domain/DeleteHistory.java
+++ b/src/main/java/nextstep/qna/domain/DeleteHistory.java
@@ -19,11 +19,11 @@ public class DeleteHistory {
     public DeleteHistory() {
     }
 
-    public static DeleteHistory ofQuestion(Question q) {
+    public static DeleteHistory deleteOfQuestion(Question q) {
         return new DeleteHistory(ContentType.QUESTION, q.getId(), q.getWriter(), LocalDateTime.now());
     }
 
-    public static DeleteHistory ofAnswer(Answer a) {
+    public static DeleteHistory deleteOfAnswer(Answer a) {
         return new DeleteHistory(ContentType.ANSWER, a.getId(), a.getWriter(), LocalDateTime.now());
     }
 
diff --git a/src/main/java/nextstep/qna/domain/Question.java b/src/main/java/nextstep/qna/domain/Question.java
index eca6f685f6..291eae6c81 100644
--- a/src/main/java/nextstep/qna/domain/Question.java
+++ b/src/main/java/nextstep/qna/domain/Question.java
@@ -41,13 +41,11 @@ public Question(Long id, NsUser writer, String title, String contents) {
 
     public List<DeleteHistory> delete(NsUser loginUser) throws CannotDeleteException {
         validateOwnership(loginUser);
-        validateAnswersOwnership(loginUser);
-
         this.deleted = true;
 
         List<DeleteHistory> deleteHistories = new ArrayList<>();
-        deleteHistories.add(DeleteHistory.ofQuestion(this));
-        deleteHistories.addAll(answers.deleteAnswers());
+        deleteHistories.add(DeleteHistory.deleteOfQuestion(this));
+        deleteHistories.addAll(answers.deleteAnswers(loginUser));
 
         return deleteHistories;
     }
@@ -58,10 +56,6 @@ private void validateOwnership(NsUser loginUser) throws CannotDeleteException {
         }
     }
 
-    private void validateAnswersOwnership(NsUser loginUser) throws CannotDeleteException {
-        answers.validateOwnerships(loginUser);
-    }
-
     public Long getId() {
         return id;
     }

From aaeb5021a76b3fb0b5b8e6203af7da74c355a3e9 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Mon, 14 Apr 2025 20:51:23 +0900
Subject: [PATCH 12/37] =?UTF-8?q?fix=20=ED=94=BC=EB=93=9C=EB=B0=B1=20?=
 =?UTF-8?q?=EB=B0=98=EC=98=81?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/nextstep/qna/domain/Answer.java        | 2 +-
 src/main/java/nextstep/qna/domain/DeleteHistory.java | 8 ++++----
 src/main/java/nextstep/qna/domain/Question.java      | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/main/java/nextstep/qna/domain/Answer.java b/src/main/java/nextstep/qna/domain/Answer.java
index 684245e349..13f1605f06 100644
--- a/src/main/java/nextstep/qna/domain/Answer.java
+++ b/src/main/java/nextstep/qna/domain/Answer.java
@@ -53,7 +53,7 @@ public void validateOwnership(NsUser loginUser) throws CannotDeleteException {
     public DeleteHistory delete(NsUser loginUser) throws CannotDeleteException {
         validateOwnership(loginUser);
         deleted = true;
-        return DeleteHistory.deleteOfAnswer(this);
+        return DeleteHistory.ofAnswer(this);
     }
 
     public Long getId() {
diff --git a/src/main/java/nextstep/qna/domain/DeleteHistory.java b/src/main/java/nextstep/qna/domain/DeleteHistory.java
index 93751d76e0..4f2abf4737 100644
--- a/src/main/java/nextstep/qna/domain/DeleteHistory.java
+++ b/src/main/java/nextstep/qna/domain/DeleteHistory.java
@@ -19,12 +19,12 @@ public class DeleteHistory {
     public DeleteHistory() {
     }
 
-    public static DeleteHistory deleteOfQuestion(Question q) {
-        return new DeleteHistory(ContentType.QUESTION, q.getId(), q.getWriter(), LocalDateTime.now());
+    public static DeleteHistory ofQuestion(Question question) {
+        return new DeleteHistory(ContentType.QUESTION, question.getId(), question.getWriter(), LocalDateTime.now());
     }
 
-    public static DeleteHistory deleteOfAnswer(Answer a) {
-        return new DeleteHistory(ContentType.ANSWER, a.getId(), a.getWriter(), LocalDateTime.now());
+    public static DeleteHistory ofAnswer(Answer answer) {
+        return new DeleteHistory(ContentType.ANSWER, answer.getId(), answer.getWriter(), LocalDateTime.now());
     }
 
     public DeleteHistory(ContentType contentType, Long contentId, NsUser deletedBy, LocalDateTime createdDate) {
diff --git a/src/main/java/nextstep/qna/domain/Question.java b/src/main/java/nextstep/qna/domain/Question.java
index 291eae6c81..ecdd2544a2 100644
--- a/src/main/java/nextstep/qna/domain/Question.java
+++ b/src/main/java/nextstep/qna/domain/Question.java
@@ -44,7 +44,7 @@ public List<DeleteHistory> delete(NsUser loginUser) throws CannotDeleteException
         this.deleted = true;
 
         List<DeleteHistory> deleteHistories = new ArrayList<>();
-        deleteHistories.add(DeleteHistory.deleteOfQuestion(this));
+        deleteHistories.add(DeleteHistory.ofQuestion(this));
         deleteHistories.addAll(answers.deleteAnswers(loginUser));
 
         return deleteHistories;

From 8a8a1952387a39d440d2165faca63c8e8d044d6f Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Mon, 14 Apr 2025 20:52:12 +0900
Subject: [PATCH 13/37] =?UTF-8?q?test=20=EC=98=88=EC=99=B8=20=EC=B2=98?=
 =?UTF-8?q?=EB=A6=AC=20=EB=A9=94=EC=8B=9C=EC=A7=80=EA=B0=80=20=EB=B3=80?=
 =?UTF-8?q?=EA=B2=BD=EB=90=A8=EC=97=90=20=EB=94=B0=EB=A5=B8=20=ED=85=8C?=
 =?UTF-8?q?=EC=8A=A4=ED=8A=B8=20=EB=B3=80=EA=B2=BD?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/test/java/nextstep/qna/domain/AnswerTest.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/test/java/nextstep/qna/domain/AnswerTest.java b/src/test/java/nextstep/qna/domain/AnswerTest.java
index 6558877335..d5d119fd73 100644
--- a/src/test/java/nextstep/qna/domain/AnswerTest.java
+++ b/src/test/java/nextstep/qna/domain/AnswerTest.java
@@ -18,6 +18,6 @@ public class AnswerTest {
     void 답변_작성자가_타인일_경우_예외가_발생한다() {
         Assertions.assertThatThrownBy(() -> A1.validateOwnership(NsUserTest.SANJIGI))
                 .isInstanceOf(CannotDeleteException.class)
-                .hasMessageContaining("다른 사람이 쓴 답변이 있어 삭제할 수 없습니다.");
+                .hasMessageContaining("답변을 삭제할 권한이 없습니다.");
     }
 }

From c23a134b1bb14faa76fea254f28e249e1c25b782 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Mon, 14 Apr 2025 23:32:21 +0900
Subject: [PATCH 14/37] =?UTF-8?q?docs=20step2=20=EA=B8=B0=EB=8A=A5=20?=
 =?UTF-8?q?=EB=AA=A9=EB=A1=9D=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 docs/step2.md

diff --git a/docs/step2.md b/docs/step2.md
new file mode 100644
index 0000000000..9bbe986de2
--- /dev/null
+++ b/docs/step2.md
@@ -0,0 +1,31 @@
+## 기능 요구사항
+- 과정(Course)은 기수 단위로 운영하며, 여러 개의 강의(Session)를 가질 수 있다.
+- 강의는 시작일과 종료일을 가진다.
+- 강의는 강의 커버 이미지 정보를 가진다.
+- 이미지 크기는 1MB 이하여야 한다.
+- 이미지 타입은 gif, jpg(jpeg 포함),, png, svg만 허용한다.
+- 이미지의 width는 300픽셀, height는 200픽셀 이상이어야 하며, width와 height의 비율은 3:2여야 한다.
+- 강의는 무료 강의와 유료 강의로 나뉜다.
+- 무료 강의는 최대 수강 인원 제한이 없다.
+- 유료 강의는 강의 최대 수강 인원을 초과할 수 없다.
+- 유료 강의는 수강생이 결제한 금액과 수강료가 일치할 때 수강 신청이 가능하다.
+- 강의 상태는 준비중, 모집중, 종료 3가지 상태를 가진다.
+- 강의 수강신청은 강의 상태가 모집중일 때만 가능하다.
+- 유료 강의의 경우 결제는 이미 완료한 것으로 가정하고 이후 과정을 구현한다.
+- 결제를 완료한 결제 정보는 payments 모듈을 통해 관리되며, 결제 정보는 Payment 객체에 담겨 반한된다.
+
+## 기능 목록
+- [ ] 강의의 종료일보다 시작일이 더 이후인지 확인한다.
+- [ ] 강의 커버 이미지의 크기가 1MB 이하인지 확인한다.
+- [ ] 이미지 타입이 gif, jpg, png, svg인지 확인한다.
+- [ ] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
+- [ ] 이미지의 width와 height 비율이 3:2인지 확인한다.
+- [ ] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
+- [ ] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
+- [ ] 수강 신청을 한다.
+- [ ] 강의 상태가 모집중인지 확인한다.
+- [ ] 결제 정보를 조회한다.
+- [ ] 강의를 생성한다.
+- [ ] 강의 상태를 변경한다.
+- [ ] 과정을 생성한다.
+- [ ] 과정에 강의를 추가한다.
\ No newline at end of file

From e3f5f4d1d79e1db41038f1db8c46d09e39e46b8a Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 20:20:06 +0900
Subject: [PATCH 15/37] =?UTF-8?q?test=20SessionPeriod=20=ED=85=8C=EC=8A=A4?=
 =?UTF-8?q?=ED=8A=B8=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../sessions/domain/SessionPeriodTest.java    | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 src/test/java/nextstep/sessions/domain/SessionPeriodTest.java

diff --git a/src/test/java/nextstep/sessions/domain/SessionPeriodTest.java b/src/test/java/nextstep/sessions/domain/SessionPeriodTest.java
new file mode 100644
index 0000000000..e5c0c5b03f
--- /dev/null
+++ b/src/test/java/nextstep/sessions/domain/SessionPeriodTest.java
@@ -0,0 +1,34 @@
+package nextstep.sessions.domain;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.Date;
+
+public class SessionPeriodTest {
+    private Date earlier;
+    private Date later;
+
+    @BeforeEach
+    void setUp() {
+        this.earlier = new Date(2025, 1, 1);
+        this.later = new Date(2025, 3, 1);
+    }
+
+    @Test
+    @DisplayName("시작일이 종료일보다 이전이면 기간을 정상 생성한다.")
+    void 기간_정상_생성() {
+        SessionPeriod sessionPeriod = new SessionPeriod(earlier, later);
+    }
+
+    @Test
+    @DisplayName("시작일이 종료일보다 늦으면 IllegalArgumentException을 던진다.")
+    void 시작일이_종료일보다_늦으면_예외발생() {
+        Assertions.assertThatIllegalArgumentException().isThrownBy(()
+                -> new SessionPeriod(later, earlier))
+                .withMessage("시작일은 종료일보다 이전이어야 합니다.");
+
+    }
+}

From ac80d4f7318391d2ba947b5a0b43cc61f67e635c Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 20:24:17 +0900
Subject: [PATCH 16/37] =?UTF-8?q?feat=20=EA=B0=95=EC=9D=98=20=EA=B8=B0?=
 =?UTF-8?q?=EA=B0=84=20=ED=81=B4=EB=9E=98=EC=8A=A4=20=EC=83=9D=EC=84=B1=20?=
 =?UTF-8?q?=EB=B0=8F=20=EA=B0=95=EC=9D=98=20=EC=8B=9C=EC=9E=91=EC=9D=BC,?=
 =?UTF-8?q?=20=EC=A2=85=EB=A3=8C=EC=9D=BC=20=EA=B2=80=EC=A6=9D=20=EA=B8=B0?=
 =?UTF-8?q?=EB=8A=A5=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                 |  2 +-
 .../sessions/domain/SessionPeriod.java        | 20 +++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/nextstep/sessions/domain/SessionPeriod.java

diff --git a/docs/step2.md b/docs/step2.md
index 9bbe986de2..7a96c0a4a2 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -15,7 +15,7 @@
 - 결제를 완료한 결제 정보는 payments 모듈을 통해 관리되며, 결제 정보는 Payment 객체에 담겨 반한된다.
 
 ## 기능 목록
-- [ ] 강의의 종료일보다 시작일이 더 이후인지 확인한다.
+- [x] 강의의 종료일보다 시작일이 더 이후인지 확인한다.
 - [ ] 강의 커버 이미지의 크기가 1MB 이하인지 확인한다.
 - [ ] 이미지 타입이 gif, jpg, png, svg인지 확인한다.
 - [ ] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
diff --git a/src/main/java/nextstep/sessions/domain/SessionPeriod.java b/src/main/java/nextstep/sessions/domain/SessionPeriod.java
new file mode 100644
index 0000000000..d9aae583ab
--- /dev/null
+++ b/src/main/java/nextstep/sessions/domain/SessionPeriod.java
@@ -0,0 +1,20 @@
+package nextstep.sessions.domain;
+
+import java.util.Date;
+
+public class SessionPeriod {
+    private Date startDate;
+    private Date endDate;
+
+    public SessionPeriod(Date startDate, Date endDate) {
+        validate(startDate, endDate);
+        this.startDate = startDate;
+        this.endDate = endDate;
+    }
+
+    private void validate(Date startDate, Date endDate) {
+        if (startDate.after(endDate)) {
+            throw new IllegalArgumentException("시작일은 종료일보다 이전이어야 합니다.");
+        }
+    }
+}

From 8059451cc5f098c7087485155294f47e6f8bd8e4 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 20:45:10 +0900
Subject: [PATCH 17/37] =?UTF-8?q?test=20=EC=9D=B4=EB=AF=B8=EC=A7=80=20?=
 =?UTF-8?q?=ED=81=AC=EA=B8=B0=20=ED=85=8C=EC=8A=A4=ED=8A=B8=20=EC=B6=94?=
 =?UTF-8?q?=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../nextstep/sessions/domain/ImageTest.java   | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 src/test/java/nextstep/sessions/domain/ImageTest.java

diff --git a/src/test/java/nextstep/sessions/domain/ImageTest.java b/src/test/java/nextstep/sessions/domain/ImageTest.java
new file mode 100644
index 0000000000..bbd7180873
--- /dev/null
+++ b/src/test/java/nextstep/sessions/domain/ImageTest.java
@@ -0,0 +1,20 @@
+package nextstep.sessions.domain;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+public class ImageTest {
+    @Test
+    @DisplayName("이미지 최대 크기를 초과할 시 IllegalArgumentException을 던진다.")
+    void 이미지_크기_초과() {
+        Assertions.assertThatIllegalArgumentException().isThrownBy(() ->
+                new Image(2_000_000L, "이미지", ImageType.JPEG, 300F, 200F));
+    }
+
+    @Test
+    @DisplayName("이미지 최대 크기를 초과하지 않으면 이미지가 잘 생성된다.")
+    void 이미지_크기_적정() {
+        Image image = new Image(1_000_000L, "이미지", ImageType.JPEG, 300F, 200F);
+    }
+}

From ea804075e3641287042de32ccf8672366844dc29 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 20:47:08 +0900
Subject: [PATCH 18/37] =?UTF-8?q?feat=20=EC=9D=B4=EB=AF=B8=EC=A7=80=20?=
 =?UTF-8?q?=ED=81=B4=EB=9E=98=EC=8A=A4=20=EC=83=9D=EC=84=B1=20=EB=B0=8F=20?=
 =?UTF-8?q?=EC=9D=B4=EB=AF=B8=EC=A7=80=20=ED=81=AC=EA=B8=B0=20=EA=B2=80?=
 =?UTF-8?q?=EC=A6=9D=20=EA=B8=B0=EB=8A=A5=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                 |  2 +-
 .../java/nextstep/sessions/domain/Image.java  | 38 +++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/nextstep/sessions/domain/Image.java

diff --git a/docs/step2.md b/docs/step2.md
index 7a96c0a4a2..2d736e0364 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -16,7 +16,7 @@
 
 ## 기능 목록
 - [x] 강의의 종료일보다 시작일이 더 이후인지 확인한다.
-- [ ] 강의 커버 이미지의 크기가 1MB 이하인지 확인한다.
+- [x] 강의 커버 이미지의 크기가 1MB 이하인지 확인한다.
 - [ ] 이미지 타입이 gif, jpg, png, svg인지 확인한다.
 - [ ] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
 - [ ] 이미지의 width와 height 비율이 3:2인지 확인한다.
diff --git a/src/main/java/nextstep/sessions/domain/Image.java b/src/main/java/nextstep/sessions/domain/Image.java
new file mode 100644
index 0000000000..e41df056bf
--- /dev/null
+++ b/src/main/java/nextstep/sessions/domain/Image.java
@@ -0,0 +1,38 @@
+package nextstep.sessions.domain;
+
+public class Image {
+    private static final Long MAX_SIZE_BYTES = 1_048_576L;
+    private static final Float MIN_SIZE_WIDTH = 300F;
+    private static final Float MIN_SIZE_HEIGHT = 200F;
+
+    private Long id;
+    private Long sizeInBytes;
+    private String title;
+    private ImageType type;
+    private Float width;
+    private Float height;
+
+    public Image(Long sizeInBytes, String title, ImageType type, Float width, Float height) {
+        this(sizeInBytes, 0L, title, type, width, height);
+    }
+
+    public Image(Long sizeInBytes, Long id, String title, ImageType type, Float width, Float height) {
+        validate(sizeInBytes, title, type, width, height);
+        this.sizeInBytes = sizeInBytes;
+        this.id = id;
+        this.title = title;
+        this.type = type;
+        this.width = width;
+        this.height = height;
+    }
+
+    private void validate(Long sizeInBytes, String title, ImageType type, Float width, Float height) {
+        validateSize(sizeInBytes);
+    }
+
+    private void validateSize(Long sizeInBytes) {
+        if (sizeInBytes > MAX_SIZE_BYTES) {
+            throw new IllegalArgumentException("이미지 크기는 최대 1MB 이하여야 합니다.");
+        }
+    }
+}

From 1e6b44f3d13efd6da87279a851ac739913b223b2 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 20:53:46 +0900
Subject: [PATCH 19/37] =?UTF-8?q?test=20=EC=9D=B4=EB=AF=B8=EC=A7=80=20?=
 =?UTF-8?q?=ED=83=80=EC=9E=85=20=EA=B2=80=EC=82=AC=20=ED=85=8C=EC=8A=A4?=
 =?UTF-8?q?=ED=8A=B8=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../sessions/domain/ImageTypeTest.java        | 26 +++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 src/test/java/nextstep/sessions/domain/ImageTypeTest.java

diff --git a/src/test/java/nextstep/sessions/domain/ImageTypeTest.java b/src/test/java/nextstep/sessions/domain/ImageTypeTest.java
new file mode 100644
index 0000000000..6152054633
--- /dev/null
+++ b/src/test/java/nextstep/sessions/domain/ImageTypeTest.java
@@ -0,0 +1,26 @@
+package nextstep.sessions.domain;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.*;
+
+public class ImageTypeTest {
+
+    @Test
+    @DisplayName("지원하는 이미지 타입은 enum으로 정상 변환된다.")
+    void 지원하는_이미지_타입_변환_성공() {
+        assertThat(ImageType.from("gif")).isEqualTo(ImageType.GIF);
+        assertThat(ImageType.from("jpg")).isEqualTo(ImageType.JPG);
+        assertThat(ImageType.from("jpeg")).isEqualTo(ImageType.JPEG);
+        assertThat(ImageType.from("png")).isEqualTo(ImageType.PNG);
+        assertThat(ImageType.from("svg")).isEqualTo(ImageType.SVG);
+    }
+
+    @Test
+    @DisplayName("지원하지 않는 이미지 타입은 IllegalArgumentException을 던진다.")
+    void 지원하지_않는_이미지_타입_예외() {
+        assertThatIllegalArgumentException().isThrownBy(() -> ImageType.from("java"))
+                .withMessage("지원하지 않는 이미지 타입입니다.");
+    }
+}

From 1e733eb530097fa83c8241317caea5a423d58997 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 20:54:42 +0900
Subject: [PATCH 20/37] =?UTF-8?q?feat=20=EC=9D=B4=EB=AF=B8=EC=A7=80=20?=
 =?UTF-8?q?=ED=83=80=EC=9E=85=20=EC=83=9D=EC=84=B1=20=EB=B0=8F=20=EA=B2=80?=
 =?UTF-8?q?=EC=A6=9D=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                       |  2 +-
 .../java/nextstep/sessions/domain/ImageType.java    | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/nextstep/sessions/domain/ImageType.java

diff --git a/docs/step2.md b/docs/step2.md
index 2d736e0364..25c663449f 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -17,7 +17,7 @@
 ## 기능 목록
 - [x] 강의의 종료일보다 시작일이 더 이후인지 확인한다.
 - [x] 강의 커버 이미지의 크기가 1MB 이하인지 확인한다.
-- [ ] 이미지 타입이 gif, jpg, png, svg인지 확인한다.
+- [x] 이미지 타입이 gif, jpg, png, svg인지 확인한다.
 - [ ] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
 - [ ] 이미지의 width와 height 비율이 3:2인지 확인한다.
 - [ ] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
diff --git a/src/main/java/nextstep/sessions/domain/ImageType.java b/src/main/java/nextstep/sessions/domain/ImageType.java
new file mode 100644
index 0000000000..4f642050f5
--- /dev/null
+++ b/src/main/java/nextstep/sessions/domain/ImageType.java
@@ -0,0 +1,13 @@
+package nextstep.sessions.domain;
+
+public enum ImageType {
+    GIF, JPG, JPEG, PNG, SVG;
+
+    public static ImageType from(String type) {
+        try {
+            return ImageType.valueOf(type.toUpperCase());
+        } catch (IllegalArgumentException e) {
+            throw new IllegalArgumentException("지원하지 않는 이미지 타입입니다.");
+        }
+    }
+}

From dd156997b679d2a53b54a80283a12f3e2b69cbfc Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 21:06:10 +0900
Subject: [PATCH 21/37] =?UTF-8?q?test=20=EC=9D=B4=EB=AF=B8=EC=A7=80=20?=
 =?UTF-8?q?=EA=B0=80=EB=A1=9C,=20=EC=84=B8=EB=A1=9C=20=EA=B8=B8=EC=9D=B4?=
 =?UTF-8?q?=20=ED=85=8C=EC=8A=A4=ED=8A=B8=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../nextstep/sessions/domain/ImageTest.java   | 30 ++++++++++++++++---
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/src/test/java/nextstep/sessions/domain/ImageTest.java b/src/test/java/nextstep/sessions/domain/ImageTest.java
index bbd7180873..da1fd31a14 100644
--- a/src/test/java/nextstep/sessions/domain/ImageTest.java
+++ b/src/test/java/nextstep/sessions/domain/ImageTest.java
@@ -1,20 +1,42 @@
 package nextstep.sessions.domain;
 
-import org.assertj.core.api.Assertions;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
+import static org.assertj.core.api.Assertions.*;
+
 public class ImageTest {
     @Test
     @DisplayName("이미지 최대 크기를 초과할 시 IllegalArgumentException을 던진다.")
     void 이미지_크기_초과() {
-        Assertions.assertThatIllegalArgumentException().isThrownBy(() ->
-                new Image(2_000_000L, "이미지", ImageType.JPEG, 300F, 200F));
+        assertThatIllegalArgumentException().isThrownBy(() ->
+                new Image(2_000_000L, "이미지", ImageType.JPEG, 300F, 200F))
+                .withMessage("이미지 크기는 최대 1MB 이하여야 합니다.");
     }
 
     @Test
     @DisplayName("이미지 최대 크기를 초과하지 않으면 이미지가 잘 생성된다.")
     void 이미지_크기_적정() {
-        Image image = new Image(1_000_000L, "이미지", ImageType.JPEG, 300F, 200F);
+        new Image(1_000_000L, "이미지", ImageType.JPEG, 300F, 200F);
+    }
+
+    @Test
+    @DisplayName("이미지 가로 길이가 300보다 작을 시 IllegalArgumentException을 던진다.")
+    void 이미지_최소_가로_크기_부적절() {
+        assertThatIllegalArgumentException().isThrownBy(() ->
+                new Image(1_000_000L, "이미지", ImageType.JPEG, 200F, 200F))
+                .withMessage("이미지 가로 길이는 최소 300픽셀 이상이어야 합니다.");
+    }
+
+    @Test
+    @DisplayName("이미지 가로 길이가 300이상이면 정상적으로 생성된다.")
+    void 이미지_최소_가로_크기_적절() {
+        new Image(1_000_000L, "이미지", ImageType.JPEG, 300F, 200F);
+    }
+
+    @Test
+    @DisplayName("이미지 세로 길이가 200이상이면 정상적으로 생성된다.")
+    void 이미지_최소_세로_크기_적절() {
+        new Image(1_000_000L, "이미지", ImageType.JPEG, 300F, 200F);
     }
 }

From 3a3850750d278e5e704466f84e37c748e4961f5d Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 21:06:53 +0900
Subject: [PATCH 22/37] =?UTF-8?q?feat=20=EC=9D=B4=EB=AF=B8=EC=A7=80=20?=
 =?UTF-8?q?=EA=B0=80=EB=A1=9C,=20=EC=84=B8=EB=A1=9C=20=EA=B8=B8=EC=9D=B4?=
 =?UTF-8?q?=20=EA=B2=80=EC=A6=9D=20=EA=B8=B0=EB=8A=A5=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                     |  2 +-
 src/main/java/nextstep/sessions/domain/Image.java | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/docs/step2.md b/docs/step2.md
index 25c663449f..9e074731ad 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -18,7 +18,7 @@
 - [x] 강의의 종료일보다 시작일이 더 이후인지 확인한다.
 - [x] 강의 커버 이미지의 크기가 1MB 이하인지 확인한다.
 - [x] 이미지 타입이 gif, jpg, png, svg인지 확인한다.
-- [ ] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
+- [x] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
 - [ ] 이미지의 width와 height 비율이 3:2인지 확인한다.
 - [ ] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
 - [ ] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
diff --git a/src/main/java/nextstep/sessions/domain/Image.java b/src/main/java/nextstep/sessions/domain/Image.java
index e41df056bf..cf48a0fcaf 100644
--- a/src/main/java/nextstep/sessions/domain/Image.java
+++ b/src/main/java/nextstep/sessions/domain/Image.java
@@ -28,6 +28,8 @@ public Image(Long sizeInBytes, Long id, String title, ImageType type, Float widt
 
     private void validate(Long sizeInBytes, String title, ImageType type, Float width, Float height) {
         validateSize(sizeInBytes);
+        validateWidth(width);
+        validateHeight(height);
     }
 
     private void validateSize(Long sizeInBytes) {
@@ -35,4 +37,16 @@ private void validateSize(Long sizeInBytes) {
             throw new IllegalArgumentException("이미지 크기는 최대 1MB 이하여야 합니다.");
         }
     }
+
+    private void validateWidth(Float width) {
+        if (width < MIN_SIZE_WIDTH) {
+            throw new IllegalArgumentException("이미지 가로 길이는 최소 300픽셀 이상이어야 합니다.");
+        }
+    }
+
+    private void validateHeight(Float height) {
+        if (height < MIN_SIZE_HEIGHT) {
+            throw new IllegalArgumentException("이미지 세로 길이는 최소 200픽셀 이상이어야 합니다.");
+        }
+    }
 }

From a14350fdb251abb6518c858fbdda1fa5d05bc8d9 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 21:12:59 +0900
Subject: [PATCH 23/37] =?UTF-8?q?test=20=EC=9D=B4=EB=AF=B8=EC=A7=80=20?=
 =?UTF-8?q?=EA=B0=80=EB=A1=9C=20=EC=84=B8=EB=A1=9C=20=EB=B9=84=EC=9C=A8=20?=
 =?UTF-8?q?=ED=85=8C=EC=8A=A4=ED=8A=B8=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../nextstep/sessions/domain/ImageTest.java   | 24 +++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/test/java/nextstep/sessions/domain/ImageTest.java b/src/test/java/nextstep/sessions/domain/ImageTest.java
index da1fd31a14..7f16df112e 100644
--- a/src/test/java/nextstep/sessions/domain/ImageTest.java
+++ b/src/test/java/nextstep/sessions/domain/ImageTest.java
@@ -10,7 +10,7 @@ public class ImageTest {
     @DisplayName("이미지 최대 크기를 초과할 시 IllegalArgumentException을 던진다.")
     void 이미지_크기_초과() {
         assertThatIllegalArgumentException().isThrownBy(() ->
-                new Image(2_000_000L, "이미지", ImageType.JPEG, 300F, 200F))
+                        new Image(2_000_000L, "이미지", ImageType.JPEG, 300F, 200F))
                 .withMessage("이미지 크기는 최대 1MB 이하여야 합니다.");
     }
 
@@ -24,7 +24,7 @@ public class ImageTest {
     @DisplayName("이미지 가로 길이가 300보다 작을 시 IllegalArgumentException을 던진다.")
     void 이미지_최소_가로_크기_부적절() {
         assertThatIllegalArgumentException().isThrownBy(() ->
-                new Image(1_000_000L, "이미지", ImageType.JPEG, 200F, 200F))
+                        new Image(1_000_000L, "이미지", ImageType.JPEG, 200F, 200F))
                 .withMessage("이미지 가로 길이는 최소 300픽셀 이상이어야 합니다.");
     }
 
@@ -39,4 +39,24 @@ public class ImageTest {
     void 이미지_최소_세로_크기_적절() {
         new Image(1_000_000L, "이미지", ImageType.JPEG, 300F, 200F);
     }
+
+    @Test
+    @DisplayName("이미지 가로 세로 비율이 3:2가 아니면 IllegalArgumentException을 던진다.")
+    void 이미지_가로_세로_비율_부적절() {
+        assertThatIllegalArgumentException().isThrownBy(() ->
+                        new Image(1_000_000L, "이미지", ImageType.JPEG, 400F, 200F))
+                .withMessage("이미지 비율은 3:2이어야 합니다.");
+    }
+
+    @Test
+    @DisplayName("이미지 가로 세로 비율이 3:2면 정상적으로 생성된다.")
+    void 이미지_가로_세로_비율_적절() {
+        new Image(1_000_000L, "이미지", ImageType.JPEG, 300F, 200F);
+    }
+
+    @Test
+    @DisplayName("이미지 가로 세로 비율이 약 3:2면 정상적으로 생성된다.")
+    void 이미지_가로_세로_비율_오차_범위_이내() {
+        new Image(1_000_000L, "이미지", ImageType.JPEG, 301F, 200F);
+    }
 }

From 5c177c358c049503c5e2dbc08721f21acbecee6c Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 21:13:26 +0900
Subject: [PATCH 24/37] =?UTF-8?q?feat=20=EC=9D=B4=EB=AF=B8=EC=A7=80?=
 =?UTF-8?q?=EC=9D=98=20=EA=B0=80=EB=A1=9C=20=EC=84=B8=EB=A1=9C=20=EB=B9=84?=
 =?UTF-8?q?=EC=9C=A8=EC=9D=B4=203:2=EC=9D=B8=EC=A7=80=20=ED=99=95=EC=9D=B8?=
 =?UTF-8?q?=ED=95=98=EB=8A=94=20=EA=B8=B0=EB=8A=A5=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                     | 2 +-
 src/main/java/nextstep/sessions/domain/Image.java | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/docs/step2.md b/docs/step2.md
index 9e074731ad..9eb15a49de 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -19,7 +19,7 @@
 - [x] 강의 커버 이미지의 크기가 1MB 이하인지 확인한다.
 - [x] 이미지 타입이 gif, jpg, png, svg인지 확인한다.
 - [x] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
-- [ ] 이미지의 width와 height 비율이 3:2인지 확인한다.
+- [x] 이미지의 width와 height 비율이 3:2인지 확인한다.
 - [ ] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
 - [ ] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
 - [ ] 수강 신청을 한다.
diff --git a/src/main/java/nextstep/sessions/domain/Image.java b/src/main/java/nextstep/sessions/domain/Image.java
index cf48a0fcaf..253a2ef401 100644
--- a/src/main/java/nextstep/sessions/domain/Image.java
+++ b/src/main/java/nextstep/sessions/domain/Image.java
@@ -30,6 +30,7 @@ private void validate(Long sizeInBytes, String title, ImageType type, Float widt
         validateSize(sizeInBytes);
         validateWidth(width);
         validateHeight(height);
+        validateAspectRatio(width, height);
     }
 
     private void validateSize(Long sizeInBytes) {
@@ -49,4 +50,11 @@ private void validateHeight(Float height) {
             throw new IllegalArgumentException("이미지 세로 길이는 최소 200픽셀 이상이어야 합니다.");
         }
     }
+
+    private void validateAspectRatio(float width, float height) {
+        float ratio = width / height;
+        if (Math.abs(ratio - 1.5) > 0.01) {
+            throw new IllegalArgumentException("이미지 비율은 3:2이어야 합니다.");
+        }
+    }
 }

From ec7e4779a30630cb6b4c39f2de4ab621041a77ed Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 21:39:52 +0900
Subject: [PATCH 25/37] =?UTF-8?q?test=20=EB=93=B1=EB=A1=9D=20=EC=9D=B8?=
 =?UTF-8?q?=EC=9B=90=20=ED=85=8C=EC=8A=A4=ED=8A=B8=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../domain/EnrollmentCapacityTest.java        | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 src/test/java/nextstep/sessions/domain/EnrollmentCapacityTest.java

diff --git a/src/test/java/nextstep/sessions/domain/EnrollmentCapacityTest.java b/src/test/java/nextstep/sessions/domain/EnrollmentCapacityTest.java
new file mode 100644
index 0000000000..c6bb6f8e16
--- /dev/null
+++ b/src/test/java/nextstep/sessions/domain/EnrollmentCapacityTest.java
@@ -0,0 +1,24 @@
+package nextstep.sessions.domain;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.*;
+
+class EnrollmentCapacityTest {
+    @Test
+    @DisplayName("정원이 가득 찬 경우 인원 증가 시 예외를 던진다.")
+    void 등록_인원_초과() {
+        EnrollmentCapacity enrollmentCapacity = new EnrollmentCapacity(1, 1);
+        assertThatThrownBy(enrollmentCapacity::increaseEnrollment)
+                .isInstanceOf(IllegalStateException.class)
+                .hasMessage("정원이 초과되었습니다.");
+    }
+
+    @Test
+    @DisplayName("정원이 가득 차지 않은 경우 등록 인원을 정상적으로 증가시킨다..")
+    void 등록_인원_증가() {
+        EnrollmentCapacity enrollmentCapacity = new EnrollmentCapacity(1, 0);
+        enrollmentCapacity.increaseEnrollment();
+    }
+}
\ No newline at end of file

From aab7ce1f1a1277f30b750480675adb0de150ed33 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 21:40:55 +0900
Subject: [PATCH 26/37] =?UTF-8?q?feat=20=EC=A0=95=EC=9B=90=EC=9D=B4=20?=
 =?UTF-8?q?=EC=B4=88=EA=B3=BC=ED=96=88=EB=8A=94=EC=A7=80=20=EA=B2=80?=
 =?UTF-8?q?=EC=82=AC=ED=95=98=EB=8A=94=20=EA=B8=B0=EB=8A=A5=20=EC=B6=94?=
 =?UTF-8?q?=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                 |  2 +-
 .../sessions/domain/EnrollmentCapacity.java   | 25 +++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/nextstep/sessions/domain/EnrollmentCapacity.java

diff --git a/docs/step2.md b/docs/step2.md
index 9eb15a49de..25a702ee32 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -20,7 +20,7 @@
 - [x] 이미지 타입이 gif, jpg, png, svg인지 확인한다.
 - [x] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
 - [x] 이미지의 width와 height 비율이 3:2인지 확인한다.
-- [ ] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
+- [x] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
 - [ ] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
 - [ ] 수강 신청을 한다.
 - [ ] 강의 상태가 모집중인지 확인한다.
diff --git a/src/main/java/nextstep/sessions/domain/EnrollmentCapacity.java b/src/main/java/nextstep/sessions/domain/EnrollmentCapacity.java
new file mode 100644
index 0000000000..e35b890db1
--- /dev/null
+++ b/src/main/java/nextstep/sessions/domain/EnrollmentCapacity.java
@@ -0,0 +1,25 @@
+package nextstep.sessions.domain;
+
+public class EnrollmentCapacity {
+    private int maxEnrollment;
+    private int currentEnrollment;
+
+    public EnrollmentCapacity(int maxEnrollment) {
+        this(maxEnrollment, 0);
+    }
+
+    public EnrollmentCapacity(int maxEnrollment, int currentEnrollment) {
+        this.maxEnrollment = maxEnrollment;
+        this.currentEnrollment = currentEnrollment;
+    }
+
+    public boolean isFull() {
+        return currentEnrollment >= maxEnrollment;
+    }
+
+    private void validate() {
+        if (isFull()) {
+            throw new IllegalStateException("정원이 초과되었습니다.");
+        }
+    }
+}

From 02cb05aac919300f714eec3d591d928524ab36b0 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 21:41:24 +0900
Subject: [PATCH 27/37] =?UTF-8?q?docs=20=EC=88=98=EA=B0=95=20=EC=9D=B8?=
 =?UTF-8?q?=EC=9B=90=20=EC=A6=9D=EA=B0=80=20=EA=B8=B0=EB=8A=A5=20=EC=B6=94?=
 =?UTF-8?q?=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docs/step2.md b/docs/step2.md
index 25a702ee32..40d829a042 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -21,6 +21,7 @@
 - [x] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
 - [x] 이미지의 width와 height 비율이 3:2인지 확인한다.
 - [x] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
+- [ ] 현재 수강 인원을 증가시킨다.
 - [ ] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
 - [ ] 수강 신청을 한다.
 - [ ] 강의 상태가 모집중인지 확인한다.

From 9265ddb7ed8a54a21674eb91a51b0e97549e764c Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Tue, 15 Apr 2025 21:41:59 +0900
Subject: [PATCH 28/37] =?UTF-8?q?feat=20=ED=98=84=EC=9E=AC=20=EC=88=98?=
 =?UTF-8?q?=EA=B0=95=20=EC=9D=B8=EC=9B=90=EC=9D=84=20=EC=A6=9D=EA=B0=80?=
 =?UTF-8?q?=EC=8B=9C=ED=82=A4=EB=8A=94=20=EA=B8=B0=EB=8A=A5=20=EC=B6=94?=
 =?UTF-8?q?=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                                | 2 +-
 .../java/nextstep/sessions/domain/EnrollmentCapacity.java    | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/docs/step2.md b/docs/step2.md
index 40d829a042..6eb4d954f2 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -21,7 +21,7 @@
 - [x] 이미지의 width와 height가 각각 300, 200 픽셀 이상인지 확인한다.
 - [x] 이미지의 width와 height 비율이 3:2인지 확인한다.
 - [x] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
-- [ ] 현재 수강 인원을 증가시킨다.
+- [x] 현재 수강 인원을 증가시킨다.
 - [ ] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
 - [ ] 수강 신청을 한다.
 - [ ] 강의 상태가 모집중인지 확인한다.
diff --git a/src/main/java/nextstep/sessions/domain/EnrollmentCapacity.java b/src/main/java/nextstep/sessions/domain/EnrollmentCapacity.java
index e35b890db1..0efc6444a4 100644
--- a/src/main/java/nextstep/sessions/domain/EnrollmentCapacity.java
+++ b/src/main/java/nextstep/sessions/domain/EnrollmentCapacity.java
@@ -17,6 +17,11 @@ public boolean isFull() {
         return currentEnrollment >= maxEnrollment;
     }
 
+    public void increaseEnrollment() {
+        validate();
+        currentEnrollment++;
+    }
+
     private void validate() {
         if (isFull()) {
             throw new IllegalStateException("정원이 초과되었습니다.");

From 2ecb6bdfc2a48314cc7942f6a42433beeee09936 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 16 Apr 2025 00:07:52 +0900
Subject: [PATCH 29/37] =?UTF-8?q?test=20=EA=B2=B0=EC=A0=9C=20=EA=B8=88?=
 =?UTF-8?q?=EC=95=A1=EA=B3=BC=20=EA=B0=95=EC=9D=98=20=EA=B8=88=EC=95=A1=20?=
 =?UTF-8?q?=EC=9D=BC=EC=B9=98=20=EC=97=AC=EB=B6=80=20=ED=85=8C=EC=8A=A4?=
 =?UTF-8?q?=ED=8A=B8=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../enrollment/domain/EnrollmentTest.java     | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 src/test/java/nextstep/enrollment/domain/EnrollmentTest.java

diff --git a/src/test/java/nextstep/enrollment/domain/EnrollmentTest.java b/src/test/java/nextstep/enrollment/domain/EnrollmentTest.java
new file mode 100644
index 0000000000..4dee15966e
--- /dev/null
+++ b/src/test/java/nextstep/enrollment/domain/EnrollmentTest.java
@@ -0,0 +1,22 @@
+package nextstep.enrollment.domain;
+
+import nextstep.payments.domain.Payment;
+import nextstep.sessions.domain.Session;
+import nextstep.users.domain.NsUser;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.*;
+
+class EnrollmentTest {
+    @Test
+    void 결제_금액_강의_금액_일치() {
+        new Enrollment(new NsUser(), new Session(10_000L), new Payment("user_id", 0L, 0L, 10_000L));
+    }
+
+    @Test
+    void 결제_금액_강의_금액_불일치() {
+        assertThatIllegalArgumentException().isThrownBy(() ->
+                        new Enrollment(new NsUser(), new Session(10_000L), new Payment("user_id", 0L, 0L, 20_000L)))
+                .withMessage("결제 금액이 수강료와 일치하지 않습니다.");
+    }
+}
\ No newline at end of file

From f547d74502a31b6760f350d141814e1bba2b6140 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 16 Apr 2025 00:08:27 +0900
Subject: [PATCH 30/37] =?UTF-8?q?feat=20=EC=88=98=EA=B0=95=EB=A3=8C?=
 =?UTF-8?q?=EC=99=80=20=EA=B2=B0=EC=A0=9C=20=EA=B8=88=EC=95=A1=EC=9D=B4=20?=
 =?UTF-8?q?=EC=9D=BC=EC=B9=98=ED=95=98=EB=8A=94=EC=A7=80=20=ED=99=95?=
 =?UTF-8?q?=EC=9D=B8=ED=95=98=EB=8A=94=20=EA=B8=B0=EB=8A=A5=20=EC=B6=94?=
 =?UTF-8?q?=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                 |  2 +-
 .../enrollment/domain/Enrollment.java         | 37 +++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/nextstep/enrollment/domain/Enrollment.java

diff --git a/docs/step2.md b/docs/step2.md
index 6eb4d954f2..89fbd43084 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -22,7 +22,7 @@
 - [x] 이미지의 width와 height 비율이 3:2인지 확인한다.
 - [x] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
 - [x] 현재 수강 인원을 증가시킨다.
-- [ ] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
+- [x] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
 - [ ] 수강 신청을 한다.
 - [ ] 강의 상태가 모집중인지 확인한다.
 - [ ] 결제 정보를 조회한다.
diff --git a/src/main/java/nextstep/enrollment/domain/Enrollment.java b/src/main/java/nextstep/enrollment/domain/Enrollment.java
new file mode 100644
index 0000000000..f08cc006b0
--- /dev/null
+++ b/src/main/java/nextstep/enrollment/domain/Enrollment.java
@@ -0,0 +1,37 @@
+package nextstep.enrollment.domain;
+
+import nextstep.payments.domain.Payment;
+import nextstep.sessions.domain.Session;
+import nextstep.users.domain.NsUser;
+
+import java.time.LocalDateTime;
+import java.util.Objects;
+
+public class Enrollment {
+    private final NsUser student;
+    private final Session session;
+    private final LocalDateTime enrolledAt;
+    private final Payment payment;
+
+    public Enrollment(NsUser student, Session session, Payment payment) {
+        validate(session, payment);
+        this.student = student;
+        this.session = session;
+        this.enrolledAt = LocalDateTime.now();
+        this.payment = payment;
+    }
+
+    private void validate(Session session, Payment payment) {
+        validatePaidCorrectly(session, payment);
+    }
+
+    private void validatePaidCorrectly(Session session, Payment payment) {
+        if (!hasPaidCorrectly(session, payment)) {
+            throw new IllegalArgumentException("결제 금액이 수강료와 일치하지 않습니다.");
+        }
+    }
+
+    private boolean hasPaidCorrectly(Session session, Payment payment) {
+        return Objects.equals(payment.amount(), session.price());
+    }
+}

From 835cf538a42c35768cb47f96db75a7541dffbeda Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 16 Apr 2025 00:27:24 +0900
Subject: [PATCH 31/37] =?UTF-8?q?test=20=EA=B0=95=EC=9D=98=20=EC=83=81?=
 =?UTF-8?q?=ED=83=9C=EC=97=90=20=EB=94=B0=EB=A5=B8=20=EC=88=98=EA=B0=95?=
 =?UTF-8?q?=EC=8B=A0=EC=B2=AD=20=ED=85=8C=EC=8A=A4=ED=8A=B8=20=EC=B6=94?=
 =?UTF-8?q?=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../enrollment/domain/EnrollmentTest.java      | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/test/java/nextstep/enrollment/domain/EnrollmentTest.java b/src/test/java/nextstep/enrollment/domain/EnrollmentTest.java
index 4dee15966e..2c4253ec62 100644
--- a/src/test/java/nextstep/enrollment/domain/EnrollmentTest.java
+++ b/src/test/java/nextstep/enrollment/domain/EnrollmentTest.java
@@ -2,21 +2,39 @@
 
 import nextstep.payments.domain.Payment;
 import nextstep.sessions.domain.Session;
+import nextstep.sessions.domain.SessionStatus;
 import nextstep.users.domain.NsUser;
+import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.*;
 
 class EnrollmentTest {
     @Test
+    @DisplayName("결제 금액이 강의 수강료와 일치하면 수강 신청에 성공한다.")
     void 결제_금액_강의_금액_일치() {
         new Enrollment(new NsUser(), new Session(10_000L), new Payment("user_id", 0L, 0L, 10_000L));
     }
 
     @Test
+    @DisplayName("결제 금액이 강의 수강료와 다르면 예외를 던진다.")
     void 결제_금액_강의_금액_불일치() {
         assertThatIllegalArgumentException().isThrownBy(() ->
                         new Enrollment(new NsUser(), new Session(10_000L), new Payment("user_id", 0L, 0L, 20_000L)))
                 .withMessage("결제 금액이 수강료와 일치하지 않습니다.");
     }
+
+    @Test
+    @DisplayName("강의 상태가 모집중이면 수강 신청이 가능하다.")
+    void 모집중_강의_수강_신청() {
+        new Enrollment(new NsUser(), new Session(SessionStatus.RECRUITING, 10_000L), new Payment("user_id", 0L, 0L, 10_000L));
+    }
+
+    @Test
+    @DisplayName("강의 상태가 모집중이 아니면 수강 신청 시 예외를 던진다.")
+    void 모집중_아닌_강의_수강_신청() {
+        assertThatIllegalArgumentException().isThrownBy(() ->
+            new Enrollment(new NsUser(), new Session(SessionStatus.CLOSED, 10_000L), new Payment("user_id", 0L, 0L, 10_000L)))
+                .withMessage("강의 상태가 모집중일 때만 수강 신청이 가능합니다.");
+    }
 }
\ No newline at end of file

From 31f9f94da5cee2770c68ddad63bf0b8a904db20a Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 16 Apr 2025 00:28:49 +0900
Subject: [PATCH 32/37] =?UTF-8?q?feat=20Session=20=ED=81=B4=EB=9E=98?=
 =?UTF-8?q?=EC=8A=A4=20=EC=83=9D=EC=84=B1=20=EB=B0=8F=20=EC=88=98=EA=B0=95?=
 =?UTF-8?q?=EC=8B=A0=EC=B2=AD=20=EC=8B=9C=20=EA=B0=95=EC=9D=98=20=EC=83=81?=
 =?UTF-8?q?=ED=83=9C=EA=B0=80=20=EB=AA=A8=EC=A7=91=EC=A4=91=EC=9D=B8?=
 =?UTF-8?q?=EC=A7=80=20=ED=99=95=EC=9D=B8=ED=95=98=EB=8A=94=20=EA=B8=B0?=
 =?UTF-8?q?=EB=8A=A5=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                 |  4 +-
 .../enrollment/domain/Enrollment.java         |  7 ++++
 .../nextstep/sessions/domain/Session.java     | 40 +++++++++++++++++++
 .../sessions/domain/SessionStatus.java        |  5 +++
 4 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 src/main/java/nextstep/sessions/domain/Session.java
 create mode 100644 src/main/java/nextstep/sessions/domain/SessionStatus.java

diff --git a/docs/step2.md b/docs/step2.md
index 89fbd43084..d722166f68 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -23,8 +23,8 @@
 - [x] 유료 강의의 강의 최대 수강 인원을 초과하는지 확인한다.
 - [x] 현재 수강 인원을 증가시킨다.
 - [x] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
-- [ ] 수강 신청을 한다.
-- [ ] 강의 상태가 모집중인지 확인한다.
+- [x] 수강 신청을 한다.
+- [x] 강의 상태가 모집중인지 확인한다.
 - [ ] 결제 정보를 조회한다.
 - [ ] 강의를 생성한다.
 - [ ] 강의 상태를 변경한다.
diff --git a/src/main/java/nextstep/enrollment/domain/Enrollment.java b/src/main/java/nextstep/enrollment/domain/Enrollment.java
index f08cc006b0..145ae78000 100644
--- a/src/main/java/nextstep/enrollment/domain/Enrollment.java
+++ b/src/main/java/nextstep/enrollment/domain/Enrollment.java
@@ -22,9 +22,16 @@ public Enrollment(NsUser student, Session session, Payment payment) {
     }
 
     private void validate(Session session, Payment payment) {
+        validateSessionStatus(session);
         validatePaidCorrectly(session, payment);
     }
 
+    private void validateSessionStatus(Session session) {
+        if (!session.isRecruiting()) {
+            throw new IllegalArgumentException("강의 상태가 모집중일 때만 수강 신청이 가능합니다.");
+        }
+    }
+
     private void validatePaidCorrectly(Session session, Payment payment) {
         if (!hasPaidCorrectly(session, payment)) {
             throw new IllegalArgumentException("결제 금액이 수강료와 일치하지 않습니다.");
diff --git a/src/main/java/nextstep/sessions/domain/Session.java b/src/main/java/nextstep/sessions/domain/Session.java
new file mode 100644
index 0000000000..ee81f021a7
--- /dev/null
+++ b/src/main/java/nextstep/sessions/domain/Session.java
@@ -0,0 +1,40 @@
+package nextstep.sessions.domain;
+
+public class Session {
+    private Long id;
+    private String title;
+    private SessionType type;
+    private SessionStatus status;
+    private SessionPeriod period;
+    private Image coverImage;
+    private EnrollmentCapacity enrollmentCapacity;
+    private Long price;
+
+    public Session(Long price) {
+        this.price = price;
+    }
+
+    public Session(SessionStatus status, Long price) {
+        this.status = status;
+        this.price = price;
+    }
+
+    public Session(Long id, String title, SessionType type, SessionStatus status, SessionPeriod period, Image coverImage, EnrollmentCapacity enrollmentCapacity, Long price) {
+        this.id = id;
+        this.title = title;
+        this.type = type;
+        this.status = status;
+        this.period = period;
+        this.coverImage = coverImage;
+        this.enrollmentCapacity = enrollmentCapacity;
+        this.price = price;
+    }
+
+    public Long price() {
+        return this.price;
+    }
+
+    public boolean isRecruiting() {
+        return status.equals(SessionStatus.RECRUITING);
+    }
+}
diff --git a/src/main/java/nextstep/sessions/domain/SessionStatus.java b/src/main/java/nextstep/sessions/domain/SessionStatus.java
new file mode 100644
index 0000000000..9e00695a04
--- /dev/null
+++ b/src/main/java/nextstep/sessions/domain/SessionStatus.java
@@ -0,0 +1,5 @@
+package nextstep.sessions.domain;
+
+public enum SessionStatus {
+    READY, RECRUITING, CLOSED
+}
\ No newline at end of file

From 7ecb687073e049918a4ad7b2227c09e4fd5c7f3c Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 16 Apr 2025 00:29:23 +0900
Subject: [PATCH 33/37] =?UTF-8?q?docs=20=ED=98=84=EC=9E=AC=20=ED=95=84?=
 =?UTF-8?q?=EC=9A=94=EC=97=86=EC=96=B4=EB=B3=B4=EC=9D=B4=EB=8A=94=20?=
 =?UTF-8?q?=EA=B8=B0=EB=8A=A5=20=EC=82=AD=EC=A0=9C?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/docs/step2.md b/docs/step2.md
index d722166f68..0ad18ffccd 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -24,9 +24,4 @@
 - [x] 현재 수강 인원을 증가시킨다.
 - [x] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
 - [x] 수강 신청을 한다.
-- [x] 강의 상태가 모집중인지 확인한다.
-- [ ] 결제 정보를 조회한다.
-- [ ] 강의를 생성한다.
-- [ ] 강의 상태를 변경한다.
-- [ ] 과정을 생성한다.
-- [ ] 과정에 강의를 추가한다.
\ No newline at end of file
+- [x] 강의 상태가 모집중인지 확인한다.
\ No newline at end of file

From db7209e9fa041e1d2073b3dda3221900ca242cb6 Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 16 Apr 2025 00:29:48 +0900
Subject: [PATCH 34/37] =?UTF-8?q?feat=20=EA=B2=B0=EC=A0=9C=20=EA=B8=88?=
 =?UTF-8?q?=EC=95=A1=EC=9D=84=20=EB=B0=98=ED=99=98=ED=95=98=EB=8A=94=20?=
 =?UTF-8?q?=EA=B8=B0=EB=8A=A5=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/step2.md                                       | 3 ++-
 src/main/java/nextstep/payments/domain/Payment.java | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/docs/step2.md b/docs/step2.md
index 0ad18ffccd..e65356cc1d 100644
--- a/docs/step2.md
+++ b/docs/step2.md
@@ -24,4 +24,5 @@
 - [x] 현재 수강 인원을 증가시킨다.
 - [x] 유료 강의의 수강료와 수강생이 결제한 금액이 일치하는지 확인한다.
 - [x] 수강 신청을 한다.
-- [x] 강의 상태가 모집중인지 확인한다.
\ No newline at end of file
+- [x] 강의 상태가 모집중인지 확인한다.
+- [x] 결제 금액을 반환한다.
\ No newline at end of file
diff --git a/src/main/java/nextstep/payments/domain/Payment.java b/src/main/java/nextstep/payments/domain/Payment.java
index 57d833f851..5af1257cbe 100644
--- a/src/main/java/nextstep/payments/domain/Payment.java
+++ b/src/main/java/nextstep/payments/domain/Payment.java
@@ -26,4 +26,8 @@ public Payment(String id, Long sessionId, Long nsUserId, Long amount) {
         this.amount = amount;
         this.createdAt = LocalDateTime.now();
     }
+
+    public Long amount() {
+        return this.amount;
+    }
 }

From cf74b39536ee1feb3d2cb773a1b6653e2f6aae6e Mon Sep 17 00:00:00 2001
From: JiEung2 <181757@jnu.ac.kr>
Date: Wed, 16 Apr 2025 00:30:32 +0900
Subject: [PATCH 35/37] =?UTF-8?q?feat=20SessionType=20=EC=B6=94=EA=B0=80?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/nextstep/sessions/domain/SessionType.java | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 src/main/java/nextstep/sessions/domain/SessionType.java

diff --git a/src/main/java/nextstep/sessions/domain/SessionType.java b/src/main/java/nextstep/sessions/domain/SessionType.java
new file mode 100644
index 0000000000..fb938b5332
--- /dev/null
+++ b/src/main/java/nextstep/sessions/domain/SessionType.java
@@ -0,0 +1,5 @@
+package nextstep.sessions.domain;
+
+public enum SessionType {
+    FREE, PAID
+}
\ No newline at end of file

From 6fe969cc428bb4b56889ba71850f8ad4c1e01561 Mon Sep 17 00:00:00 2001
From: jieung <jieung@lamilab.xyz>
Date: Thu, 17 Apr 2025 18:21:23 +0900
Subject: [PATCH 36/37] =?UTF-8?q?fix:=20MAX=5FSIZE=20=ED=91=9C=ED=98=84=20?=
 =?UTF-8?q?=EB=B0=A9=EC=8B=9D=20=EB=B3=80=EA=B2=BD=20=EB=B0=8F=20=EB=A7=A4?=
 =?UTF-8?q?=EC=A7=81=EB=84=98=EB=B2=84=20=EC=83=81=EC=88=98=20=EC=84=A0?=
 =?UTF-8?q?=EC=96=B8?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/main/java/nextstep/sessions/domain/Image.java | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/main/java/nextstep/sessions/domain/Image.java b/src/main/java/nextstep/sessions/domain/Image.java
index 253a2ef401..d643304d79 100644
--- a/src/main/java/nextstep/sessions/domain/Image.java
+++ b/src/main/java/nextstep/sessions/domain/Image.java
@@ -1,9 +1,10 @@
 package nextstep.sessions.domain;
 
 public class Image {
-    private static final Long MAX_SIZE_BYTES = 1_048_576L;
+    private static final Long MAX_SIZE_BYTES = 1024 * 1024L;
     private static final Float MIN_SIZE_WIDTH = 300F;
     private static final Float MIN_SIZE_HEIGHT = 200F;
+    private static final Float ASPECT_RATIO_TOLERANCE = 0.01f;
 
     private Long id;
     private Long sizeInBytes;
@@ -53,7 +54,7 @@ private void validateHeight(Float height) {
 
     private void validateAspectRatio(float width, float height) {
         float ratio = width / height;
-        if (Math.abs(ratio - 1.5) > 0.01) {
+        if (Math.abs(ratio - (MIN_SIZE_WIDTH / MIN_SIZE_HEIGHT)) > ASPECT_RATIO_TOLERANCE) {
             throw new IllegalArgumentException("이미지 비율은 3:2이어야 합니다.");
         }
     }

From fb64a352993ee99d11301a4b44d89129d05032e3 Mon Sep 17 00:00:00 2001
From: jieung <jieung@lamilab.xyz>
Date: Thu, 17 Apr 2025 18:21:55 +0900
Subject: [PATCH 37/37] =?UTF-8?q?fix:=20Date=20LocalDate=EB=A1=9C=20?=
 =?UTF-8?q?=EB=B3=80=EA=B2=BD=20=EB=B0=8F=20=EB=B3=80=EC=88=98=20final=20?=
 =?UTF-8?q?=EC=84=A0=EC=96=B8?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../java/nextstep/sessions/domain/SessionPeriod.java | 12 ++++++------
 .../nextstep/sessions/domain/SessionPeriodTest.java  | 10 +++++-----
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/main/java/nextstep/sessions/domain/SessionPeriod.java b/src/main/java/nextstep/sessions/domain/SessionPeriod.java
index d9aae583ab..b2031a4b1f 100644
--- a/src/main/java/nextstep/sessions/domain/SessionPeriod.java
+++ b/src/main/java/nextstep/sessions/domain/SessionPeriod.java
@@ -1,19 +1,19 @@
 package nextstep.sessions.domain;
 
-import java.util.Date;
+import java.time.LocalDate;
 
 public class SessionPeriod {
-    private Date startDate;
-    private Date endDate;
+    private final LocalDate startDate;
+    private final LocalDate endDate;
 
-    public SessionPeriod(Date startDate, Date endDate) {
+    public SessionPeriod(LocalDate startDate, LocalDate endDate) {
         validate(startDate, endDate);
         this.startDate = startDate;
         this.endDate = endDate;
     }
 
-    private void validate(Date startDate, Date endDate) {
-        if (startDate.after(endDate)) {
+    private void validate(LocalDate startDate, LocalDate endDate) {
+        if (startDate.isAfter(endDate)) {
             throw new IllegalArgumentException("시작일은 종료일보다 이전이어야 합니다.");
         }
     }
diff --git a/src/test/java/nextstep/sessions/domain/SessionPeriodTest.java b/src/test/java/nextstep/sessions/domain/SessionPeriodTest.java
index e5c0c5b03f..187c3a5ce9 100644
--- a/src/test/java/nextstep/sessions/domain/SessionPeriodTest.java
+++ b/src/test/java/nextstep/sessions/domain/SessionPeriodTest.java
@@ -5,16 +5,16 @@
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
-import java.util.Date;
+import java.time.LocalDate;
 
 public class SessionPeriodTest {
-    private Date earlier;
-    private Date later;
+    private LocalDate earlier;
+    private LocalDate later;
 
     @BeforeEach
     void setUp() {
-        this.earlier = new Date(2025, 1, 1);
-        this.later = new Date(2025, 3, 1);
+        this.earlier = LocalDate.of(2025, 1, 1);
+        this.later = LocalDate.of(2025, 3, 1);
     }
 
     @Test