연장한 대출의 반납 일자 변경하는 책임을 Period로 변경

src/main/java/com/study/bookcafe/domain/borrow/Borrow.java

@@ -58,18 +58,9 @@ public boolean haveExtendableCount() {
      * 대출을 연장한다.
      */
     public void extend() {
-        // 연장 가능한 횟수가 남아있지 않으므로 불가
-        if (!haveExtendableCount()) return;
-
-        // 도서에 예약이 있으므로 불가
-        if (this.getBook().haveReservation()) return;
+        if (!canExtend()) return;
 
-        // 대출 연장이 가능한 날짜가 아니므로 불가
-        if (!isPassHalfofPeriod()) return;
-
-        LocalDate from = this.getPeriod().getFrom();
-        LocalDate extendedTo = this.getPeriod().getTo().plusWeeks(1);
-        Period extendedPeriod = new Period(from, extendedTo);
+        Period extendedPeriod = this.getPeriod().getExtended(this.getMember().getLevel());
 
         extendPeriod(extendedPeriod);
         increaseExtendCount();
@@ -91,4 +82,17 @@ public boolean isPassHalfofPeriod() {
 
         return now.isEqual(targetDate) || now.isAfter(targetDate);
     }
+
+    private boolean canExtend() {
+        // 연장 가능한 횟수가 남아있지 않으므로 불가
+        if (!haveExtendableCount()) return false;
+
+        // 도서에 예약이 있으므로 불가
+        if (this.getBook().haveReservation()) return false;
+
+        // 대출 연장이 가능한 날짜가 아니므로 불가
+        if (!isPassHalfofPeriod()) return false;
+
+        return true;
+    }
 }

src/main/java/com/study/bookcafe/domain/borrow/Period.java

@@ -35,4 +35,8 @@ public static Period of(@NonNull LocalDate from, Level level) {
         return new Period(from, level);
     }
 
+    public Period getExtended(Level level) {
+        return new Period(from, this.to.plusWeeks(level.getExtendPeriod()));
+    }
+
 }

src/main/java/com/study/bookcafe/domain/member/Level.java

@@ -4,23 +4,27 @@
 
 public enum Level {
 
-    LIBRARIAN(2, 10,null, 1, 1),          // 사서 회원
-    WORM(1, 5,null, 1, 1),                // 책벌레 회원
-    BASIC(0, 3, WORM, 1, 1);                    // 일반 회원
+    LIBRARIAN(2, 10,null, 1, 2, 1),          // 사서 회원
+    WORM(1, 5,null, 1, 1, 1),                // 책벌레 회원
+    BASIC(0, 3, WORM, 1, 1, 1);                    // 일반 회원
 
     private final int value;                      // 등급 값
     private final int maximumBorrowCount;         // 최대 대출 권수
     private final Level next;                     // 다음 등급
     private final int maximumExtendCount;         // 최대 대출 연장 횟수
+
+    @Getter
+    private final int borrowPeriod;               // 대출 기간 (week)
     @Getter
-    private final int borrowPeriod;         // 대출 연장 기간
+    private final int extendPeriod;               // 연장 기간 (week)
 
-    Level(int value, int maximumBorrowCount, Level next, int maximumExtendCount, int borrowPeriod) {
+    Level(int value, int maximumBorrowCount, Level next, int maximumExtendCount, int borrowPeriod, int extendPeriod) {
         this.value = value;
         this.maximumBorrowCount = maximumBorrowCount;
         this.next = next;
         this.maximumExtendCount = maximumExtendCount;
         this.borrowPeriod = borrowPeriod;
+        this.extendPeriod = extendPeriod;
     }
 
     /**

src/test/java/com/study/bookcafe/borrow/PeriodTest.java

@@ -1,6 +1,7 @@
 package com.study.bookcafe.borrow;
 
 import com.study.bookcafe.domain.borrow.Period;
+import com.study.bookcafe.domain.member.Level;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -29,4 +30,23 @@ public void ofExceptionTest() {
         Assertions.assertThrows(IllegalArgumentException.class, () -> new Period(date2, date1));
         Assertions.assertThrows(NullPointerException.class, () -> new Period(null, null));
     }
+
+    @Test
+    @DisplayName("회원 등급에 따라 대출 연장 기간을 확인한다,")
+    public void checkBorrowExtensionsPeriodByMemberShipLevel() {
+        LocalDate borrowDate = LocalDate.now();
+
+        Period basicExtendedPeriod = Period.of(borrowDate, Level.BASIC).getExtended(Level.BASIC);
+        Period wormExtendedPeriod = Period.of(borrowDate, Level.WORM).getExtended(Level.WORM);
+        Period librarianExtendedPeriod = Period.of(borrowDate, Level.LIBRARIAN).getExtended(Level.LIBRARIAN);
+
+        Period newBasicPeriod = new Period(borrowDate, borrowDate.plusWeeks(Level.BASIC.getBorrowPeriod()).plusWeeks(Level.BASIC.getExtendPeriod()));
+        Period newWormPeriod = new Period(borrowDate, borrowDate.plusWeeks(Level.WORM.getBorrowPeriod()).plusWeeks(Level.WORM.getExtendPeriod()));
+        Period newLibrarianPeriod = new Period(borrowDate, borrowDate.plusWeeks(Level.LIBRARIAN.getBorrowPeriod()).plusWeeks(Level.LIBRARIAN.getExtendPeriod()));
+
+        assertThat(basicExtendedPeriod).isEqualTo(newBasicPeriod);
+        assertThat(wormExtendedPeriod).isEqualTo(newWormPeriod);
+        assertThat(librarianExtendedPeriod).isEqualTo(newLibrarianPeriod);
+
+    }
 }