refactor : 로또 도메인 리팩토링 진행 (#22)

* refactor : LottoTicket 내부에서만 LottoGame 접근 할 수 있도록 수정

* refactor : LottoGame 인스턴스로 수동인지 자동인지 확인 가능하도록 수정

* test : LottoTicket 테스트 코드 작성

Author: this-is-spear

src/main/kotlin/controller/LottoApp.kt

@@ -1,7 +1,6 @@
 package controller
 
 import model.lotto.LottoCount
-import model.lotto.LottoGameGenerator
 import model.lotto.LottoNumber
 import model.lotto.LottoNumbers
 import model.lotto.LottoTickets
@@ -50,12 +49,10 @@ class LottoApp(private val inputView: InputView, private val outputView: OutputV
         return LottoCount.of(manualCount, money)
     }
 
-    // FIXME: 테스트 용이성이나 객체지향 관점에서 Ticket 은 LottoTicket 이 직접 생성해줘야하지 않을까요?
     private fun generateLottoTicket(lottoCount: LottoCount): LottoTickets {
         val manualNumbers = requestManualLottoNumbers(lottoCount.manualCount)
-        val manualGames = LottoGameGenerator.generate(manualNumbers)
-        val autoGames = LottoGameGenerator.generate(lottoCount.autoCount)
-        return LottoTickets.createWithGames(manualGames + autoGames)
+        val autoNumbers = requestAutoLottoNumbers(lottoCount.autoCount)
+        return LottoTickets.of(manualNumbers, autoNumbers)
     }
 
     private fun requestManualLottoNumbers(manualCount: Int): List<LottoNumbers> {
@@ -64,4 +61,15 @@ class LottoApp(private val inputView: InputView, private val outputView: OutputV
             LottoNumbers.from(inputView.requestLottoNumber())
         }
     }
+
+    private fun requestAutoLottoNumbers(autoCount: Int): List<LottoNumbers> {
+        val allPossibleNumbers = (1..45).toList()
+        return List(autoCount) {
+            val selectedNumbers = allPossibleNumbers
+                .shuffled()
+                .take(6)
+                .sorted()
+            LottoNumbers.from(selectedNumbers)
+        }
+    }
 }

src/main/kotlin/model/lotto/LottoGame.kt

@@ -1,41 +1,10 @@
 package model.lotto
 
-enum class TicketType {
-    Manual,
-    Auto,
-}
-
-data class LottoGame(
-    val numbers: LottoNumbers,
-    val type: TicketType,
-) {
-    companion object {
-        fun of(
-            numbers: LottoNumbers,
-            type: TicketType,
-        ): LottoGame {
-            return LottoGame(numbers, type)
-        }
-    }
+sealed class LottoGame(val numbers: LottoNumbers) {
+    class Manual(manualNumbers: LottoNumbers) : LottoGame(manualNumbers)
+    class Auto(autoNumbers: LottoNumbers) : LottoGame(autoNumbers)
 
     override fun toString(): String {
         return numbers.toString()
     }
 }
-
-object LottoGameGenerator {
-    fun generate(count: Int): List<LottoGame> {
-        val allPossibleNumbers = (1..45).toList()
-        return List(count) {
-            val selectedNumbers = allPossibleNumbers.shuffled().take(6).sorted()
-            val lottoNumbers = LottoNumbers.from(selectedNumbers)
-            LottoGame.of(lottoNumbers, TicketType.Auto)
-        }
-    }
-
-    fun generate(manualNumbers: List<LottoNumbers>): List<LottoGame> {
-        return manualNumbers.map { lottoNumbers ->
-            LottoGame.of(lottoNumbers, TicketType.Manual)
-        }
-    }
-}

src/main/kotlin/model/lotto/LottoTicket.kt

@@ -1,10 +1,12 @@
 package model.lotto
 
+internal const val REQUIRED_LEAST_ONE_GAME = "최소 한 게임 이상 포함되어야 합니다."
+internal const val REQUIRED_MAXIMUM_FIVE_GAME = "최대 다섯 게임만 포함될 수 있습니다."
+
 class LottoTicket(val games: List<LottoGame>) {
-    companion object {
-        fun of(games: List<LottoGame>): LottoTicket {
-            return LottoTicket(games)
-        }
+    init {
+        require(games.isNotEmpty()) { REQUIRED_LEAST_ONE_GAME }
+        require(games.size < 6) { REQUIRED_MAXIMUM_FIVE_GAME }
     }
 
     override fun toString(): String {

src/main/kotlin/model/lotto/LottoTickets.kt

@@ -5,12 +5,10 @@ class LottoTickets(
     val elements: List<LottoTicket>,
 ) {
     companion object {
-        fun of(elements: List<LottoTicket>): LottoTickets {
-            return LottoTickets(elements)
-        }
-
-        fun createWithGames(elements: List<LottoGame>): LottoTickets {
-            val tickets = elements.chunked(5).map { LottoTicket.of(it) }
+        fun of(manualNumbers: List<LottoNumbers>, autoNumbers: List<LottoNumbers>): LottoTickets {
+            val manualGames = manualNumbers.map { LottoGame.Manual(it) }.toList()
+            val autoGames = autoNumbers.map { LottoGame.Auto(it) }.toList()
+            val tickets = (manualGames + autoGames).chunked(5).map { LottoTicket(it) }
             return LottoTickets(tickets)
         }
     }

src/main/kotlin/view/OutputView.kt

@@ -2,7 +2,6 @@ package view
 
 import model.lotto.LottoGame
 import model.lotto.LottoTickets
-import model.lotto.TicketType
 
 internal const val INPUT_MONEY_MESSAGE = "구입금액을 입력해 주세요."
 internal const val INPUT_MANUAL_INPUT_MESSAGE = "수동으로 구매할 로또 게임 수를 입력해 주세요."
@@ -33,8 +32,8 @@ class OutputView {
     }
 
     private fun printLottoGames(lottoGames: List<LottoGame>) {
-        val manualGames = lottoGames.filter { it.type == TicketType.Manual }
-        val autoGames = lottoGames.filter { it.type == TicketType.Auto }
+        val manualGames = lottoGames.filterIsInstance<LottoGame.Manual>()
+        val autoGames = lottoGames.filterIsInstance<LottoGame.Auto>()
         println("수동으로 ${manualGames.size}게임, 자동으로 ${autoGames.size}게임을 구매하셨습니다.")
         if (manualGames.isNotEmpty()) {
             println("수동으로 구매한 로또 번호")

src/test/kotlin/model/FixtureGenerator.kt

@@ -0,0 +1,18 @@
+package model
+
+import model.lotto.LottoGame
+import model.lotto.LottoNumbers
+
+fun generateFixtureLottoGames(count: Int): List<LottoGame> {
+    if (count == 0) {
+        return emptyList()
+    }
+
+    return List(count) {
+        val selectedNumbers = (1..45).toList()
+            .shuffled()
+            .take(6)
+            .sorted()
+        LottoGame.Auto(LottoNumbers.from(selectedNumbers))
+    }
+}

src/test/kotlin/model/lotto/LottoGameGeneratorTest.kt

@@ -5,24 +5,18 @@ import io.kotest.matchers.shouldBe
 
 class LottoGameTest : FreeSpec(
     {
-        "LottoGame 생성" - {
-            "주어진 LottoNumbers 와 TicketType 을 가진 LottoGame 을 반환" {
-                val numbers = LottoNumbers.from(listOf(1, 2, 3, 4, 5, 6))
-                val ticketType = TicketType.Manual
-                val ticket = LottoGame.of(numbers, ticketType)
+        "ManualLotto 생성" {
+            val numbers = LottoNumbers.from(listOf(1, 2, 3, 4, 5, 6))
+            val ticket = LottoGame.Manual(numbers)
 
-                ticket.numbers shouldBe numbers
-                ticket.type shouldBe ticketType
-            }
+            ticket.numbers shouldBe numbers
         }
 
-        "LottoGame 출력" - {
-            "LottoGame 의 numbers 필드를 문자열화 하여 반환" {
-                val numbers = LottoNumbers.from(listOf(1, 2, 3, 4, 5, 6))
-                val ticket = LottoGame.of(numbers, TicketType.Manual)
+        "AutoLotto 출력" {
+            val numbers = LottoNumbers.from(listOf(1, 2, 3, 4, 5, 6))
+            val ticket = LottoGame.Auto(numbers)
 
-                ticket.toString() shouldBe numbers.toString()
-            }
+            ticket.toString() shouldBe numbers.toString()
         }
     },
 )

src/test/kotlin/model/lotto/LottoGameTest.kt

@@ -0,0 +1,38 @@
+package model.lotto
+
+import io.kotest.assertions.throwables.shouldThrowExactly
+import io.kotest.core.spec.style.FreeSpec
+import io.kotest.matchers.shouldBe
+import model.generateFixtureLottoGames
+
+class LottoTicketTest : FreeSpec(
+    {
+        "LottoTicket을 생성할 때" - {
+            "1개의 로또 게임이 포함 될 수 있다." - {
+                val count = 1
+                val ticket = LottoTicket(generateFixtureLottoGames(count))
+                ticket.games.size shouldBe count
+            }
+
+            "5개의 로또 게임이 포함 될 수 있다." - {
+                val count = 5
+                val ticket = LottoTicket(generateFixtureLottoGames(count))
+                ticket.games.size shouldBe count
+            }
+
+            "로또 게임이 없으면 안된다." - {
+                val games = generateFixtureLottoGames(0)
+                println(games)
+                shouldThrowExactly<IllegalArgumentException> {
+                    LottoTicket(emptyList())
+                }.message shouldBe REQUIRED_LEAST_ONE_GAME
+            }
+
+            "로또 게임이 6개 이상 포함되면 안된다." - {
+                shouldThrowExactly<IllegalArgumentException> {
+                    LottoTicket(generateFixtureLottoGames(6))
+                }.message shouldBe REQUIRED_MAXIMUM_FIVE_GAME
+            }
+        }
+    },
+)