[#21] Improve exceptions

src/main/kotlin/app/demo/MeleeCombatDemo.kt

@@ -2,6 +2,7 @@ package app.demo
 
 import game.CannotTargetSelf
 import game.GameRenderer
+import game.NoActionPointsException
 import game.OutOfRangeException
 import game.action.*
 import game.component.*
@@ -18,7 +19,6 @@ import game.rpg.character.skill.Skill
 import game.rpg.character.skill.SkillManager
 import game.rpg.character.skill.SkillUsage
 import game.rpg.check.Checker
-import game.rpg.time.NoActionPointsException
 import game.rpg.time.TimeSystem
 import game.rpg.time.TurnData
 import javafx.application.Application

src/main/kotlin/game/Exceptions.kt

@@ -1,4 +1,6 @@
 package game
 
-class CannotTargetSelf : Exception()
-class OutOfRangeException : Exception()
+data class CannotTargetSelf(val entity: Int) : Exception()
+data class NoActionPointsException(val entity: Int) : Exception()
+data class NoMovementPointsException(val entity: Int) : Exception()
+data class OutOfRangeException(val distance: Int) : Exception()

src/main/kotlin/game/reducer/action/MoveReducer.kt

@@ -77,7 +77,7 @@ private fun move(
     val newBody = updateBody(body, walkable.position)
     val newBodyStorage = bodyStorage.updateAndRemove(mapOf(entity to newBody))
 
-    val newTurnData = turnData.reduceMovementPoints()
+    val newTurnData = turnData.reduceMovementPoints(entity)
 
     return state.copy(listOf(newBodyStorage), listOf(newMap, newTurnData))
 }

src/main/kotlin/game/reducer/action/UseAbilityReducer.kt

@@ -38,7 +38,7 @@ val USE_ABILITY_REDUCER: Reducer<Action, EcsState> = a@{ state, action ->
     val target =
         map.entities[action.position] ?: throw  IllegalStateException("No target at position ${action.position}")
 
-    if (action.entity == target) throw CannotTargetSelf()
+    if (action.entity == target) throw CannotTargetSelf(target)
 
     val (entityStatistics, targetStatistics) = state.getStorage<Statistics>().getList(action.entity, target)
 
@@ -59,7 +59,7 @@ val USE_ABILITY_REDUCER: Reducer<Action, EcsState> = a@{ state, action ->
         is MeleeAttack -> {
             val distance = calculateDistanceToPosition(map.size, body, action.position)
 
-            if (distance > ability.reach) throw OutOfRangeException()
+            if (distance > ability.reach) throw OutOfRangeException(distance)
 
             val attackRank = entityStatistics.getRank(ability.skill)
             val defenseRank = targetStatistics.getRank(defense.skill)

src/main/kotlin/game/rpg/time/TurnData.kt

@@ -1,5 +1,7 @@
 package game.rpg.time
 
+import game.NoActionPointsException
+import game.NoMovementPointsException
 import game.component.Combat
 import game.component.Statistics
 import game.rpg.character.skill.Skill
@@ -16,8 +18,8 @@ data class TurnData(
 
     fun isFinished() = movementPoints <= 0 && actionPoints <= 0
 
-    fun reduceMovementPoints(): TurnData {
-        require(movementPoints > 0) { "Can not reduce movement points below 0!" }
+    fun reduceMovementPoints(entity: Int): TurnData {
+        if (movementPoints <= 0) throw NoMovementPointsException(entity)
         return copy(movementPoints = movementPoints - 1)
     }
 

src/test/kotlin/game/rpg/time/TurnDataTest.kt

@@ -2,6 +2,8 @@ package game.rpg.time
 
 import assertk.assertThat
 import assertk.assertions.isEqualTo
+import game.NoActionPointsException
+import game.NoMovementPointsException
 import game.component.Combat
 import game.component.Statistics
 import game.rpg.character.skill.Skill
@@ -16,6 +18,8 @@ import kotlin.test.assertTrue
 
 class TurnDataTest {
 
+    private val entity = 99
+
     @Test
     fun `Test constructor`() {
         assertThat(TurnData(6, 2)).isEqualTo(TurnData(6, 6, 2, 2))
@@ -52,22 +56,24 @@ class TurnDataTest {
 
         @Test
         fun `Reduce movement points`() {
-            val data = TurnData(6, 1).reduceMovementPoints()
+            val data = TurnData(6, 1).reduceMovementPoints(entity)
             assertThat(data).isEqualTo(TurnData(5, 6, 1, 1))
         }
 
         @Test
         fun `Reduce 0 movement points`() {
-            assertFailsWith<IllegalArgumentException> { TurnData(0, 1).reduceMovementPoints() }
+            val exception = assertFailsWith<NoMovementPointsException> {
+                TurnData(0, 1).reduceMovementPoints(entity)
+            }
+
+            assertThat(exception).isEqualTo(NoMovementPointsException(entity))
         }
 
     }
 
     @Nested
     inner class ReduceActionPoints {
 
-        val entity = 99
-
         @Test
         fun `Reduce action points`() {
             val data = TurnData(6, 2).reduceActionPoints(entity)