create GameCommandRunner to extract business logic

src/main/kotlin/eventDemo/app/command/ErrorNotifier.kt

@@ -0,0 +1,29 @@
+package eventDemo.app.command
+
+import eventDemo.app.command.command.GameCommand
+import eventDemo.app.notification.ErrorNotification
+import eventDemo.app.notification.Notification
+import io.github.oshai.kotlinlogging.KotlinLogging
+import kotlinx.coroutines.channels.SendChannel
+
+typealias ErrorNotifier = suspend (String) -> Unit
+
+fun errorNotifier(
+    command: GameCommand,
+    channel: SendChannel<Notification>,
+): ErrorNotifier =
+    {
+        val logger = KotlinLogging.logger { }
+        ErrorNotification(message = it)
+            .let { notification ->
+                logger.atWarn {
+                    message = "Notification send ERROR: ${notification.message}"
+                    payload =
+                        mapOf(
+                            "notification" to notification,
+                            "command" to command,
+                        )
+                }
+                channel.send(notification)
+            }
+    }

src/main/kotlin/eventDemo/app/command/GameCommandHandler.kt

@@ -1,15 +1,8 @@
 package eventDemo.app.command
 
 import eventDemo.app.command.command.GameCommand
-import eventDemo.app.command.command.ICantPlayCommand
-import eventDemo.app.command.command.IWantToJoinTheGameCommand
-import eventDemo.app.command.command.IWantToPlayCardCommand
-import eventDemo.app.command.command.IamReadyToPlayCommand
 import eventDemo.app.entity.Player
-import eventDemo.app.event.GameEventHandler
 import eventDemo.app.event.event.GameEvent
-import eventDemo.app.event.projection.GameStateRepository
-import eventDemo.app.notification.ErrorNotification
 import eventDemo.app.notification.Notification
 import eventDemo.libs.command.CommandStreamChannelBuilder
 import io.github.oshai.kotlinlogging.KotlinLogging
@@ -22,9 +15,8 @@ import kotlinx.coroutines.channels.SendChannel
  * This action can be executing an action and produce a new [GameEvent] after verification.
  */
 class GameCommandHandler(
-    private val eventHandler: GameEventHandler,
-    private val gameStateRepository: GameStateRepository,
     private val commandStreamChannel: CommandStreamChannelBuilder<GameCommand>,
+    private val runner: GameCommandRunner,
 ) {
     private val logger = KotlinLogging.logger { }
 
@@ -48,30 +40,7 @@ class GameCommandHandler(
                     message = "Handle command: $command"
                     payload = mapOf("command" to command)
                 }
-                command.run(outgoingErrorChannelNotification)
+                runner.run(command, outgoingErrorChannelNotification)
             }
         }
-
-    private suspend fun GameCommand.run(outgoingErrorChannelNotification: SendChannel<Notification>) {
-        val gameState = gameStateRepository.get(payload.gameId)
-        val playerErrorNotifier = errorNotifier(outgoingErrorChannelNotification)
-
-        when (this) {
-            is IWantToPlayCardCommand -> run(gameState, playerErrorNotifier, eventHandler)
-            is IamReadyToPlayCommand -> run(gameState, playerErrorNotifier, eventHandler)
-            is IWantToJoinTheGameCommand -> run(gameState, playerErrorNotifier, eventHandler)
-            is ICantPlayCommand -> run(gameState, playerErrorNotifier, eventHandler)
-        }
-    }
 }
-
-fun errorNotifier(channel: SendChannel<Notification>): suspend (String) -> Unit =
-    {
-        val logger = KotlinLogging.logger { }
-        val notification = ErrorNotification(message = it)
-        logger.atWarn {
-            message = "Notification send ERROR: ${notification.message}"
-            payload = mapOf("notification" to notification)
-        }
-        channel.send(notification)
-    }

src/main/kotlin/eventDemo/app/command/GameCommandRunner.kt

@@ -0,0 +1,31 @@
+package eventDemo.app.command
+
+import eventDemo.app.command.command.GameCommand
+import eventDemo.app.command.command.ICantPlayCommand
+import eventDemo.app.command.command.IWantToJoinTheGameCommand
+import eventDemo.app.command.command.IWantToPlayCardCommand
+import eventDemo.app.command.command.IamReadyToPlayCommand
+import eventDemo.app.event.GameEventHandler
+import eventDemo.app.event.projection.GameStateRepository
+import eventDemo.app.notification.Notification
+import kotlinx.coroutines.channels.SendChannel
+
+class GameCommandRunner(
+    private val eventHandler: GameEventHandler,
+    private val gameStateRepository: GameStateRepository,
+) {
+    suspend fun run(
+        command: GameCommand,
+        outgoingErrorChannelNotification: SendChannel<Notification>,
+    ) {
+        val gameState = gameStateRepository.get(command.payload.gameId)
+        val errorNotifier = errorNotifier(command, outgoingErrorChannelNotification)
+
+        when (command) {
+            is IWantToPlayCardCommand -> command.run(gameState, errorNotifier, this.eventHandler)
+            is IamReadyToPlayCommand -> command.run(gameState, errorNotifier, this.eventHandler)
+            is IWantToJoinTheGameCommand -> command.run(gameState, errorNotifier, this.eventHandler)
+            is ICantPlayCommand -> command.run(gameState, errorNotifier, this.eventHandler)
+        }
+    }
+}

src/main/kotlin/eventDemo/app/command/command/ICantPlayCommand.kt

@@ -1,5 +1,6 @@
 package eventDemo.app.command.command
 
+import eventDemo.app.command.ErrorNotifier
 import eventDemo.app.entity.GameId
 import eventDemo.app.entity.Player
 import eventDemo.app.event.GameEventHandler
@@ -25,7 +26,7 @@ data class ICantPlayCommand(
 
     suspend fun run(
         state: GameState,
-        playerErrorNotifier: suspend (String) -> Unit,
+        playerErrorNotifier: ErrorNotifier,
         eventHandler: GameEventHandler,
     ) {
         if (state.currentPlayerTurn != payload.player) {

src/main/kotlin/eventDemo/app/command/command/IWantToJoinTheGameCommand.kt

@@ -1,5 +1,6 @@
 package eventDemo.app.command.command
 
+import eventDemo.app.command.ErrorNotifier
 import eventDemo.app.entity.GameId
 import eventDemo.app.entity.Player
 import eventDemo.app.event.GameEventHandler
@@ -26,7 +27,7 @@ data class IWantToJoinTheGameCommand(
 
     suspend fun run(
         state: GameState,
-        playerErrorNotifier: suspend (String) -> Unit,
+        playerErrorNotifier: ErrorNotifier,
         eventHandler: GameEventHandler,
     ) {
         val logger = KotlinLogging.logger {}

src/main/kotlin/eventDemo/app/command/command/IWantToPlayCardCommand.kt

@@ -1,5 +1,6 @@
 package eventDemo.app.command.command
 
+import eventDemo.app.command.ErrorNotifier
 import eventDemo.app.entity.Card
 import eventDemo.app.entity.GameId
 import eventDemo.app.entity.Player
@@ -27,7 +28,7 @@ data class IWantToPlayCardCommand(
 
     suspend fun run(
         state: GameState,
-        playerErrorNotifier: suspend (String) -> Unit,
+        playerErrorNotifier: ErrorNotifier,
         eventHandler: GameEventHandler,
     ) {
         if (!state.isStarted) {

src/main/kotlin/eventDemo/app/command/command/IamReadyToPlayCommand.kt

@@ -1,5 +1,6 @@
 package eventDemo.app.command.command
 
+import eventDemo.app.command.ErrorNotifier
 import eventDemo.app.entity.GameId
 import eventDemo.app.entity.Player
 import eventDemo.app.event.GameEventHandler
@@ -25,7 +26,7 @@ data class IamReadyToPlayCommand(
 
     suspend fun run(
         state: GameState,
-        playerErrorNotifier: suspend (String) -> Unit,
+        playerErrorNotifier: ErrorNotifier,
         eventHandler: GameEventHandler,
     ) {
         val playerExist: Boolean = state.players.contains(payload.player)

src/main/kotlin/eventDemo/configuration/ConfigureDI.kt

@@ -1,6 +1,7 @@
 package eventDemo.configuration
 
 import eventDemo.app.command.GameCommandHandler
+import eventDemo.app.command.GameCommandRunner
 import eventDemo.app.command.command.GameCommand
 import eventDemo.app.event.GameEventBus
 import eventDemo.app.event.GameEventHandler
@@ -40,6 +41,7 @@ val appKoinModule =
         }
 
         singleOf(::GameEventHandler)
+        singleOf(::GameCommandRunner)
         singleOf(::GameCommandHandler)
         singleOf(::PlayerNotificationEventListener)
     }

src/test/kotlin/eventDemo/app/command/GameCommandRunnerTest.kt

@@ -0,0 +1,8 @@
+package eventDemo.app.command
+
+import io.kotest.core.spec.style.FunSpec
+
+class GameCommandRunnerTest :
+    FunSpec({
+        test("run should run the correct command") { }
+    })