fix(plugin): add proper cloning of boards fields

Author: SKoschnicke

plugin/src/shared/sc/plugin2020/Board.kt

@@ -124,7 +124,7 @@ data class Board(
                     throw IndexOutOfBoundsException()
                 x = f.coordinates.x + SHIFT
                 y = f.coordinates.y + SHIFT
-                gameField[x][y] = f
+                gameField[x][y] = f.clone()
             }
             return gameField
         }

plugin/src/shared/sc/plugin2020/Field.kt

@@ -61,6 +61,8 @@ class Field(
 
     constructor(field: Field): this(field.x, field.y, field.z, field.pieces.toCollection(Stack()), field.isObstructed)
 
+    public override fun clone() = Field(this)
+    
     override fun equals(other: Any?): Boolean {
         if(this === other) return true
         if(javaClass != other?.javaClass)

plugin/src/test/sc/plugin2020/CloneTest.kt

@@ -1,5 +1,6 @@
 package sc.plugin2020
 
+import io.kotlintest.matchers.types.shouldNotBeSameInstanceAs
 import io.kotlintest.shouldBe
 import io.kotlintest.specs.StringSpec
 import sc.framework.plugins.Player
@@ -8,16 +9,25 @@ import sc.shared.PlayerColor
 class CloneTest: StringSpec({
     "clone Player" {
         val player = Player(PlayerColor.RED, "aPlayer")
-        player.clone() shouldBe player
+        val clone = player.clone()
+        clone shouldBe player
+        clone shouldNotBeSameInstanceAs player
     }
     "clone Board" {
         val board = Board()
-        board.clone() shouldBe board
+        board.getField(0, 0, 0).pieces.add(Piece(PlayerColor.RED, PieceType.BEETLE))
+        val clone = board.clone()
+        clone shouldBe board
+        clone shouldNotBeSameInstanceAs board
+        clone.getField(0, 0, 0) shouldNotBeSameInstanceAs board.getField(0, 0, 0)
+        // note that the individual pieces are immutable and don't need to be cloned, only the stack which holds them
+        clone.getField(0, 0, 0).pieces shouldNotBeSameInstanceAs board.getField(0, 0, 0).pieces
     }
     "clone GameState" {
         val state = GameState(blue = Player(PlayerColor.BLUE, "aBluePlayer"), turn = 5)
         val clone = state.clone()
         clone shouldBe state
+        clone shouldNotBeSameInstanceAs state
         clone.getDeployedPieces(PlayerColor.RED) shouldBe state.getDeployedPieces(PlayerColor.RED)
     }
 })