Apply insufficient material check when both players have bishops

src/main/scala/InsufficientMatingMaterial.scala

@@ -11,8 +11,8 @@ object InsufficientMatingMaterial {
   def nonKingPieces(board: Board) = board.pieces.filter(_._2.role != King).toList
 
   /**
-   * Returns true when the only non-king pieces that remain are bishops that cannot
-   * capture each other and cannot checkmate (in atomic chess).
+   * Returns true when remaining non-King pieces are only bishops that cannot
+   * capture each other and cannot checkmate
    */
   def bishopsOnDifferentColor(board: Board) = {
     val notKingPieces = nonKingPieces(board)
@@ -63,7 +63,7 @@ object InsufficientMatingMaterial {
     board rolesOf color filter (King !=) match {
       case Nil => true
       case List(Knight) => board rolesOf !color filter (King !=) filter (Queen !=) isEmpty
-      case List(Bishop) => board rolesOf !color filter (King !=) filter (Queen !=) filter (Rook !=) isEmpty
+      case List(Bishop) => (board rolesOf !color filter (King !=) filter (Queen !=) filter (Rook !=) filter (Bishop !=) isEmpty) || bishopsOnDifferentColor(board)
       case _ => false
     }
 }

src/test/scala/VariantTest.scala

@@ -15,7 +15,7 @@ class VariantTest extends ChessTest {
     }
 
     "Identify insufficient mating material when called (bishop)." in {
-      val position = "8/3k4/2q5/8/8/K1B5/8/8 w - -"
+      val position = "krq5/bqqq4/qqr5/1qq5/8/8/8/3qB2K b - -"
       val game = fenToGame(position, Standard)
 
       game should beSuccess.like {
@@ -25,14 +25,13 @@ class VariantTest extends ChessTest {
     }
 
     "Identify insufficient mating material when called (knight)." in {
-      val position = "8/3k4/2q5/8/8/K1N5/8/8 w - -"
+      val position = "8/3k4/2q5/8/8/K1N5/8/8 b - -"
       val game = fenToGame(position, Standard)
 
       game should beSuccess.like {
         case game =>
           game.situation.board.variant.insufficientWinningMaterial(game.situation.board, Color.white) must beTrue
       }
-
     }
   }