exports corrects

engine/core/board.js

@@ -2,15 +2,6 @@ import Cell from './cell.js';
 import * as Movement from './movement/index.js';
 import Piece, { PieceColor, PieceType } from './piece.js';
 
-export default  {
-    Cell,
-    Movement,
-    Piece,
-    PieceColor,
-    PieceType,
-    Board
-};
-
 /**
  * Represents the game board.
  */
@@ -93,4 +84,13 @@ class Board {
         this.setPiece(3, 7, new Piece(PieceColor.BLACK, PieceType.QUEEN, [Movement.QueenMove]));
         this.setPiece(4, 7, new Piece(PieceColor.BLACK, PieceType.KING, [Movement.KingMove]));
     }
-}
+}
+
+export default  {
+    Cell,
+    Movement,
+    Piece,
+    PieceColor,
+    PieceType,
+    Board
+};

engine/core/card.js

@@ -9,4 +9,6 @@ class Card {
         /** @type {Effect} */
         this.effect;
     }
-}
+}
+
+export default Card;

engine/core/cell.js

@@ -6,4 +6,6 @@ class Cell {
         /** @type {Piece|null} */
         this.piece = piece;
     }
-}
+}
+
+export default Cell;

engine/core/effect.js

@@ -1,3 +1,5 @@
 class Effect {
     constructor() {}
-}
+}
+
+export default Effect;

engine/core/game_state.js

@@ -59,4 +59,6 @@ class GameState {
         const team = color === PieceColor.WHITE ? this.whiteTeam : this.blackTeam;
         return team.hasKing();
     }
-}
+}
+
+export default GameState;

engine/core/hand.js

@@ -26,4 +26,6 @@ class Hand {
             return c;
         }
     }
-}
+}
+
+export default Hand;

engine/core/piece.js

@@ -44,4 +44,6 @@ class Piece {
     getType() {
         return this.type;
     }
-}
+}
+
+export default Piece;

engine/core/stack.js

@@ -45,4 +45,6 @@ class Stack {
             [this.stack[index], this.stack[randomIndex]] = [this.stack[randomIndex], this.stack[index]];
         }
     }
-}
+}
+
+export default Stack;

engine/core/team.js

@@ -24,4 +24,6 @@ class Team {
     hasKing() {
         return this.king !== null;
     }
-}
+}
+
+export default Team;