hack to fix crashes when a user connects to a game twice using the same browser

Reviewed-on: #15

.vscode/launch.json

@@ -1,15 +0,0 @@
-{
-	// Use IntelliSense to learn about possible attributes.
-	// Hover to view descriptions of existing attributes.
-	// For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
-	"version": "0.2.0",
-	"configurations": [
-		{
-			"name": "Launch Package",
-			"type": "go",
-			"request": "launch",
-			"mode": "debug",
-			"program": "${workspaceFolder}/main.go"
-		}
-	]
-}

api/handler/handler.go

@@ -30,7 +30,6 @@ func HostGameHandler(c *gin.Context) {
 	passphrase := lobby.Passphrase.String()
 	info := api.PlayerInfo{
 		PlayerID:   &player.Uuid,
-		LobbyID:    &lobby.Uuid,
 		Passphrase: &passphrase,
 	}
 	c.Header("Access-Control-Allow-Origin", "*")
@@ -54,14 +53,14 @@ func GetLobbyForPassphraseHandler(c *gin.Context) {
 		return
 	}
 
-	lobbyInfo := api.LobbyInfo{
+	passphrase := api.Passphrase{
-		ID: &lobby.Uuid,
+		Value: (*string)(&lobby.Passphrase),
 	}
 
-	c.IndentedJSON(http.StatusOK, lobbyInfo)
+	c.Header("Access-Control-Allow-Origin", "*")
+	c.IndentedJSON(http.StatusOK, passphrase)
 }
 
-// TODO: this will be replaced by the JoinGameHandler()
 func JoinPrivateGame(c *gin.Context) {
 	limiter.Take()
 
@@ -69,27 +68,29 @@ func JoinPrivateGame(c *gin.Context) {
 	err := c.ShouldBindJSON(&req)
 	if err != nil || req.Passphrase == nil || *req.Passphrase == "" {
 		c.IndentedJSON(http.StatusNotFound, req)
+		return
 	}
 
 	u := lobbies.GetUsher()
 
-	if req.Passphrase != nil &&
+	if req.PlayerID != nil { //is reconnect
-		*req.Passphrase != "" &&
-		req.PlayerID != nil &&
-		req.LobbyID != nil { //is reconnect
 		lobby := u.FindExistingPrivateLobby(utils.Passphrase(*req.Passphrase))
-		_, found := lobby.GetPlayerByUUID(*req.PlayerID)
+		var found bool
+		if lobby != nil {
+			_, found = lobby.GetPlayerByUUID(*req.PlayerID)
+		}
 		if found {
+			c.Header("Access-Control-Allow-Origin", "*")
 			c.IndentedJSON(
 				http.StatusOK,
 				api.PlayerInfo{
 					PlayerID:   req.PlayerID,
-					LobbyID:    req.LobbyID,
 					Passphrase: req.Passphrase,
 				})
 			return
 		} else {
 			c.IndentedJSON(http.StatusNotFound, req)
+			return
 		}
 	}
 
@@ -107,7 +108,6 @@ func JoinPrivateGame(c *gin.Context) {
 
 	info := api.PlayerInfo{
 		PlayerID:   &player.Uuid,
-		LobbyID:    &lobby.Uuid,
 		Passphrase: req.Passphrase,
 	}
 	c.Header("Access-Control-Allow-Origin", "*")
@@ -117,25 +117,22 @@ func JoinPrivateGame(c *gin.Context) {
 func JoinGameHandler(c *gin.Context) {
 	limiter.Take()
 
-	id := c.Param("id")
+	passphrase := api.Passphrase{}
-	idAsUUID, err := uuid.Parse(id)
+	err := c.ShouldBindJSON(&passphrase)
 	if err != nil {
 		c.IndentedJSON(http.StatusBadRequest, nil)
 		return
 	}
 
-	passphrase := api.Passphrase{}
-	c.ShouldBindJSON(&passphrase)
-
 	u := lobbies.GetUsher()
-	lobby := u.GetLobbyByID(idAsUUID)
+	lobby := u.FindExistingPrivateLobby(utils.Passphrase(*passphrase.Value))
 	if lobby == nil {
 		c.IndentedJSON(http.StatusNotFound, nil)
 		return
 	}
 
-	lobbyInfo := api.LobbyInfo{
+	lobbyInfo := api.Passphrase{
-		ID: &lobby.Uuid,
+		Value: (*string)(&lobby.Passphrase),
 	}
 
 	c.IndentedJSON(http.StatusOK, lobbyInfo)

api/handler/handler_test.go

@@ -9,13 +9,12 @@ import (
 	"testing"
 
 	"github.com/gin-gonic/gin"
-	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 )
 
 func Test_GetLobbyFromPassphraseHandler(t *testing.T) {
 	var passphraseURLParameter string
-	var hostedLobbyId uuid.UUID
+	var receivedPhrase string
 
 	t.Run("host a lobby", func(t *testing.T) {
 		r1 := httptest.NewRecorder()
@@ -30,8 +29,7 @@ func Test_GetLobbyFromPassphraseHandler(t *testing.T) {
 		err := json.Unmarshal(r1.Body.Bytes(), &playerInfo)
 		assert.NoError(t, err)
 
-		receivedPhrase := *playerInfo.Passphrase
+		receivedPhrase = *playerInfo.Passphrase
-		hostedLobbyId = *playerInfo.LobbyID
 
 		passphrase := utils.NewPassphraseFromString(receivedPhrase)
 		passphraseURLParameter = passphrase.AsURLParam()
@@ -48,10 +46,10 @@ func Test_GetLobbyFromPassphraseHandler(t *testing.T) {
 
 		engine.ServeHTTP(r2, getLobbyRequest)
 
-		lobbyInfo := api.LobbyInfo{}
+		passhrase := api.Passphrase{}
-		err := json.Unmarshal(r2.Body.Bytes(), &lobbyInfo)
+		err := json.Unmarshal(r2.Body.Bytes(), &passhrase)
 		assert.NoError(t, err)
 
-		assert.Equal(t, hostedLobbyId, *lobbyInfo.ID)
+		assert.Equal(t, http.StatusOK, r2.Code)
 	})
 }

api/handler/websocket.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"log"
 	"mchess_server/api"
+	"mchess_server/utils"
 	"net/http"
 
 	"mchess_server/lobbies"
@@ -23,7 +24,6 @@ var upgrader = gorillaws.Upgrader{
 func RegisterWebSocketConnection(c *gin.Context) {
 	limiter.Take()
 
-	log.Println(c.Request)
 	conn, err := upgrader.Upgrade(c.Writer, c.Request, nil)
 	if err != nil {
 		log.Println(err)
@@ -55,7 +55,7 @@ func waitForAndHandlePlayerID(ctx context.Context, conn *gorillaws.Conn) {
 		return
 	}
 
-	lobby := lobbies.GetLobbyRegistry().GetLobbyByUUID(*info.LobbyID)
+	lobby := lobbies.GetLobbyRegistry().GetLobbyByPassphrase(utils.NewPassphraseFromString(*info.Passphrase))
 	if lobby == nil {
 		conn.WriteMessage(msgType, []byte("lobby not found"))
 		conn.Close()
@@ -68,11 +68,13 @@ func waitForAndHandlePlayerID(ctx context.Context, conn *gorillaws.Conn) {
 		conn.Close()
 		return
 	}
-	if player.Conn.HasWebsocketConnection() {
+
-		player.Conn.Close("closing existing connection")
-	}
 	lobby.Game.SetWebsocketConnectionFor(ctx, player, conn)
-	log.Println("player after setting connection: ", player)
+
+	log.Println("player after setting connection: ")
+	log.Println("id: ", player.Uuid)
+	log.Println("color: ", player.GetColor())
+	log.Println("Connection: ", player.Conn.ID)
 }
 
 func ConnectWsForGame(c *gin.Context) {

api/lobby_info.go

@@ -1,7 +0,0 @@
-package api
-
-import "github.com/google/uuid"
-
-type LobbyInfo struct {
-	ID *uuid.UUID `json:"id,omitempty"`
-}

api/player_info.go

@@ -4,6 +4,5 @@ import "github.com/google/uuid"
 
 type PlayerInfo struct {
 	PlayerID   *uuid.UUID `json:"playerID,omitempty"`
-	LobbyID    *uuid.UUID `json:"lobbyID,omitempty"`
 	Passphrase *string    `json:"passphrase,omitempty"`
 }

chess/game.go

@@ -58,8 +58,8 @@ func (game Game) GetPlayer2() *Player {
 }
 
 func (game *Game) prepare() {
-	game.players[0].color = types.White
+	game.players[0].SetColor(types.White)
-	game.players[1].color = types.Black
+	game.players[1].SetColor(types.Black)
 
 	game.currentTurnPlayer = game.GetPlayer1()
 
@@ -99,13 +99,13 @@ func (game *Game) Handle() {
 			game.gameState = PlayerToMove
 
 		case PlayerToMove:
-			log.Println("with ", game.currentTurnPlayer.GetPlayerColor(), " to move")
+			log.Println("with ", game.currentTurnPlayer.GetColor(), " to move")
 			receivedMove, err = game.currentTurnPlayer.ReadMove()
 			if err != nil {
 				log.Println("Error while reading message:", err)
 				return
 			}
-			log.Println("Player ", game.currentTurnPlayer, " moved:\n", receivedMove)
+			log.Println("Player ", game.currentTurnPlayer.color.String(), " moved:\n", receivedMove)
 
 			game.gameState = CheckMove
 		case CheckMove:
@@ -117,7 +117,7 @@ func (game *Game) Handle() {
 					log.Println("Error marshalling 'colorDetermined' message for player 1", err)
 					return
 				}
-				game.currentTurnPlayer.writeMessage(invalidMoveMessage)
+				game.currentTurnPlayer.writeMessage(string(invalidMoveMessage))
 				game.gameState = PlayerToMove
 				continue
 			}
@@ -157,6 +157,14 @@ func (game *Game) AddPlayersToGame(player *Player) {
 	game.players = append(game.players, player)
 }
 
+func (game *Game) AreBothPlayersConnected() bool {
+	if len(game.GetPlayers()) < 2 {
+		return false
+	}
+
+	return game.players[0].hasWebsocketConnection() && game.players[1].hasWebsocketConnection()
+}
+
 func (game *Game) killGame() {
 	log.Println("Game should be killed")
 }
@@ -173,21 +181,22 @@ func (game Game) notifyPlayersAboutGameStart() error {
 		return err
 	}
 
-	game.GetPlayer1().writeMessage(colorDeterminedPlayer1)
+	game.GetPlayer1().writeMessage(string(colorDeterminedPlayer1))
 	game.GetPlayer1().SendBoardState(types.Move{}, game.board.PGN(), types.White)
 
-	game.GetPlayer2().writeMessage(colorDeterminedPlayer2)
+	game.GetPlayer2().writeMessage(string(colorDeterminedPlayer2))
 	game.GetPlayer2().SendBoardState(types.Move{}, game.board.PGN(), types.White)
 	return nil
 }
 
 func (game Game) broadcastMove(move types.Move) error {
-	err := game.GetPlayer1().SendBoardState(move, game.board.PGN(), game.currentTurnPlayer.color)
+	log.Println("broadcast move")
+	err := game.GetPlayer1().SendBoardState(move, game.board.PGN(), game.currentTurnPlayer.GetColor())
 	if err != nil {
 		return err
 	}
 
-	err = game.GetPlayer2().SendBoardState(move, game.board.PGN(), game.currentTurnPlayer.color)
+	err = game.GetPlayer2().SendBoardState(move, game.board.PGN(), game.currentTurnPlayer.GetColor())
 	if err != nil {
 		return err
 	}
@@ -212,5 +221,9 @@ func (game *Game) playerDisconnected(p *Player) {
 }
 
 func (game *Game) SetWebsocketConnectionFor(ctx context.Context, p *Player, ws *gorillaws.Conn) {
-	p.SetWebsocketConnectionAndSendBoardState(ctx, ws, game.board.PGN(), game.board.colorToMove)
+	p.SetWebsocketConnectionAndSendBoardState(ctx, ws, &game.board)
+}
+
+func (game *Game) SendBoardStateTo(p *Player) {
+	p.SendBoardState(game.board.getLastMove(), game.board.PGN(), game.board.colorToMove)
 }

chess/player.go

@@ -36,16 +36,25 @@ func (p Player) hasWebsocketConnection() bool {
 
 func (p *Player) SetWebsocketConnection(ctx context.Context, ws *gorillaws.Conn) {
 	p.Conn.SetWebsocketConnection(ws)
+	p.Conn.SetForColor(p.color)
 }
 
 func (p *Player) SetWebsocketConnectionAndSendBoardState(
 	ctx context.Context,
 	ws *gorillaws.Conn,
-	boardPosition string,
+	board *Board,
-	turnColor types.ChessColor,
 ) {
 	p.SetWebsocketConnection(ctx, ws)
-	p.SendBoardState(types.Move{}, boardPosition, turnColor)
+	p.SendBoardState(board.getLastMove(), board.PGN(), board.colorToMove)
+}
+
+func (p *Player) SetColor(color types.ChessColor) {
+	p.color = color
+	p.Conn.SetForColor(p.color)
+}
+
+func (p *Player) GetColor() types.ChessColor {
+	return p.color
 }
 
 func (p *Player) SetDisconnectCallback(cb func(*Player)) {
@@ -63,8 +72,8 @@ func (p *Player) IsInGame() bool {
 }
 
 func (p *Player) SendBoardState(move types.Move, boardPosition string, turnColor types.ChessColor) error {
-	var pColor = p.color
+	var pColor = p.GetColor()
-	if p.color == "" { // we default to white if we do not know the color yet
+	if p.GetColor() == "" { // we default to white if we do not know the color yet
 		pColor = types.White
 	}
 
@@ -80,11 +89,8 @@ func (p *Player) SendBoardState(move types.Move, boardPosition string, turnColor
 		return err
 	}
 
-	err = p.writeMessage(messageToSend)
+	p.writeMessage(string(messageToSend))
-	if err != nil {
+
-		log.Println("Error during message writing:", err)
-		return err
-	}
 	return nil
 }
 
@@ -99,11 +105,8 @@ func (p *Player) SendMoveAndPosition(move types.Move, boardPosition string) erro
 		return err
 	}
 
-	err = p.writeMessage(messageToSend)
+	p.writeMessage(string(messageToSend))
-	if err != nil {
+
-		log.Println("Error during message writing:", err)
-		return err
-	}
 	return nil
 }
 
@@ -117,26 +120,20 @@ func (p *Player) SendGameEnded(reason GameEndedReason) error {
 		log.Println("Error while marshalling: ", err)
 		return err
 	}
-	err = p.writeMessage(messageToSend)
+	p.writeMessage(string(messageToSend))
-	if err != nil {
+
-		log.Println("Error during message writing:", err)
-		return err
-	}
 	return nil
 }
 
-func (p *Player) writeMessage(msg []byte) error {
+func (p *Player) writeMessage(msg string) {
-	return p.Conn.Write(msg)
+	p.Conn.Write(msg)
 }
 
 func (p *Player) ReadMove() (types.Move, error) {
-	receivedMessage, err := p.readMessage()
+	receivedMessage := p.readMessage()
-	if err != nil {
-		return types.Move{}, err
-	}
 
 	var msg api.WebsocketMessage
-	err = json.Unmarshal(receivedMessage, &msg)
+	err := json.Unmarshal(receivedMessage, &msg)
 	if err != nil {
 		return types.Move{}, err
 	}
@@ -148,13 +145,9 @@ func (p *Player) ReadMove() (types.Move, error) {
 	return *msg.Move, nil
 }
 
-func (p *Player) readMessage() ([]byte, error) {
+func (p *Player) readMessage() []byte {
-	msg, err := p.Conn.Read()
+	msg := p.Conn.Read()
-	log.Printf("Reading message: %s from player %s", string(msg), p.Uuid.String())
+	log.Printf("Reading message from %s: %s", p.color.String(), string(msg))
 
-	return msg, err
+	return msg
-}
-
-func (p Player) GetPlayerColor() string {
-	return string(p.color)
 }

connection/message_buffer.go

@@ -50,7 +50,7 @@ func (b *MessageBuffer) Insert(msg string) {
 	b.cond.Broadcast()
 }
 
-func (b *MessageBuffer) Get() (string, error) {
+func (b *MessageBuffer) Get() string {
 	b.cond.L.Lock()
 	defer b.cond.L.Unlock()
 
@@ -69,7 +69,7 @@ func (b *MessageBuffer) Get() (string, error) {
 	}
 	b.getIndex = b.incrementAndWrapIndex(b.getIndex)
 
-	return msg.content, nil
+	return msg.content
 }
 
 func (b MessageBuffer) incrementAndWrapIndex(index int) int {

connection/message_buffer_test.go

@@ -66,8 +66,7 @@ func Test_MessageBuffer_GetWaitsForFirstData(t *testing.T) {
 		buf.Insert("delayed-message")
 	}()
 
-	msg, err := buf.Get()
+	msg := buf.Get()
-	assert.NoError(t, err)
 
 	endTime := time.Now()
 
@@ -79,8 +78,7 @@ func Test_MessageBuffer_GetWaitsForNewData(t *testing.T) {
 	buf := newMessageBuffer(2)
 
 	buf.Insert("message-1")
-	msg, err := buf.Get()
+	msg := buf.Get()
-	assert.NoError(t, err)
 	assert.Equal(t, "message-1", msg)
 
 	go func() {
@@ -89,8 +87,7 @@ func Test_MessageBuffer_GetWaitsForNewData(t *testing.T) {
 		buf.Insert("delayed-message")
 	}()
 
-	msg, err = buf.Get()
+	msg = buf.Get()
-	assert.NoError(t, err)
 	assert.Equal(t, "delayed-message", msg)
 }
 
@@ -117,8 +114,7 @@ func Test_MessageBuffer_IndexesAreCorrectAfterOverwritingOldData(t *testing.T) {
 		},
 		buf.messages)
 
-	msg, err := buf.Get()
+	msg := buf.Get()
-	assert.NoError(t, err)
 	assert.Equal(t, "message-2", msg)
 }
 
@@ -126,13 +122,11 @@ func Test_MessageBuffer_GetWaitsForNewDataIfOldOneWasAlreadyGotten(t *testing.T)
 	buf := newMessageBuffer(2)
 
 	buf.Insert(message1)
-	msg, err := buf.Get()
+	msg := buf.Get()
-	assert.NoError(t, err)
 	assert.Equal(t, message1, msg)
 
 	buf.Insert(message2)
-	msg, err = buf.Get()
+	msg = buf.Get()
-	assert.NoError(t, err)
 	assert.Equal(t, message2, msg)
 
 	go func() {
@@ -140,8 +134,7 @@ func Test_MessageBuffer_GetWaitsForNewDataIfOldOneWasAlreadyGotten(t *testing.T)
 		buf.Insert(message3)
 	}()
 
-	msg, err = buf.Get()
+	msg = buf.Get()
-	assert.NoError(t, err)
 	assert.Equal(t, message3, msg)
 
 }
@@ -157,9 +150,8 @@ func Test_MessageBuffer_InsertCatchesUpWithRead(t *testing.T) {
 	buf.Insert(message6)
 	buf.Insert(message7)
 
-	msg, err := buf.Get()
+	msg := buf.Get()
 
-	assert.NoError(t, err)
 	assert.Equal(t, message3, msg)
 }
 
@@ -172,7 +164,7 @@ func Test_MessageBuffer_FuckShitUp(t *testing.T) {
 	var readMsg = make([]string, 0)
 	go func() {
 		for i := 0; i < size*10; i++ {
-			msg, _ := buf.Get()
+			msg := buf.Get()
 			if msg == "99" {
 				break
 			}

connection/type.go

@@ -3,24 +3,38 @@ package connection
 import (
 	"context"
 	"log"
+	"mchess_server/types"
 	"sync"
 
+	"github.com/google/uuid"
 	gorillaws "github.com/gorilla/websocket"
 )
 
 type Connection struct {
+	ID                 uuid.UUID
 	ws                 *gorillaws.Conn
-	wsConnectionEstablished chan bool
-	wsWriteLock             sync.Mutex
 	ctx                context.Context
-	buffer                  MessageBuffer
+	rxBuffer           *MessageBuffer
+	txBuffer           *MessageBuffer
 	disconnectCallback func()
+	forColor           types.ChessColor
+
+	/* this is a hack since a user using the same
+	browser might get the same object of type Connection in two instances of
+	the same browser. Then if  Close() gets called for both of these instances
+	the first Close() will set ws=nil, and the seconds one will dereference this
+	nil pointer. The correct way to fix this, is to make sure, two instances
+	of the same browser do not get the same connection instance.
+	At the moment, the usage of localStorage 'identifies' an already connected
+	player and reuses the old Connection struct instance */
+	closingMutex sync.Mutex
 }
 
 func NewConnection(options ...func(*Connection)) *Connection {
 	connection := Connection{
-		buffer:                  *newMessageBuffer(100),
+		ID:       uuid.New(),
-		wsConnectionEstablished: make(chan bool),
+		rxBuffer: newMessageBuffer(100),
+		txBuffer: newMessageBuffer(100),
 	}
 
 	for _, option := range options {
@@ -50,6 +64,10 @@ func WithDisconnectCallback(cb func()) func(*Connection) {
 	}
 }
 
+func (conn *Connection) SetForColor(color types.ChessColor) {
+	conn.forColor = color
+}
+
 func (conn *Connection) SetDisconnectCallback(cb func()) {
 	conn.disconnectCallback = cb
 }
@@ -58,57 +76,81 @@ func (conn *Connection) HasWebsocketConnection() bool {
 	return conn.ws != nil
 }
 
+func (conn *Connection) readFromRxBuffer() {
+	for {
+		_, msg, err := conn.ws.ReadMessage()
+		if err != nil {
+			conn.logConnection("while reading from websocket: %w", "ERROR:", err.Error())
+			conn.Close("")
+			return
+		}
+		conn.rxBuffer.Insert(string(msg))
+	}
+}
+
+func (conn *Connection) writeTxBuffer() {
+	for {
+		msg := conn.txBuffer.Get()
+
+		if conn.ws == nil {
+			return
+		}
+
+		err := conn.ws.WriteMessage(gorillaws.TextMessage, []byte(msg))
+		if err != nil {
+			conn.logConnection("while writing to websocket: %w", "ERROR:", err.Error())
+			return
+		}
+	}
+}
+
 func (conn *Connection) SetWebsocketConnection(ws *gorillaws.Conn) {
 	if ws == nil {
+		conn.logConnection("ERROR: setting ws = null")
 		return
 	}
 
 	conn.ws = ws
 
-	select {
+	go conn.readFromRxBuffer()
-	case conn.wsConnectionEstablished <- true:
+	go conn.writeTxBuffer()
-	default:
+
+	defer conn.logConnection("websocket connection set")
 }
 
-	go func() {
+func (conn *Connection) Write(msg string) {
-		for {
+	conn.logConnection("Writing message: ", string(msg))
-			_, msg, err := conn.ws.ReadMessage()
+	conn.txBuffer.Insert(msg)
-			if err != nil {
-				log.Println("while reading from websocket: %w", err)
-				if conn.disconnectCallback != nil {
-					conn.disconnectCallback()
-				}
-				return
-			}
-			conn.buffer.Insert(string(msg))
-		}
-	}()
 }
 
-func (conn *Connection) Write(msg []byte) error {
+func (conn *Connection) Read() []byte {
-	conn.wsWriteLock.Lock()
+	msg := conn.rxBuffer.Get()
-	defer conn.wsWriteLock.Unlock()
 
-	if conn.ws == nil { //if ws is not yet set, we wait for it
+	return []byte(msg)
-		<-conn.wsConnectionEstablished
-	}
-
-	log.Printf("Writing message: %s", string(msg))
-	return conn.ws.WriteMessage(gorillaws.TextMessage, msg)
-}
-
-func (conn *Connection) Read() ([]byte, error) {
-	msg, err := conn.buffer.Get()
-	if err != nil {
-		conn.ws = nil
-		return nil, err // TODO: Tell game-handler that connection was lost
-	}
-
-	return []byte(msg), err
 }
 
 func (conn *Connection) Close(msg string) {
+	/* This is a hack, do not try this at home.
+	See more details at the definition of Connection */
+	conn.closingMutex.Lock()
+	defer conn.closingMutex.Unlock()
+
+	if conn == nil || conn.ws == nil {
+		return
+	}
+
+	conn.logConnection("closing websocket connection")
 	conn.ws.WriteMessage(gorillaws.TextMessage, []byte(msg))
 	conn.ws.Close()
 	conn.ws = nil
+	conn.txBuffer.Insert("we do this to make txBuffer.Get() return")
+}
+
+func (con *Connection) logConnection(v ...string) {
+	a := ""
+
+	for _, s := range v {
+		a += s + ", "
+	}
+	log.Println(a, "on connection ", con.ID, ", for color ", con.forColor.String())
 }

go.mod

@@ -5,27 +5,27 @@ go 1.22
 require (
 	github.com/gin-gonic/gin v1.10.0
 	github.com/google/uuid v1.6.0
-	github.com/samber/lo v1.39.0
+	github.com/samber/lo v1.41.0
 	github.com/stretchr/testify v1.9.0
 )
 
-require github.com/benbjohnson/clock v1.3.0 // indirect
+require github.com/benbjohnson/clock v1.3.5 // indirect
 
 require (
-	github.com/bytedance/sonic v1.11.6 // indirect
+	github.com/bytedance/sonic v1.11.9 // indirect
 	github.com/bytedance/sonic/loader v0.1.1 // indirect
 	github.com/cloudwego/base64x v0.1.4 // indirect
 	github.com/cloudwego/iasm v0.2.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/gabriel-vasile/mimetype v1.4.3 // indirect
+	github.com/gabriel-vasile/mimetype v1.4.4 // indirect
 	github.com/gin-contrib/sse v0.1.0 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
-	github.com/go-playground/validator/v10 v10.20.0 // indirect
+	github.com/go-playground/validator/v10 v10.22.0 // indirect
-	github.com/goccy/go-json v0.10.2 // indirect
+	github.com/goccy/go-json v0.10.3 // indirect
-	github.com/gorilla/websocket v1.5.1
+	github.com/gorilla/websocket v1.5.3
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/klauspost/cpuid/v2 v2.2.7 // indirect
+	github.com/klauspost/cpuid/v2 v2.2.8 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
@@ -36,11 +36,11 @@ require (
 	github.com/ugorji/go/codec v1.2.12 // indirect
 	go.uber.org/ratelimit v0.3.1
 	golang.org/x/arch v0.8.0 // indirect
-	golang.org/x/crypto v0.23.0 // indirect
+	golang.org/x/crypto v0.24.0 // indirect
-	golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 // indirect
+	golang.org/x/exp v0.0.0-20240613232115-7f521ea00fb8 // indirect
-	golang.org/x/net v0.25.0 // indirect
+	golang.org/x/net v0.26.0 // indirect
-	golang.org/x/sys v0.20.0 // indirect
+	golang.org/x/sys v0.21.0 // indirect
-	golang.org/x/text v0.15.0 // indirect
+	golang.org/x/text v0.16.0 // indirect
-	google.golang.org/protobuf v1.34.1 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,7 +1,9 @@
-github.com/benbjohnson/clock v1.3.0 h1:ip6w0uFQkncKQ979AypyG0ER7mqUSBdKLOgAle/AT8A=
+github.com/benbjohnson/clock v1.3.5 h1:VvXlSJBzZpA/zum6Sj74hxwYI2DIxRWuNIoXAzHZz5o=
-github.com/benbjohnson/clock v1.3.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
+github.com/benbjohnson/clock v1.3.5/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
 github.com/bytedance/sonic v1.11.6 h1:oUp34TzMlL+OY1OUWxHqsdkgC/Zfc85zGqw9siXjrc0=
 github.com/bytedance/sonic v1.11.6/go.mod h1:LysEHSvpvDySVdC2f87zGWf6CIKJcAvqab1ZaiQtds4=
+github.com/bytedance/sonic v1.11.9 h1:LFHENlIY/SLzDWverzdOvgMztTxcfcF+cqNsz9pK5zg=
+github.com/bytedance/sonic v1.11.9/go.mod h1:LysEHSvpvDySVdC2f87zGWf6CIKJcAvqab1ZaiQtds4=
 github.com/bytedance/sonic/loader v0.1.1 h1:c+e5Pt1k/cy5wMveRDyk2X4B9hF4g7an8N3zCYjJFNM=
 github.com/bytedance/sonic/loader v0.1.1/go.mod h1:ncP89zfokxS5LZrJxl5z0UJcsk4M4yY2JpfqGeCtNLU=
 github.com/cloudwego/base64x v0.1.4 h1:jwCgWpFanWmN8xoIUHa2rtzmkd5J2plF/dnLS6Xd/0Y=
@@ -13,6 +15,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gabriel-vasile/mimetype v1.4.3 h1:in2uUcidCuFcDKtdcBxlR0rJ1+fsokWf+uqxgUFjbI0=
 github.com/gabriel-vasile/mimetype v1.4.3/go.mod h1:d8uq/6HKRL6CGdk+aubisF/M5GcPfT7nKyLpA0lbSSk=
+github.com/gabriel-vasile/mimetype v1.4.4 h1:QjV6pZ7/XZ7ryI2KuyeEDE8wnh7fHP9YnQy+R0LnH8I=
+github.com/gabriel-vasile/mimetype v1.4.4/go.mod h1:JwLei5XPtWdGiMFB5Pjle1oEeoSeEuJfJE+TtfvdB/s=
 github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE=
 github.com/gin-contrib/sse v0.1.0/go.mod h1:RHrZQHXnP2xjPF+u1gW/2HnVO7nvIa9PG3Gm+fLHvGI=
 github.com/gin-gonic/gin v1.10.0 h1:nTuyha1TYqgedzytsKYqna+DfLos46nTv2ygFy86HFU=
@@ -25,8 +29,10 @@ github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJn
 github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
 github.com/go-playground/validator/v10 v10.20.0 h1:K9ISHbSaI0lyB2eWMPJo+kOS/FBExVwjEviJTixqxL8=
 github.com/go-playground/validator/v10 v10.20.0/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
-github.com/goccy/go-json v0.10.2 h1:CrxCmQqYDkv1z7lO7Wbh2HN93uovUHgrECaO5ZrCXAU=
+github.com/go-playground/validator/v10 v10.22.0 h1:k6HsTZ0sTnROkhS//R0O+55JgM8C4Bx7ia+JlgcnOao=
-github.com/goccy/go-json v0.10.2/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I=
+github.com/go-playground/validator/v10 v10.22.0/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
+github.com/goccy/go-json v0.10.3 h1:KZ5WoDbxAIgm2HNbYckL0se1fHD6rz5j4ywS6ebzDqA=
+github.com/goccy/go-json v0.10.3/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
@@ -34,11 +40,15 @@ github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/websocket v1.5.1 h1:gmztn0JnHVt9JZquRuzLw3g4wouNVzKL15iLr/zn/QY=
 github.com/gorilla/websocket v1.5.1/go.mod h1:x3kM2JMyaluk02fnUJpQuwD2dCS5NDG2ZHL0uE0tcaY=
+github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
+github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
 github.com/klauspost/cpuid/v2 v2.2.7 h1:ZWSB3igEs+d0qvnxR/ZBzXVmxkgt8DdzP6m9pfuVLDM=
 github.com/klauspost/cpuid/v2 v2.2.7/go.mod h1:Lcz8mBdAVJIBVzewtcLocK12l3Y+JytZYpaMropDUws=
+github.com/klauspost/cpuid/v2 v2.2.8 h1:+StwCXwm9PdpiEkPyzBXIy+M9KUb4ODm0Zarf1kS5BM=
+github.com/klauspost/cpuid/v2 v2.2.8/go.mod h1:Lcz8mBdAVJIBVzewtcLocK12l3Y+JytZYpaMropDUws=
 github.com/knz/go-libedit v1.10.1/go.mod h1:MZTVkCWyz0oBc7JOWP3wNAzd002ZbM/5hgShxwh4x8M=
 github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
 github.com/leodido/go-urn v1.4.0/go.mod h1:bvxc+MVxLKB4z00jd1z+Dvzr47oO32F/QSNjSBOlFxI=
@@ -55,6 +65,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/samber/lo v1.39.0 h1:4gTz1wUhNYLhFSKl6O+8peW0v2F4BCY034GRpU9WnuA=
 github.com/samber/lo v1.39.0/go.mod h1:+m/ZKRl6ClXCE2Lgf3MsQlWfh4bn1bz6CXEOxnEXnEA=
+github.com/samber/lo v1.41.0 h1:vZEqVQNmX/ykONfla8tiW6cdoLZxb3+LCZ63B8z/2eE=
+github.com/samber/lo v1.41.0/go.mod h1:w7R6fO7h2lrnx/s0bWcZ55vXJI89p5UPM6+kyDL373E=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
@@ -71,6 +83,8 @@ github.com/twitchyliquid64/golang-asm v0.15.1 h1:SU5vSMR7hnwNxj24w34ZyCi/FmDZTkS
 github.com/twitchyliquid64/golang-asm v0.15.1/go.mod h1:a1lVb/DtPvCB8fslRZhAngC2+aY1QWCk3Cedj/Gdt08=
 github.com/ugorji/go/codec v1.2.12 h1:9LC83zGrHhuUA9l16C9AHXAqEV/2wBQ4nkvumAE65EE=
 github.com/ugorji/go/codec v1.2.12/go.mod h1:UNopzCgEMSXjBc6AOMqYvWC1ktqTAfzJZUZgYf6w6lg=
+go.uber.org/atomic v1.7.0 h1:ADUqmZGgLDDfbSL9ZmPxKTybcoEYHgpYfELNoN+7hsw=
+go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/ratelimit v0.3.1 h1:K4qVE+byfv/B3tC+4nYWP7v/6SimcO7HzHekoMNBma0=
 go.uber.org/ratelimit v0.3.1/go.mod h1:6euWsTB6U/Nb3X++xEUXA8ciPJvr19Q/0h1+oDcJhRk=
 golang.org/x/arch v0.0.0-20210923205945-b76863e36670/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
@@ -78,18 +92,30 @@ golang.org/x/arch v0.8.0 h1:3wRIsP3pM4yUptoR96otTUOXI367OS0+c9eeRi9doIc=
 golang.org/x/arch v0.8.0/go.mod h1:FEVrYAQjsQXMVJ1nsMoVVXPZg6p2JE2mx8psSWTDQys=
 golang.org/x/crypto v0.23.0 h1:dIJU/v2J8Mdglj/8rJ6UUOM3Zc9zLZxVZwwxMooUSAI=
 golang.org/x/crypto v0.23.0/go.mod h1:CKFgDieR+mRhux2Lsu27y0fO304Db0wZe70UKqHu0v8=
+golang.org/x/crypto v0.24.0 h1:mnl8DM0o513X8fdIkmyFE/5hTYxbwYOjDS/+rK6qpRI=
+golang.org/x/crypto v0.24.0/go.mod h1:Z1PMYSOR5nyMcyAVAIQSKCDwalqy85Aqn1x3Ws4L5DM=
 golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 h1:vr/HnozRka3pE4EsMEg1lgkXJkTFJCVUX+S/ZT6wYzM=
 golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842/go.mod h1:XtvwrStGgqGPLc4cjQfWqZHG1YFdYs6swckp8vpsjnc=
+golang.org/x/exp v0.0.0-20240613232115-7f521ea00fb8 h1:yixxcjnhBmY0nkL253HFVIm0JsFHwrHdT3Yh6szTnfY=
+golang.org/x/exp v0.0.0-20240613232115-7f521ea00fb8/go.mod h1:jj3sYF3dwk5D+ghuXyeI3r5MFf+NT2An6/9dOA95KSI=
 golang.org/x/net v0.25.0 h1:d/OCCoBEUq33pjydKrGQhw7IlUPI2Oylr+8qLx49kac=
 golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
+golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
+golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
+golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.15.0 h1:h1V/4gjBv8v9cjcR6+AR5+/cIYK5N/WAgiv4xlsEtAk=
 golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
+golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
+golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
 google.golang.org/protobuf v1.34.1 h1:9ddQBjfCyZPOHPUiPxpYESBLc+T8P3E+Vo4IbKZgFWg=
 google.golang.org/protobuf v1.34.1/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

lobbies/lobby.go

@@ -10,7 +10,6 @@ import (
 type Lobby struct {
 	Uuid       uuid.UUID
 	Game       *chess.Game
-	PlayerJoined chan bool
 	Passphrase utils.Passphrase
 }
 
@@ -18,7 +17,6 @@ func NewEmptyLobbyWithUUID(uuid uuid.UUID) *Lobby {
 	return &Lobby{
 		Uuid: uuid,
 		Game: chess.NewGame(),
-		PlayerJoined: make(chan bool),
 	}
 }
 
@@ -31,12 +29,16 @@ func newEmptyLobbyWithPassphrase() *Lobby {
 
 func (l *Lobby) AddPlayerAndStartGameIfFull(player *chess.Player) {
 	l.Game.AddPlayersToGame(player)
-	if l.IsFull() {
+	if l.ContainsTwoPlayers() {
 		l.Game.StartHandling()
 	}
 }
 
-func (w *Lobby) IsFull() bool {
+func (w *Lobby) AreBothPlayersConnected() bool {
+	return w.Game.AreBothPlayersConnected()
+}
+
+func (w *Lobby) ContainsTwoPlayers() bool {
 	return len(w.Game.GetPlayers()) == 2
 }
 

lobbies/registry.go

@@ -7,7 +7,7 @@ import (
 )
 
 type LobbyRegistry struct {
-	lobbies map[uuid.UUID]*Lobby
+	lobbies map[utils.Passphrase]*Lobby
 }
 
 var instance *LobbyRegistry
@@ -21,7 +21,7 @@ func GetLobbyRegistry() *LobbyRegistry {
 }
 
 func newLobbyRegistry() *LobbyRegistry {
-	return &LobbyRegistry{lobbies: make(map[uuid.UUID]*Lobby)}
+	return &LobbyRegistry{lobbies: make(map[utils.Passphrase]*Lobby)}
 }
 
 func (r *LobbyRegistry) CreateNewPrivateLobby() *Lobby {
@@ -32,7 +32,7 @@ func (r *LobbyRegistry) CreateNewPrivateLobby() *Lobby {
 
 func (r *LobbyRegistry) GetLobbyForPlayer() *Lobby {
 	for _, lobby := range r.lobbies {
-		if !lobby.IsFull() {
+		if !lobby.ContainsTwoPlayers() {
 			return lobby
 		}
 	}
@@ -42,10 +42,6 @@ func (r *LobbyRegistry) GetLobbyForPlayer() *Lobby {
 	return newLobby
 }
 
-func (r *LobbyRegistry) GetLobbyByUUID(uuid uuid.UUID) *Lobby {
-	return r.lobbies[uuid]
-}
-
 func (r *LobbyRegistry) GetLobbyByPassphrase(p utils.Passphrase) *Lobby {
 	for _, lobby := range r.lobbies {
 		if lobby.Passphrase == p {
@@ -56,6 +52,6 @@ func (r *LobbyRegistry) GetLobbyByPassphrase(p utils.Passphrase) *Lobby {
 }
 
 func (r *LobbyRegistry) addNewLobby(lobby *Lobby) uuid.UUID {
-	r.lobbies[lobby.Uuid] = lobby
+	r.lobbies[lobby.Passphrase] = lobby
 	return lobby.Uuid
 }

lobbies/usher.go

@@ -3,8 +3,6 @@ package lobbies
 import (
 	"mchess_server/chess"
 	"mchess_server/utils"
-
-	"github.com/google/uuid"
 )
 
 type Usher struct {
@@ -24,25 +22,15 @@ func GetUsher() *Usher {
 }
 
 func (u *Usher) WelcomeNewPlayer(player *chess.Player) *Lobby {
-	lobby := GetLobbyRegistry().GetLobbyForPlayer()
+	return GetLobbyRegistry().GetLobbyForPlayer()
-	return lobby
 }
 
 func (u *Usher) CreateNewPrivateLobby(player *chess.Player) *Lobby {
-	lobby := GetLobbyRegistry().CreateNewPrivateLobby()
+	return GetLobbyRegistry().CreateNewPrivateLobby()
-	return lobby
 }
 
 func (u *Usher) FindExistingPrivateLobby(p utils.Passphrase) *Lobby {
-	lobby := GetLobbyRegistry().GetLobbyByPassphrase(p)
+	return GetLobbyRegistry().GetLobbyByPassphrase(p)
-	if lobby == nil || lobby.IsFull() {
-		return nil
-	}
-	return lobby
-}
-
-func (*Usher) GetLobbyByID(id uuid.UUID) *Lobby {
-	return GetLobbyRegistry().GetLobbyByUUID(id)
 }
 
 func (u *Usher) AddPlayerToLobbyAndStartGameIfFull(player *chess.Player, lobby *Lobby) {

main.go

@@ -13,6 +13,7 @@ var cert_file = cert_path + "fullchain.pem"
 var key_file = cert_path + "privkey.pem"
 
 func main() {
+	log.SetFlags(log.LstdFlags | log.Lmicroseconds)
 	var debugMode bool
 
 	debugModeLong := flag.Bool("debug", false, "activates debug mode")

types/common.go

@@ -16,6 +16,10 @@ func (c ChessColor) Opposite() ChessColor {
 	}
 }
 
+func (c ChessColor) String() string {
+	return string(c)
+}
+
 type AdditionalState struct {
 	BlackKingMoved  bool
 	WhiteKingMoved  bool