ChessCore

Chess validation and move-generation engine in Javascript.

Installation

npm i -S chesscorejs

Creating a new game

To create a pristine new game of chess -

import { ChessCore } from 'chesscorejs'
const game = new ChessCore()
game.makeMove(startPosition, endPosition, true)

The created 'game' object will give you access to the board, and the status of the game. Saving a game means saving these two objects and loading them back as required. No history of moves or logs are saved as part the game, it will be the user's task to save a history of moves if needed.

Loading a previous game can be done via creation of a new game object with the parameters, or by directly setting the board and status properties on an existing object.

Understanding the game object.

board is a 2-D array representing each square on a chess-board consisting of horizontal rows and vertical columns represented numerically 0-7, starting at the left WHITE ROOK as (0,0). The elements of the array are chess pieces. Each square is either a piece or null.

piece object has two properties - color and type. Import & use the ENUMS EPieceColor and EPieceType to represent these two values. Pieces can be retrieved either directly from the board or by using the methods getPiece() or getPieceAt() on the game object.

status object gives information on the state of the game and is updated by the library after each move. It consists of the check-states of the Kings, castle-ability of Kings and Rooks, en-passant state of the pawns, and the general status of the game represented by isCheckmate or isStalemate. It also contains the information on whose turn it is - currentTurn property.

Playing

Make a move using the makeMove() method. The method takes in three parameters - startPosition, endPoition and enforceTurns. All positions are represented by an object with the properties row and col, corresponding to squares on the chess board. Performing a move updates the status and board, and returns any captured pieces from the move (if any, otherwise null).

A move will only be executed if it is a valid move. Invalid moves return false. Positions can be translated to Standard Chess Notation (A-H, 1-8) using the translatePosition() static method, but all inputs have to be in the format of the object type TPosition with row and col properties.

Validation & Moves Generation

Valid moves can be obtained by calling getMoves() method, which takes in the position of the piece intending to move as it's first argument. Optional arguments include allowSpecialMoves (allowing castling, en passant), preventCheck (shows valid moves that will not put own king under check immediately).

Misc

The library comes with static method to calculate final Elo rating for game - calculateElo().

If you are using the font CHEQ.ttf to represent the chess peices, you can use the static method pieceToSymbol() to get the font-based character equivalent of each chess piece.

That's all

This library is made for educational & non-commercial purpose only and may not adhere to all standards and protocols recommended by competitive/professional Chess organisations. It is used on https://chessroulette.app. You are free to use or modify it as you wish. No copyright infringement intended.