ChessState

A chess game state manager that is intended to be variant friendly (eventually).

Download

npm install --save chessstate

Link to NPM page: https://www.npmjs.com/package/chessstate

Using ChessState

let ChessState = require("chessstate")

// Initalize a new game
let game = new ChessState.ChessState()  // Uses default config object

// Execute move "e4" for white.
game.move("e4")

// Execute move "e5" for black.
game.move("e5")

// Print out an ascii representation of the board.
game.printBoard()

Example of usage: https://github.com/NathanTan/ChessStateExample

Initalization

// Defaul config object
const config = {
  gameType: 0, // Standard Chess (Currently only type availible)
  fen: "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1", // Example FEN string of the starting position
  hideOutput: true // Will not output to the console
}

// Example config object
const config = {
  gameType: 0, // Standard Chess (Currently only type availible)
  fen: "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1", // Example FEN string of the boards position after the move "e4"
  hideOutput: true // Will not output to the console
}

Methods

move()

Executes a move.

Parameters:

• Move: a string representing a chess move. Acceptable forms of moves constist of PGN string, FEN string, or resigning with the string "resign".

Examples:

> game.move("e4") // Move the white pawn to "e4" as the first move of the game

> game.move("rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1") // Move the white pawn to "e4" as the first move of the game

> game.move("resign") // White resigns (Provided no player has moved yet)

getStatus()

Returns an object containing the status of the game.

Parameters: None

Example:

> game.getStatus()
{ gameOver: false, turn: null, winner: null }

Output

Standard Chess Grid:

               Black
  ---------------------------------
0 | r | n | b | q | k | b | n | r |
  ---------------------------------
1 | p | p | p | p | p | p | p | p |
  ---------------------------------
2 |   |   |   |   |   |   |   |   |
  ---------------------------------
3 |   |   |   |   |   |   |   |   |
  ---------------------------------
4 |   |   |   |   |   |   |   |   |
  ---------------------------------
5 |   |   |   |   |   |   |   |   |
  ---------------------------------
6 | P | P | P | P | P | P | P | P |
  ---------------------------------
7 | R | N | B | Q | K | B | N | R |
  ---------------------------------
    A   B   C   D   E   F   G   H
               White

Basic Chess Information

What is a FEN string?

A FEN string represents a standard chess board and includes information about the state of the game, including important details such as which player has the next turn, castling availability, En Passant, Halfmoves, and Fullmoves.

What is a PGN string?

A PGN string represents an individual chess move.

Supported Varients

Bughouse

Description:

Bughouse is a 4 player, 2v2 version of chess where 2 seperate games of chess happen simultaneously. But you and your teammate play opposite colors and when you capture a piece on your board, you pass it to your teammate where they can spend a turn placing it on their board.

Varient Usage

When placing a piece on the board that was captured by a teammate, add a tilda to the pgn. Example:

> game.move("e4~")

Use the function "getExtraPieces" to get the extra pieces a player has available to them. Example:

// Get the extra pieces for the first board that white can use
> game.getExtraPieces(0, StandardTurns.white)

Notes

This library has no dependencies.

Base repository location: https://github.com/NathanTan/ChessState