yd-chess-lib

Chess Lib

Chess Lib is a library that allows us emulate a game of chess.

Installation

npm install yd-chess-lib

Getting started with Chess Lib

Here is an example of a basic app using Chess Lib:

import { Chess } from "yd-chess-lib";

let chess = Chess.getInstance();

Public Methods

To access the library you have to call "getInstance()" in every call. We implement a Singleton, to avoid duplicating data.

getInstance

getInstance();

import { Chess } from "yd-chess-lib";

let chess = Chess.getInstance();

printChessboardToConsole

Print the chessboard in the console.

printChessboardToConsole = () => void;

import { Chess } from "yd-chess-lib";

let chess = Chess.getInstance();

//print chessboard
chess.printChessboardToConsole();

move

Moves the piece located in square from to square to. Only if it is a valid and allowed move. Return true if the move was made. Also can move and promote a pawn in one movement example: "7cx8bQ" || "2bx1cR" ("Q","R","N","B")

move = (from: String, to: string) => boolean; || move = (movement: string) => boolean;

import { Chess } from "yd-chess-lib";

let chess = Chess.getInstance();

// moving 2d => 4d
chess.move("2d", "4d"); //return true
chess.printChessboardToConsole();

// moving 2b => 3b
chess.move("2bx3b"); //return true
chess.printChessboardToConsole();

// moving 2c => 5c
chess.move("2cx5c"); //return false (invalid or not allowed movement)
chess.printChessboardToConsole();

// moving 3b => 8bQ
chess.move("3b", "4b"); //return true
chess.move("4bx5b"); //return true
chess.move("5bx6b"); //return true
chess.move("6bx7a"); //return true
chess.move("7ax8bQ"); //return true
chess.printChessboardToConsole();

Result

//moved 2d => 4d         //moved 2b => 3b         //invalid move           //Default 3b => 8bQ
RB|NB|BB|QB|KB|BB|NB|RB  RB|NB|BB|QB|KB|BB|NB|RB  RB|NB|BB|QB|KB|BB|NB|RB  RB|QW|BB|QB|KB|BB|NB|RB
PB|PB|PB|PB|PB|PB|PB|PB  PB|PB|PB|PB|PB|PB|PB|PB  PB|PB|PB|PB|PB|PB|PB|PB  60|PB|PB|PB|PB|PB|PB|PB
50|51|52|53|54|55|56|57  50|51|52|53|54|55|56|57  50|51|52|53|54|55|56|57  50|51|52|53|54|55|56|57
40|41|42|43|44|45|46|47  40|41|42|43|44|45|46|47  40|41|42|43|44|45|46|47  40|41|42|43|44|45|46|47
30|31|32|PW|34|35|36|37  30|31|32|PW|34|35|36|37  30|31|32|PW|34|35|36|37  30|31|32|PW|34|35|36|37
20|21|22|23|24|25|26|27  20|PW|22|23|24|25|26|27  20|PW|22|23|24|25|26|27  20|21|22|23|24|25|26|27
PW|PW|PW|13|PW|PW|PW|PW  PW|11|PW|13|PW|PW|PW|PW  PW|11|PW|13|PW|PW|PW|PW  PW|11|PW|13|PW|PW|PW|PW
RW|NW|BW|QW|KW|BW|NW|RW  RW|NW|BW|QW|KW|BW|NW|RW  RW|NW|BW|QW|KW|BW|NW|RW  RW|NW|BW|QW|KW|BW|NW|RW

getSquare

We get the piece by passing the position.

getSquare = (position: string) => boolean;

let chess = Chess.getInstance();
//pawn
let square_2_d = chess.getSquare("2d");
console.log(square_2_d);

Result

{ key: "2d", color: "W", type: "P", movementsAllowed: ["3d", "4d"], neverMoved: true }

let chess = Chess.getInstance();
//empty square
let square_5_c = chess.getSquare("fc");
console.log(square_5_c);

Result

null

getChessboard

We get the all chessboard.

getChessboard = () :
  Array<Array<{ key: string; color: string; type: string; movementsAllowed: Array<string>; neverMoved: boolean } | null>>;

let chess = Chess.getInstance();
let chessboard = chess.getChessboard();
console.log(chessboard);

Result

[
  [
    {
      key: '1a',
      color: 'W',
      type: 'R',
      movementsAllowed: [],
      neverMoved: true
    },
    {
      key: '1b',
      color: 'W',
      type: 'N',
      movementsAllowed: ["3c", "3a"],
      neverMoved: true
    },
    ...

getHistory

We get an arrays with all the movements made in order that were made.

getHistory = (): Array<string>;

let history = chess.getHistory();
console.log(history);

Result

["2dx4d", "2bx3b"]

isInCheckMate

This function return a boolean with value true is the color is in checkmate. Parameter color "W" (White) "B" (Black)

isInCheckMate = (color: Color): boolean;

chess.isInCheckMate("W"); // check if white is in checkmate
chess.isInCheckMate("B"); // check if black is in checkmate

replacePawn

This function allow us to replace the pawn if is in the end of the rows for a Queen(Q), Rook(R), Bishop(B) or Knight(N).

pawnPromotion = (pawn_key: string, type_of_piece: TypeOfPiece): void

chess.replacePawn("1b", "Q");
chess.replacePawn("8a", "N");

isDraw

This function evaluates if it’s a draw returns a string with the type of draw. if isn’t a draw return null. p_color is the color that it is turn to play

isDraw = (p_color: Color): string | null

chess.isDraw("W"); //   "Slatemate"
chess.isDraw("W"); //   "Dead Position"
chess.isDraw("B"); //   "Repetition"
chess.isDraw("W"); //   null

isCasteling

This function evaluates the board and return a boolean with the value true if it can castling.

isCasteling = (kingPosition: string, rookPosition: string): boolean

chess.isCasteling("1e", "1h"); //   true
chess.isCasteling("1e", "1h"); //   false (may does not meet all requirements)
chess.isCasteling("1e", "1b"); //   false

hasToPromoteAPawn

hasToPromoteAPawn return true if you have a replace a pawn.

hasToPromoteAPawn = (): boolean

chess.hasToPromoteAPawn(); //   true