jhlywa/chess.js

Features

• Chess Board State Managers - Ships a headless chess board state manager that tracks piece placements and game conditions.
• Chess Game Engines - An engine that enforces official chess rules, generates legal moves, and tracks game state without a user interface.
• Stalemate Detectors - Reports whether the side to move has been stalemated.
• Threefold Repetition Detectors - Implements threefold repetition detection as a standard draw condition in chess.
• ASCII Board Renderers - Generates text-based visual representations of the board for debugging and display.
• Board State Queries - Ships multiple methods to query the board state in array, diagram, and FEN formats.
• Board State Manipulators - Provides utilities for manually altering piece placements and board configurations.
• Board Reset Utilities - Provides a function to reset the board to the standard starting position.
• Piece Placement Modifiers - Provides validated piece placement on individual squares for board setup.
• Piece Removal Utilities - Provides piece removal from individual squares for board manipulation.
• Castling Rights Managers - Provides configuration of castling rights for each color in the chess game.
• Check and Checkmate Detectors - Detects check and checkmate conditions for the side to move in the chess game.
• Chess Game Logic Engines - Implements detection of check, checkmate, stalemate, and draw conditions for chess analysis.
• Chess Move Validation Libraries - Verifies the legality of chess moves according to official game rules.
• Chess Notation Parsers - Parses and generates standard chess notations like FEN and PGN for game records.
• Game End State Detectors - Implements rule-based detection of draw conditions including the fifty-move rule and insufficient material.
• Game Notation Export - Load a board state from a FEN string or PGN notation, and export the current game as FEN or PGN.
• Legal Move Generators - Generates all legal chess moves by applying piece-specific patterns and filtering against check constraints.
• Move Execution Systems - Provides move execution systems that apply legal chess moves to the board state.
• Move History Stacks - Maintains a stack of move objects enabling undo of the last half-move to explore alternative variations.
• Move History Tracking - Records a chronological sequence of moves to enable state restoration and game review.
• Move Reversion Systems - Ships move reversion systems to undo game moves and restore previous board states.
• Move Validation Engines - Validates moves in Standard Algebraic Notation and executes them if legal.
• FEN Configuration Parsers - Encodes and decodes complete board configurations using Forsyth-Edwards Notation strings.
• FEN Managers - Initialize, load, or export board positions using Forsyth-Edwards Notation (FEN) strings, with optional validation skipping.
• PGN Notation Managers - Stores and retrieves move sequences and metadata using the Portable Game Notation format.
• Piece Position Querying - Provides utilities for retrieving piece locations and identifying which piece occupies a given square.
• Piece Placement Modifiers - Provides validated piece placement and removal on individual squares for board setup.
• Piece Placement Validators - Provides validated piece placement on squares, enforcing rules like preventing duplicate kings.
• Piece Removal Utilities - Provides piece removal from individual squares for board manipulation.
• Position Setup Utilities - Provides initialization of board positions from FEN strings and manual piece placement.
• Square Control Analyzers - Provides algorithms to determine which pieces attack or control specific squares on the board.
• Check and Checkmate Status Detectors - Reports check, checkmate, and stalemate status for the current player.
• Stalemate and Repetition Detectors - Detects stalemate and threefold repetition, key draw conditions in chess.
• Board Array Representations - Provides a method to retrieve the board as a two-dimensional array for programmatic access.
• Board Reset Utilities - Provides a function to reset the board to the standard starting position.
• FEN Position Loaders - Set up the board from a FEN string, resetting castling rights, en passant square, and move counters.
• Board Notation Validation - Parse a Forsyth-Edwards Notation string and return whether the board setup is valid or list any errors found.
• Move Notation Parsing - Parses Standard Algebraic Notation and variants into structured move objects for execution.
• Stalemate Status Detectors - Returns whether the side to move has been stalemated.
• Board State Visualizers - Displays board configurations using text-based diagrams and standard notation.
• Board State Inspectors - Returns board state in multiple formats and detects check, checkmate, and draw conditions.
• Board State Inspectors - Retrieves pieces, square colors, castling rights, and 2D array representations of the board.
• Turn Managers - Manages which side moves next, enforcing turn-based play rules.
• Board Position Hashing - Generates unique 64-bit hashes for board positions to enable rapid comparison and repetition detection.
• Position Hashing - Computes unique 64-bit hashes for board positions to enable fast repetition detection and comparison.
• Type-Safe Game State Definitions - Uses TypeScript's type system to enforce chess-specific invariants like move structures and piece types.

Star history