Chess

A command line game built with Ruby, tested with RSpec Live: https://replit.com/@supersakana/chess-1

About

Chess is a complex game. The biggest challenge while building this project was organizing the code in a clean modular way. My programming skills are not the same as before building chess. There are many things I would do differently if I were to recreate this project. Building chess was a learning experience for me. I got to see the value of TDD-ing complex features and solving problems using both tests and a debugger together. Thank you to The Odin Project for an amazing curriculum and for inspiring me to take on this project. If you the reader see areas that I can improve on, any feedback is appreciated. I'm always looking to improve my skills.

Full Project Description https://www.theodinproject.com/lessons/ruby-ruby-final-project

Reading this Program

Before jumping into the code, I think it would be useful to go over how this program is structured. When a Game is initialized, a new Board is created. This Board is a class that contains a hash of Cell objects. Depending on the position (@value) of the cell, a Piece would be created too. The entire Board object looks similar to this...

Board.cells
 {[0, 0] =>  (Cell Object)
             @bg_color=:light_black,
             @value=[0, 0]
             @piece= (Rook Object)
                     @color=:light_white,
                     @icon="♜",
                     @moved=false,
                     @value=5>,
   ...
   }

You can see that this hash is a key => value data structure. The key here is the location ([0, 0]) and the value is the Cell object with it's attributes (and a Piece object if included). This hash is composed of 64 cells representing each cell in an 8 x 8 chess board. I made the decission to organize these cells in a ruby hash because it would be easy traverse in finding legal moves, check, checkmate, stalemate, displaying the board UI, etc... there are many different ways to approach this project. This is just the implementation that worked best for me and my initial thought process.

Features

Main

Check: Alerts user if King is under attack
Capture: Removes foe piece if user legaly attacks
Grave: Stores and displays total value of captured pieces
Save/Load: User can save game at any time and resume
Exit: User can exit the game at any time
Replay: If game over, prompts user to play new game or exit

Game Over

Checkmate: User is in check and has no legal moves
Stalemate: User has no legal moves
Insufficient Material: Ends game if board contains...
- only kings
- only kings and one knight
- only kings and bishops with the same cell color

Special

Pawn Jumps: Pawns can jump 2 cells from initial position (without piece infront of it)
En Passant: Pawns can capture foe pawn if they jump next to user pawn on correct row
Promotion: If user pawn reaches the end of foe side, pawn can promote to Queen, Rook, Bishop, Knight
Castling: Kingside and Queenside

How to play

Repl: https://replit.com/@supersakana/chess-1

Copy/Paste in Terminal (must have ruby installed)

git@github.com:supersakana/chess.git
cd chess
ruby lib/main.rb

The initial program comes with 2 saved files, enter the file number to load or any other key for a new game

A new game will prompt the user to input names for Player 1 and 2

Enter a start and landing position (a2a3) to make a move

NOTE: This move gets converted into a key (a2a3 => [[0, 1], [0, 2]]) so the program can traverse through the cells/hash

Players can save s or exit e at any point in the game

The game will continue until a game over condition is met

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