Written in Ruby for the command line.
- Description
- Installation
- How to Play
- Features
- Reflections and Personal Lessons
- Potential Improvements
- Acknowledgement
- Contact
This is a 2-player chess game that runs in the command line. Players take turns to move their pieces until there's a checkmate or stalemate, or until a player resigns mid game.
The more convenient way to run this program is by visiting this Replit page and clicking the run button to start the game.
If you want to run it locally though, you can clone the repo, go to the
project's root directory using cd chess_cli/ and run these commands;
You should have Ruby version 2.7 (and above) installed to run this program properly, though, 2.5 might work fine.
bundle install to install the project's dependencies and then
ruby lib/main.rb to run the program.
run rspec to run all tests or,
rspec spec/bishop_spec.rb (or any other spec file) to run just the tests in the file
If you need a refresher on the rules of chess, here's a quick guide with illustrations.
Players move pieces using algebraic
notation. It's a
really effecient method once you get the hang of it. All the squares have
positions from a1 to h8 (a to h and 1 to 8). So, a2a4 means "move the piece at square 'a2' to square 'a4'." Guides have been included on the sides of the board to help you remember.
During gameplay, you can enter save to save your progress. This save can be
loaded at the start of the program.
As shown above, you can load from any of 5 saves and you'll resume right where you left.
Instead of entering your move, you can enter quit to surrender and end the
game. There's also an option at the end of each match to immediatly play another round.
There are prompts throughout the game to guide you to the right output. If you tried to make an invalid move, there's a prompt to notify you. If you try to move your opponent's piece, there's a specific prompt telling you. There're also prompts to tell you when you have't selected a piece or when you try to make a move that places or leaves your king in check.
These colors help players to more easily recognise when it's their turn to make moves. The white player has the lighter background color to their name.
Checkmate and Stalemate have been implemented, so the game will display a prompt and then end when the conditions are met. The there's also a prompt whenever a king is in check, so this should serve as a fallback should the player forget to announce check.
According to the rules of chess, pawns that get to the other side must be promoted to either a Queen (this is called Queening), or Rook, Knight, or Bishop (this is referred to as Underpromotion). The same rule is enforced in this Game as well.
Pawns that have not yet moved in the game can make double moves.
I remember being very scared at the start of this project, cos I wasn't sure how I would implement many features. Even displaying the colorful board in the terminal seemed impossible. But I learnt that by just starting with the easiest tasks, all the others will into place gradually. As someone I know said, Chess should not be seen as one gigantic project, but as a combination of many small projects.
I had the opportunity to use 24 bit ANSI colors for the first time, a self-registering factory design pattern for creating the pieces, inheritance on a large scale, and many other small things I hadn't put to use before.
I'd like to add the option of selecting any piece and seeing all it's possible moves show up on the board. It'll look clunky for sure, but my hope is that it'll serve as training wheels for people newer to chess until they feel more confident about where every piece can go.
I want to make it so that you can't save multiple instances of the same match. Once a save file is loaded, it'll be deleted and the players will have the option to save again if they wish to return to it.
Right now, you have to be two players to enjoy the game, but it'd be fun to be able to play against the computer.
I ommited these features mostly because of a time constraint. Not many beginners seek out these moves, but anyone who has taken chess seriously in the past will expect to be able to make, at least, one of these moves, so I'll try to add them in the future.
Right now, all the core mechanisms of the piece movement, win and draw states, pawn promotion, and several others are well covered, as I've written about 200 unit tests. But the Game class which brings everything together and determines the game flow and user interaction is poorly tested. While I don't know how to write more integration type tests, there are still message expectation tests that I can make, so I'll try to cover as much as I reasonably can with unit tests.
Right now, I only use FEN strings to set up the board for tests (more on that in the acknowledgments), but I would like to let players start their own games from FEN. I'll likely wait to have the other special moves first since FEN holds valuable information about them.
I want to thank The Odin Project for providing me with the resources to learn most of what I know about actual programming. I wouldn't have had anything to do with the beautiful Ruby language if it wasn't for them. Their Discord community has also provided me with the much needed support in my coding journey thus far.
This project is the final project in their pure Ruby course. It's supposed to be a culmination of everything I've learned about Ruby until now and I must say, I feel a lot more competent as a developer after having built chess.
By using Lichess's Board Editor, I was able to easily set up chess scenarios, grab the FEN string for said scenaraio, and import into my game to recreate the board and set test expectations. My game may not look it, but it can load up any FEN string internally, and arrange the board accordingly.
Please feel free to reach out if you have any questions or suggestions.
Thanks for reading.