Sketching a simple API for the game of Chess able to:

• enable the user to move pieces on the chessboard
• check whether the move is legal
• deal with possible illegal moves
• check whether a piece is taken

Focus on the interfaces to model the system and the implementation for the rules associated to one of the pieces and for the chessboard.

Software is designed on 3 key classes: Game, Chessboard and Piece.

• Game handles all the features related to game setup and mechanics and answers to the requests from the API.
• Chessboard handle the status of the chessboard. Place all the piaces on their initial position and expose methods to move them around.
• Piece knows its position, its team and its status. Each subclass (Paws, Rook, Knight, Bishop, King and Queen) has a custom implementation of the method that evaluate if a move is legal.

The API expose 3 endpoint:

Moves a piece in a give position (if the move is legal). Takes 2 arguments:

• piece the label of the piece to move
• target the location where to move the piece (with standard notation)

curl -d "piece=WP1&target=A6" -X POST http://127.0.0.1:5000/move

Illegal moves aren't executed and an error message is returned containing details about why the move is illegal.

Checks if a move is legal or not. Takes 2 arguments:

• piece the label of the piece to move
• target the location where to move the piece (with standard notation)

If the move is not legal, details about why the move is illegal are returned from the API.

curl -X GET http://127.0.0.1:5000/is-legal?piece=WP1&target=A6

Checks if a piece is taken. Takes 1 argument:

• piece the label of the piece to move

curl -X GET http://127.0.0.1:5000/is-taken?piece=BK1

Restart the game by resetting the chessboard and the places

Draw the status of the chessboard with icons of pieces and their acronyms

Pieces are described by a label:

• W or B for the team
• K, Q, B, N, R and P (N is for kNight) for the pieces
• 1 to 8 to identify different pieces of the same type.

Examples:

• White King: WK1
• Black Queen: BQ1
• Last White Pawn: WP8
• Second Black Knight: BN2

Position use the standard notation with files (columns, from A to H) and ranks (rows, from 1 to 8). Chessboard space goes from A1 to H8.

The project is written using Python (target version is 2.7) and uses Flask to expose the APIs and pytest is used for testing.

To install required library use:

pip install -r requirements.txt

To run a development server with live reload use:

FLASK_DEBUG=1 FLASK_APP=api.py python -m flask run

To run tests use

python -m pytest tests

• https://en.wikipedia.org/wiki/Chess
• http://scacchi.qnet.it/manuale/regole.htm#Indice