Minesweeper

Minesweeper game engine implemented in Ruby 2.x using OOP, TDD, CI and other cool techniques.

Introduction

This is my first Ruby project and its main purpose is to learn the language syntax, some of its best practices and how to apply CI techniques in this new environment.

The engine was implemented using TDD with TracisCI do run all test suites at every commit pushed to this remote.

To evaluate the tests coverage level and some aspects of code quality, this project uses Codacy to make code analysis and track the coverage level of each file. The coverage report is sent to Codacy by TravisCI at each successful build.

Engine interface

The game engine exposes a simple interface that allows the player to interact with the game while protects the mines positions information while the game isn' finished.

• Game creation

The game object is created using the Minesweeper class constructor:

game = Minesweeper.new(width, heigth, mines_number)

• Clicking on minefield cells

game.play(x, y)

Receives the x and y coordinates and clicks at the corresponding cell, then the cell becomes discovered. The method returns a boolean if it was a valid play. The play is valid if the cell isn't clicked and if it hasn't a flag. If the movement is valid and there is no mine in this cell and its neighbours, all its neighbours without bomb or flag become discovered and the same behaviour are applied to them.

• Flagging a cell

game.flag(x, y)

Puts a flag in a cell that wasn't clicked or remove the flag from it. Returns a boolean if the movement was valid.

• Check if game is finished

game.still_playing?

Returns true if the game is not finished. Returns false if the player clicked on a mine or all cells without mines are discovered.

• Check if player won

game.victory?

Return true if all cells without mines were discovered.

• Board State

game.board_state(xray: false)

Returns a representation of the minefield in the form of a two-dimensional array of PublicCell. For each cell in the field (PrivateCell) is created a corresponding PublicCell that contains only the information already discovered by the player. The user don't have access to all minefield cells information.

Passing the parameter xray=true when the game is finished returns a different board state. In this scenario, all cells become discovered, so the player can see all mines positions. Passing the parameter xray=true before the game is finished is not allowed and raises a SecurityError.

Demonstration

To show how this engine works, there's the file example.rb. You can run it using Ruby version 2.x to see a minefield with size 3x4 played randomly.