attempted to write capture logic

app/controllers/games_controller.rb

@@ -1,5 +1,5 @@
 class GamesController < ApplicationController
-  before_action :authenticate_user!, only: %i[new create show]
+  before_action :authenticate_user!, only: %i[new create show update]
 
   def index
     @available_games = Game.available
@@ -17,6 +17,16 @@ def show
     @game = Game.find(params[:id])
   end
 
+  def update
+    @game = Game.find(params[:id])
+    if @game.user_black.nil?
+      @game.update(user_black_id: current_user.id)
+    else
+      @game.update(user_white_id: current_user.id)
+    end
+    redirect_to root_path
+  end
+
   def game_params
     params.require(:game).permit(:user_white_id, :user_black_id)
   end

app/models/game.rb

@@ -4,8 +4,6 @@ class Game < ApplicationRecord
   has_many :pieces
   scope :available, -> { where('user_white_id IS NULL OR user_black_id IS NULL') }
 
-  scope :available, -> { where('user_white_id IS NULL OR user_black_id IS NULL') }
-
   def populate_board!
     # this should create all 32 Pieces with their initial X/Y coordinates.
 

app/models/knight.rb

@@ -1 +1,2 @@
-class Knight < Piece; end
+class Knight < Piece
+end

app/models/piece.rb

@@ -1,6 +1,38 @@
 class Piece < ApplicationRecord
   belongs_to :game
+
+  def move_to!(new_x, new_y)
+    unless square_occupied?(new_x, new_y)
+      update_attributes(x_position: new_x, y_position: new_y)
+      return
+    end
+    occupying_piece = get_piece_at_coor(new_x, new_y)
+    unless (occupying_piece.is_white && is_white?) || (!occupying_piece.is_white && !is_white?)
+      capture_piece(occupying_piece)
+      update_attributes(x_position: new_x, y_position: new_y)
+      return
+    end
+    raise ArgumentError, 'That is an invalid move. Cannot capture your own piece.'
+  end
+
+  def square_occupied?(new_x, new_y)
+    piece = game.pieces.find_by(x_position: new_x, y_position: new_y)
+    return false if piece.nil?
+    true
+  end
+
+  def get_piece_at_coor(x, y)
+    Piece.all.find_each do |piece|
+      return piece if piece.x_position == x && piece.y_position == y
+    end
+    nil
+  end
+
+  def capture_piece(piece_captured)
+    piece_captured.update(x_position: nil, y_position: nil)
+  end
 end
+
 PAWN = 'Pawn'.freeze
 ROOK = 'Rook'.freeze
 KNIGHT = 'Knight'.freeze

app/views/games/index.html.erb

@@ -10,6 +10,7 @@
       <div class="col-12">
         <% if game.user_white == nil %>
           No one is playing White.
+          <%= link_to "Join game as white", game_path(game.id), method: :put, class: "btn btn-success"%>
         <% else %>
           <%= game.user_white.name %> is playing white. 
         <% end %>    
@@ -18,8 +19,9 @@
       <div class="col-12">
         <% if game.user_black == nil %>
           No one is playing Black.
+          <%= link_to "Join game as black", game_path(game.id), method: :put, class: "btn btn-success"%>
         <% else %>
-          <%= game.user_black.name %> is playing white.
+          <%= game.user_black.name %> is playing black.
         <% end %>    
       </div>
     </div>

config/routes.rb

@@ -2,5 +2,5 @@
   devise_for :users
   # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
   root 'games#index'
-  resources :games, only: %i[new create show]
+  resources :games, only: %i[new create show update]
 end

spec/controllers/pieces_controller_spec.rb

@@ -3,7 +3,7 @@
 RSpec.describe PiecesController, type: :controller do
   describe 'Test action' do
     it 'should successfully return true' do
-      expect(true).to eq true
+      expect(true).to eq(true)
     end
   end
 end

spec/models/piece_spec.rb

@@ -1,4 +1,75 @@
 require 'rails_helper'
 
 RSpec.describe Piece, type: :model do
+  describe 'square_occupied? method' do
+    it 'returns true if the square your piece is moving to is occupied by another piece' do
+      game1 = FactoryGirl.create(:game)
+      piece1 = Piece.create(game_id: game1.id, is_white: false, type: PAWN, x_position: 1, y_position: 2)
+      occupied = piece1.square_occupied?(piece1.x_position, piece1.y_position)
+      expect(occupied).to eq(true)
+    end
+    it 'returns false if the square your piece is moving to is not occupied' do
+      game1 = FactoryGirl.create(:game)
+      piece1 = Piece.create(game_id: game1.id, is_white: false, type: QUEEN, x_position: 1, y_position: 2)
+      occupied = piece1.square_occupied?(2, piece1.y_position)
+      expect(occupied).to eq(false)
+    end
+  end
+
+  describe 'get_piece_at_coor method' do
+    it 'returns the piece object at given square' do
+      game1 = FactoryGirl.create(:game)
+      piece1 = Piece.create(game_id: game1.id, is_white: false, type: PAWN, x_position: 1, y_position: 2)
+      piece_found = piece1.get_piece_at_coor(1, 2)
+      expect(piece_found).to eq(piece1)
+    end
+    it 'returns nil if there is no piece at specified square' do
+      game1 = FactoryGirl.create(:game)
+      piece1 = Piece.create(game_id: game1.id, is_white: false, type: KNIGHT, x_position: 7, y_position: 1)
+      piece_found = piece1.get_piece_at_coor(1, 1)
+      expect(piece_found).to eq(nil)
+    end
+  end
+
+  describe 'capture_piece method' do
+    it 'sets piece x and y coor to nil if piece can be captured' do
+      game1 = FactoryGirl.create(:game)
+      piece1 = Piece.create(game_id: game1.id, is_white: false, type: KNIGHT, x_position: 7, y_position: 1)
+      piece1.capture_piece(piece1)
+      expect(piece1.x_position).to eq(nil)
+      expect(piece1.y_position).to eq(nil)
+    end
+  end
+
+  describe 'move_to! method' do
+    it 'Changes x and y coor of moving piece to x and y of destination square if that square is empty' do
+      game1 = FactoryGirl.create(:game)
+      piece1 = Piece.create(game_id: game1.id, is_white: false, type: KING, x_position: 2, y_position: 4)
+      piece1.move_to!(3, 4)
+      expect(piece1.x_position).to eq(3)
+      expect(piece1.y_position).to eq(4)
+    end
+    it 'updates x and y of moving piece to new square and captures enemy piece at that square' do
+      game1 = FactoryGirl.create(:game)
+      black_king = Piece.create(game_id: game1.id, is_white: false, type: KING, x_position: 2, y_position: 4)
+      white_queen = Piece.create(game_id: game1.id, is_white: true, type: QUEEN, x_position: 1, y_position: 4)
+      black_king.move_to!(1, 4)
+      expect(black_king.x_position).to eq(1)
+      expect(black_king.y_position).to eq(4)
+      white_queen.reload
+      expect(white_queen.x_position).to eq(nil)
+      expect(white_queen.y_position).to eq(nil)
+    end
+    it 'raises argument error if player tries to capture or move into a friendly piece' do
+      game1 = FactoryGirl.create(:game)
+      black_pawn = game1.pieces.create(game_id: game1.id, is_white: false, type: PAWN, x_position: 2, y_position: 5)
+      black_knight = game1.pieces.create(game_id: game1.id, is_white: false, type: KNIGHT, x_position: 3, y_position: 6)
+      expect { black_pawn.move_to!(3, 6) }.to raise_error(ArgumentError)
+      black_knight.reload
+      expect(black_pawn.x_position).to eq(2)
+      expect(black_pawn.y_position).to eq(5)
+      expect(black_knight.x_position).to eq(3)
+      expect(black_knight.y_position).to eq(6)
+    end
+  end
 end