Now we're correctly handling moves

lib/chess/board.ex

@@ -2,17 +2,19 @@ defmodule Chess.Board do
   @moduledoc false
 
   def transform(board) do
-    Enum.map(0..7, fn (rank) ->
+    Enum.map(0..7, fn rank ->
-      Enum.map(0..7, fn (file) ->
+      {rank,
+       Enum.map(0..7, fn file ->
+         {file,
           board
-        |> piece({file, rank})
+          |> piece({file, rank})}
-      end)
+       end)}
     end)
   end
 
   def search(board, %{"type" => type, "colour" => colour}) do
     board
-    |> Enum.filter(fn({_index, piece}) ->
+    |> Enum.filter(fn {_index, piece} ->
       match?(%{"type" => ^type, "colour" => ^colour}, piece)
     end)
     |> indexes_to_tuples
@@ -20,7 +22,7 @@ defmodule Chess.Board do
 
   def search(board, %{"colour" => colour}) do
     board
-    |> Enum.filter(fn({_index, piece}) ->
+    |> Enum.filter(fn {_index, piece} ->
       match?(%{"colour" => ^colour}, piece)
     end)
     |> indexes_to_tuples
@@ -31,8 +33,8 @@ defmodule Chess.Board do
   end
 
   def move_piece(board, %{
-    "from" => [from_file, from_rank],
+        from: {from_file, from_rank},
-    "to" => [to_file, to_rank]
+        to: {to_file, to_rank}
       }) do
     {piece, board} = Map.pop(board, to_index({from_file, from_rank}))
     {piece_captured, board} = Map.pop(board, to_index({to_file, to_rank}))
@@ -42,8 +44,8 @@ defmodule Chess.Board do
       if castling_move?(piece, from_file, to_file) do
         board
         |> castling_move(%{
-          "from" => [from_file, from_rank],
+          from: {from_file, from_rank},
-          "to" => [to_file, to_rank]
+          to: {to_file, to_rank}
         })
         |> Map.get(:board)
       else
@@ -55,25 +57,27 @@ defmodule Chess.Board do
       to: %{"file" => to_file, "rank" => to_rank},
       board: board,
       piece: piece,
-      piece_captured: piece_captured,
+      piece_captured: piece_captured
     }
   end
 
   def castling_move?(%{"type" => "king"}, 4, to_file) do
     to_file == 2 || to_file == 6
   end
+
   def castling_move?(_, _, _), do: false
 
-  def castling_move(board, %{"from" => [4, rank], "to" => [2, _rank]}) do
+  def castling_move(board, %{from: {4, rank}, to: {2, _rank}}) do
     move_piece(board, %{
-      "from" => [0, rank],
+      from: {0, rank},
-      "to" => [3, rank],
+      to: {3, rank}
     })
   end
-  def castling_move(board, %{"from" => [4, rank], "to" => [6, _rank]}) do
+
+  def castling_move(board, %{from: {4, rank}, to: {6, _rank}}) do
     move_piece(board, %{
-      "from" => [7, rank],
+      from: {7, rank},
-      "to" => [5, rank],
+      to: {5, rank}
     })
   end
 
@@ -87,7 +91,6 @@ defmodule Chess.Board do
       "5,7" => %{"type" => "bishop", "colour" => "black"},
       "6,7" => %{"type" => "knight", "colour" => "black"},
       "7,7" => %{"type" => "rook", "colour" => "black"},
-
       "0,6" => %{"type" => "pawn", "colour" => "black"},
       "1,6" => %{"type" => "pawn", "colour" => "black"},
       "2,6" => %{"type" => "pawn", "colour" => "black"},
@@ -96,7 +99,6 @@ defmodule Chess.Board do
       "5,6" => %{"type" => "pawn", "colour" => "black"},
       "6,6" => %{"type" => "pawn", "colour" => "black"},
       "7,6" => %{"type" => "pawn", "colour" => "black"},
-
       "0,1" => %{"type" => "pawn", "colour" => "white"},
       "1,1" => %{"type" => "pawn", "colour" => "white"},
       "2,1" => %{"type" => "pawn", "colour" => "white"},
@@ -105,7 +107,6 @@ defmodule Chess.Board do
       "5,1" => %{"type" => "pawn", "colour" => "white"},
       "6,1" => %{"type" => "pawn", "colour" => "white"},
       "7,1" => %{"type" => "pawn", "colour" => "white"},
-
       "0,0" => %{"type" => "rook", "colour" => "white"},
       "1,0" => %{"type" => "knight", "colour" => "white"},
       "2,0" => %{"type" => "bishop", "colour" => "white"},
@@ -123,13 +124,13 @@ defmodule Chess.Board do
 
   defp indexes_to_tuples(list) do
     list
-    |> Enum.map(fn({index, _piece}) -> index_to_tuple(index) end)
+    |> Enum.map(fn {index, _piece} -> index_to_tuple(index) end)
   end
 
   defp index_to_tuple(index) do
     index
     |> String.split(",")
-    |> Enum.map(&(String.to_integer(&1)))
+    |> Enum.map(&String.to_integer(&1))
-    |> List.to_tuple
+    |> List.to_tuple()
   end
 end

lib/chess/game_state.ex

@@ -14,11 +14,15 @@ defmodule Chess.GameState do
     cond do
       player_checkmated?(board, colour) ->
         "checkmate"
+
       player_stalemated?(board, colour) ->
         "stalemate"
+
       king_in_check?(board, colour) ->
         "check"
-      true -> nil
+
+      true ->
+        nil
     end
   end
 
@@ -36,7 +40,7 @@ defmodule Chess.GameState do
     king =
       board
       |> Board.search(%{"type" => "king", "colour" => colour})
-      |> List.first
+      |> List.first()
 
     if is_nil(king) do
       raise "There is no #{colour} king!"
@@ -49,7 +53,7 @@ defmodule Chess.GameState do
   def player_cannot_move?(board, colour) do
     board
     |> Board.search(%{"colour" => colour})
-    |> Enum.all?(fn({file, rank}) ->
+    |> Enum.all?(fn {file, rank} ->
       board
       |> piece_cannot_move?({file, rank})
     end)
@@ -62,9 +66,9 @@ defmodule Chess.GameState do
 
     board
     |> Moves.available({file, rank})
-    |> Enum.all?(fn({to_file, to_rank}) ->
+    |> Enum.all?(fn {to_file, to_rank} ->
       board
-      |> Board.move_piece(%{"from" => [file, rank], "to" => [to_file, to_rank]})
+      |> Board.move_piece(%{from: {file, rank}, to: {to_file, to_rank}})
       |> Map.get(:board)
       |> king_in_check?(piece["colour"])
     end)

lib/chess/moves.ex

@@ -19,10 +19,10 @@ defmodule Chess.Moves do
       game.board
       |> Board.move_piece(move_params)
 
-    Multi.new
+    Multi.new()
     |> Multi.update(:game, Game.move_changeset(game, params))
     |> Multi.insert(:move, Ecto.build_assoc(game, :moves, params))
-    |> Repo.transaction
+    |> Repo.transaction()
   end
 
   def available(board, {file, rank}, move_list \\ []) do
@@ -33,14 +33,19 @@ defmodule Chess.Moves do
     case piece do
       %{"type" => "pawn"} ->
         Pawn.moves(board, {file, rank})
+
       %{"type" => "rook"} ->
         Rook.moves(board, {file, rank})
+
       %{"type" => "bishop"} ->
         Bishop.moves(board, {file, rank})
+
       %{"type" => "knight"} ->
         Knight.moves(board, {file, rank})
+
       %{"type" => "king"} ->
         King.moves(board, {file, rank}, move_list)
+
       %{"type" => "queen"} ->
         Queen.moves(board, {file, rank})
     end

lib/chess/moves/pieces/king/castling.ex

@@ -18,12 +18,13 @@ defmodule Chess.Moves.Pieces.King.Castling do
       []
     end
   end
+
   def moves(_board, _piece, _move_list), do: []
 
   def _moves(board, _rank, colour, move_list) do
     board
     |> Board.search(%{"type" => "rook", "colour" => colour})
-    |> Enum.map(fn ({file, rank}) ->
+    |> Enum.map(fn {file, rank} ->
       case file do
         0 -> queen_side_move(board, rank, colour, move_list)
         7 -> king_side_move(board, rank, colour, move_list)
@@ -35,10 +36,13 @@ defmodule Chess.Moves.Pieces.King.Castling do
 
   defp king_has_moved?(move_list, colour) do
     move_list
-    |> Enum.any?(fn (move) ->
+    |> Enum.any?(fn move ->
-      match?(%Move{
+      match?(
+        %Move{
           piece: %{"type" => "king", "colour" => ^colour}
-      }, move)
+        },
+        move
+      )
     end)
   end
 
@@ -60,19 +64,22 @@ defmodule Chess.Moves.Pieces.King.Castling do
 
   defp rook_has_moved?(file, move_list, colour) do
     move_list
-    |> Enum.any?(fn (move) ->
+    |> Enum.any?(fn move ->
-      match?(%Move{
+      match?(
+        %Move{
           piece: %{"type" => "rook", "colour" => ^colour},
-        from: %{"file" => ^file},
+          from: %{"file" => ^file}
-      }, move)
+        },
+        move
+      )
     end)
   end
 
   defp queen_side_in_check?(board, rank, colour) do
     [{2, rank}, {3, rank}]
-    |> Enum.any?(fn ({to_file, to_rank}) ->
+    |> Enum.any?(fn {to_file, to_rank} ->
       board
-      |> Board.move_piece(%{"from" => [4, rank], "to" => [to_file, to_rank]})
+      |> Board.move_piece(%{from: {4, rank}, to: {to_file, to_rank}})
       |> Map.get(:board)
       |> GameState.king_in_check?(colour)
     end)
@@ -80,9 +87,9 @@ defmodule Chess.Moves.Pieces.King.Castling do
 
   defp king_side_in_check?(board, rank, colour) do
     [{5, rank}, {6, rank}]
-    |> Enum.any?(fn ({to_file, to_rank}) ->
+    |> Enum.any?(fn {to_file, to_rank} ->
       board
-      |> Board.move_piece(%{"from" => [4, rank], "to" => [to_file, to_rank]})
+      |> Board.move_piece(%{from: {4, rank}, to: {to_file, to_rank}})
       |> Map.get(:board)
       |> GameState.king_in_check?(colour)
     end)

lib/chess/store/game.ex

@@ -14,14 +14,14 @@ defmodule Chess.Store.Game do
   alias Chess.Store.User
 
   schema "games" do
-    field :board, :map, default: Board.default()
+    field(:board, :map, default: Board.default())
-    field :turn, :string, default: "white"
+    field(:turn, :string, default: "white")
-    field :state, :string
+    field(:state, :string)
 
-    belongs_to :user, User
+    belongs_to(:user, User)
-    belongs_to :opponent, User, references: :id
+    belongs_to(:opponent, User, references: :id)
 
-    has_many :moves, Move
+    has_many(:moves, Move)
 
     timestamps()
   end
@@ -55,15 +55,17 @@ defmodule Chess.Store.Game do
   end
 
   def for_user_id(user_id) do
-    from game in Game,
+    from(game in Game,
       where: game.user_id == ^user_id,
       or_where: game.opponent_id == ^user_id
+    )
   end
 
   def check_game_state(changeset) do
     changeset
     |> put_change(
-      :state, GameState.state(changeset.changes.board, changeset.changes.turn)
+      :state,
+      GameState.state(changeset.changes.board, changeset.changes.turn)
     )
   end
 
@@ -78,6 +80,7 @@ defmodule Chess.Store.Game do
       changeset
     end
   end
+
   def validate_king_in_check(changeset, _, _), do: changeset
 
   def ordered(query) do

lib/chess_web/channels/game_channel.ex

@@ -32,7 +32,7 @@ defmodule ChessWeb.GameChannel do
       board: Board.transform(game.board),
       turn: game.turn,
       state: game.state,
-      moves: MoveList.transform(game.moves),
+      moves: MoveList.transform(game.moves)
     }
 
     socket
@@ -57,6 +57,7 @@ defmodule ChessWeb.GameChannel do
         update_opponent(socket, game)
 
         {:noreply, socket}
+
       {:error, :game, changeset, _} ->
         {message, _} = changeset.errors[:board]
 
@@ -73,13 +74,18 @@ defmodule ChessWeb.GameChannel do
       socket.assigns.user_id
       |> Queries.game_with_moves(socket.assigns.game_id)
 
-    moves = Moves.available(game.board, {
+    moves =
+      Moves.available(
+        game.board,
+        {
           String.to_integer(file),
           String.to_integer(rank)
-    }, game.moves)
+        },
+        game.moves
+      )
 
     reply = %{
-      moves: Enum.map(moves, &(Tuple.to_list(&1)))
+      moves: Enum.map(moves, &Tuple.to_list(&1))
     }
 
     {:reply, {:ok, reply}, socket}
@@ -88,24 +94,26 @@ defmodule ChessWeb.GameChannel do
   def update_opponent(socket, game) do
     opponent_id =
       opponent(game, socket.assigns.user_id).id
-      |> Integer.to_string
+      |> Integer.to_string()
 
     send_update(socket)
 
     "game:#{game.id}"
-    |> Presence.list
+    |> Presence.list()
     |> case do
       %{^opponent_id => _} ->
         nil
+
       _ ->
         socket
         |> Emails.opponent_moved_email(game)
-        |> Mailer.deliver_later
+        |> Mailer.deliver_later()
     end
   end
 
   def track_presence(socket) do
-    {:ok, _} = Presence.track(socket, socket.assigns.user_id, %{
+    {:ok, _} =
+      Presence.track(socket, socket.assigns.user_id, %{
         user_id: socket.assigns.user_id,
         online_at: inspect(System.system_time(:second))
       })
@@ -116,8 +124,8 @@ defmodule ChessWeb.GameChannel do
 
   def convert_params(%{"from" => from, "to" => to}) do
     %{
-      "from" => Enum.map(from, &(String.to_integer(&1))),
+      "from" => Enum.map(from, &String.to_integer(&1)),
-      "to" => Enum.map(to, &(String.to_integer(&1))),
+      "to" => Enum.map(to, &String.to_integer(&1))
     }
   end
 
@@ -130,7 +138,7 @@ defmodule ChessWeb.GameChannel do
       board: Board.transform(game.board),
       turn: game.turn,
       state: game.state,
-      moves: MoveList.transform(game.moves),
+      moves: MoveList.transform(game.moves)
     }
 
     ChessWeb.Endpoint.broadcast("game:#{game.id}", "game:update", payload)

lib/chess_web/templates/game/board.html.leex

@@ -1,4 +1,4 @@
-<div class="board board--black-to-move board--player-is-<%= player_colour(@user, @game) %>">
+<div class="board board--<%= @game.turn %>-to-move board--player-is-<%= player_colour(@user, @game) %>">
   <div class="board__rank-labels">
     <div class="board__label">1</div>
     <div class="board__label">2</div>
@@ -22,14 +22,14 @@
   </div>
 
   <div class="board__body">
-    <%= for rank <- 0..7 do %>
+    <%= for {rank, row} <- @board do %>
       <div class="board__row">
-        <%= for file <- 0..7 do %>
+        <%= for {file, piece} <- row do %>
           <%= render ChessWeb.SquareView,
             "square.html",
             rank: rank,
             file: file,
-            piece: @game.board["#{file},#{rank}"],
+            piece: piece,
             selected: {file, rank} == @selected,
             available: {file, rank} in @available %>
         <% end %>

lib/chess_web/views/live/board_live.ex

@@ -5,6 +5,7 @@ defmodule ChessWeb.BoardLive do
   alias Chess.Store.Game
   alias Chess.Repo
   alias Chess.Board
+  alias Chess.Moves
 
   import Chess.Auth, only: [get_user!: 1]
 
@@ -19,11 +20,24 @@ defmodule ChessWeb.BoardLive do
       Game.for_user(user)
       |> Repo.get!(game_id)
 
-    {:ok, assign(socket, game: game, user: user, selected: nil, available: [])}
+    {:ok, assign(socket, default_assigns(game, user))}
   end
 
   def handle_event("click", %{"rank" => rank, "file" => file}, socket) do
-    {:noreply, socket |> handle_click(file, rank)}
+    {
+      :noreply,
+      socket |> handle_click(String.to_integer(file), String.to_integer(rank))
+    }
+  end
+
+  defp default_assigns(game, user) do
+    %{
+      board: Board.transform(game.board),
+      game: game,
+      user: user,
+      selected: nil,
+      available: []
+    }
   end
 
   defp handle_click(socket, file, rank) do
@@ -34,27 +48,56 @@ defmodule ChessWeb.BoardLive do
     colour = ChessWeb.GameView.player_colour(user, game)
 
     assigns =
+      if colour == game.turn do
         case socket.assigns do
-        %{:selected => nil} ->
+          %{selected: nil} ->
-          case Board.piece(board, {file, rank}) do
+            handle_selection(board, colour, file, rank)
-            %{"colour" => ^colour} ->
-              [{:selected, selected(file, rank)}]
 
           _ ->
-              []
+            handle_move(socket.assigns, file, rank)
         end
-
-        _ ->
-          [{:selected, nil}]
       end
 
     assign(socket, assigns)
   end
 
-  defp selected(file, rank) do
+  defp handle_selection(board, colour, file, rank) do
-    {
+    case Board.piece(board, {file, rank}) do
-      String.to_integer(file),
+      %{"colour" => ^colour} ->
-      String.to_integer(rank)
+        [
-    }
+          {:selected, {file, rank}},
+          {:available, Moves.available(board, {file, rank})}
+        ]
+
+      _ ->
+        []
+    end
+  end
+
+  defp handle_move(
+         %{game: game, available: available, selected: selected},
+         file,
+         rank
+       ) do
+    if {file, rank} in available do
+      new_game =
+        game
+        |> Moves.make_move(%{from: selected, to: {file, rank}})
+        |> case do
+          {:ok, %{game: new_game}} ->
+            new_game
+        end
+
+      new_board = Board.transform(new_game.board)
+
+      [
+        {:selected, nil},
+        {:available, []},
+        {:board, new_board},
+        {:game, new_game}
+      ]
+    else
+      [{:selected, nil}, {:available, []}]
+    end
   end
 end

test/chess/board_test.exs

@@ -6,35 +6,62 @@ defmodule Chess.BoardTest do
   alias Chess.Board
 
   test "returns a piece from the board" do
-    board = Board.default
+    board = Board.default()
 
     expected_piece = %{"type" => "pawn", "colour" => "white"}
     assert Board.piece(board, {4, 1}) == expected_piece
   end
 
   test "finds pieces on the board" do
-    board = Board.default
+    board = Board.default()
 
     piece = %{"type" => "pawn", "colour" => "white"}
+
     expected_result = [
-      {0, 1}, {1, 1}, {2, 1}, {3, 1}, {4, 1}, {5, 1}, {6, 1}, {7, 1},
+      {0, 1},
+      {1, 1},
+      {2, 1},
+      {3, 1},
+      {4, 1},
+      {5, 1},
+      {6, 1},
+      {7, 1}
     ]
+
     assert Board.search(board, piece) == expected_result
   end
 
   test "finds pieces on the board with a partial search" do
-    board = Board.default
+    board = Board.default()
 
     piece = %{"colour" => "white"}
-    expected_result = [
+
-      {0, 1}, {1, 1}, {2, 1}, {3, 1}, {4, 1}, {5, 1}, {6, 1}, {7, 1},
+    expected_result =
-      {0, 0}, {1, 0}, {2, 0}, {3, 0}, {4, 0}, {5, 0}, {6, 0}, {7, 0},
+      [
-    ] |> Enum.sort
+        {0, 1},
+        {1, 1},
+        {2, 1},
+        {3, 1},
+        {4, 1},
+        {5, 1},
+        {6, 1},
+        {7, 1},
+        {0, 0},
+        {1, 0},
+        {2, 0},
+        {3, 0},
+        {4, 0},
+        {5, 0},
+        {6, 0},
+        {7, 0}
+      ]
+      |> Enum.sort()
+
     assert Board.search(board, piece) == expected_result
   end
 
   test "finds a single piece on the board" do
-    board = Board.default
+    board = Board.default()
 
     piece = %{"type" => "king", "colour" => "black"}
     assert Board.search(board, piece) == [{4, 7}]
@@ -42,44 +69,41 @@ defmodule Chess.BoardTest do
 
   test "moves a piece" do
     board = %{
-      "3,0" => %{"type" => "queen", "colour" => "white"},
+      "3,0" => %{"type" => "queen", "colour" => "white"}
     }
 
-    %{board: new_board} =
+    %{board: new_board} = Board.move_piece(board, %{from: {3, 0}, to: {5, 2}})
-      Board.move_piece(board, %{"from" => [3, 0], "to" => [5, 2]})
 
     assert new_board == %{
-      "5,2" => %{"type" => "queen", "colour" => "white"},
+             "5,2" => %{"type" => "queen", "colour" => "white"}
            }
   end
 
   test "can perform a castling move on the kings side" do
     board = %{
       "4,0" => %{"type" => "king", "colour" => "white"},
-      "7,0" => %{"type" => "rook", "colour" => "white"},
+      "7,0" => %{"type" => "rook", "colour" => "white"}
     }
 
-    %{board: new_board} =
+    %{board: new_board} = Board.move_piece(board, %{from: {4, 0}, to: {6, 0}})
-      Board.move_piece(board, %{"from" => [4, 0], "to" => [6, 0]})
 
     assert new_board == %{
              "6,0" => %{"type" => "king", "colour" => "white"},
-      "5,0" => %{"type" => "rook", "colour" => "white"},
+             "5,0" => %{"type" => "rook", "colour" => "white"}
            }
   end
 
   test "can perform a castling move on the queens side" do
     board = %{
       "4,0" => %{"type" => "king", "colour" => "white"},
-      "0,0" => %{"type" => "rook", "colour" => "white"},
+      "0,0" => %{"type" => "rook", "colour" => "white"}
     }
 
-    %{board: new_board} =
+    %{board: new_board} = Board.move_piece(board, %{from: {4, 0}, to: {2, 0}})
-      Board.move_piece(board, %{"from" => [4, 0], "to" => [2, 0]})
 
     assert new_board == %{
              "2,0" => %{"type" => "king", "colour" => "white"},
-      "3,0" => %{"type" => "rook", "colour" => "white"},
+             "3,0" => %{"type" => "rook", "colour" => "white"}
            }
   end
 end

test/chess/store/game_test.exs

@@ -20,6 +20,7 @@ defmodule Chess.Store.GameTest do
         opponent_id: opponent.id,
         turn: "white"
       }
+
       changeset = Game.changeset(%Game{}, attrs)
 
       assert changeset.valid?
@@ -33,6 +34,7 @@ defmodule Chess.Store.GameTest do
         opponent_id: 2,
         turn: "white"
       }
+
       changeset = Game.changeset(%Game{}, attrs)
 
       assert changeset.valid?
@@ -81,15 +83,17 @@ defmodule Chess.Store.GameTest do
       user = insert(:user)
       opponent = insert(:opponent)
 
-      game = insert(:game, %{
+      game =
-        board: Board.default,
+        insert(:game, %{
+          board: Board.default(),
           user_id: user.id,
-        opponent_id: opponent.id,
+          opponent_id: opponent.id
         })
 
-      move_params = %{"from" => [4, 1], "to" => [4, 3]}
+      move_params = %{from: {4, 1}, to: {4, 3}}
 
-      changeset = Game.move_changeset(
+      changeset =
+        Game.move_changeset(
           game,
           Board.move_piece(game.board, move_params)
         )