tetris/test/tetris_test.exs

defmodule TetrisTest do
  use ExUnit.Case
  import Tetris
  alias Tetris.{Brick}

  test "try to move right, success" do
    brick = Brick.new(%{location: {5,1}})
    bottom = %{}

    expected = brick |> Brick.right
    actual = try_right(brick, bottom)

    assert actual == expected
  end

  test "try to move right, failure returns original brick " do
    brick = Brick.new(%{location: {8,1}})
    bottom = %{}

    actual = try_right(brick, bottom)

    assert actual == brick
  end

  test "drops without merging" do
    brick = Brick.new(%{location: {5,5}})
    bottom = %{}

    expected = %{
      brick: Brick.down(brick),
      bottom: %{},
      score: 1,
      game_over: false
    }

    actual = drop(brick, bottom, :red)

    assert actual == expected
  end

  test "drops and merges" do
    brick = Brick.new(%{location: {5,16}})
    bottom = %{}

    %{score: score, bottom: actual_bottom} =
      Tetris.drop(brick, bottom, :red)

    assert Map.get(actual_bottom, {7,20}) ==  {7,20, :red}
    assert score == 0
  end

  test "drops and merges with collapse" do
    brick = Brick.new(%{location: {5,16}})
    bottom =
      for x <- 1..10,  y <- 17..20, x != 7 do
        {{x,y}, {x,y, :red}}
      end
      |> Map.new


    %{score: score, bottom: actual_bottom} =
      Tetris.drop(brick, bottom, :red)

    assert actual_bottom == %{}
    assert score == 1600
  end



end