How?

Rspec with DrugGame

Rules

Rules

• - 5 points
• - 7 points
• - 10 points
• - 15 points
• - 1000 points

Gosu

http://www.libgosu.org/

Gosu::Window

      require 'gosu'

      class GameWindow < Gosu::Window
        def initialize
        end

        def update
        end

        def draw
        end
      end

Initialize

class GameWindow < Gosu::Window
  def initialize
    super 640, 480, false
    self.caption = "DrugGame"
    @background_image =
      Gosu::Image.new(self, "media/Bg.png")
  end
end

Draw

  class GameWindow < Gosu::Window
    def draw
      @background_image.draw(0, 0, 0)
    end
  end

Player

  class Player
    def initialize(window)
      @image =
        Gosu::Image.new(window, "media/player.png")
      @x = @vel_x = @y = @vel_y = 0.0
    end

    def warp(x, y) ; @x, @y = x, y ; end

    def turn_left ; @vel_x -= 4.5 ; end

    def turn_right ; @vel_x += 4.5 ; end

    def move
      @x += @vel_x
      @vel_x *= 0.95
    end

    def draw
      @image.draw_rot(@x, @y, 1, 0)
    end
  end

Adding player to window

  class GameWindow < Gosu::Window
    def initialize
      ...
      @player = Player.new(self)
      @player.warp(500, 500)
    end

    def draw
      ...
      @player.draw
    end
  end

Keyboard

  class GameWindow < Gosu::Window
    def update
      if button_down? Gosu::KbLeft ||
        button_down? Gosu::GpLeft
        @player.turn_left
      end
      if button_down? Gosu::KbRight ||
        button_down? Gosu::GpRight
        @player.turn_right
      end
      @player.move
    end
  end

Gravity

  class Player
    def set_gravity
      @vy += 1
      if @vy > 0
        @vy.times do
          if would_fit(0, 1)
            @y += 1
          else
            @vy = 0
          end
        end
      end
      (-@vy).times { @y -= 1 } if @vy < 0
    end
  end

Jump

  class Player
    def jump
      @vy = -20 if @map.solid?(@x, @y, @height)
    end
  end

  class GameWindow < Gosu::Window
    def update
    ...
      if button_down?(Gosu::KbUp) ||
        button_down?(Gosu::GpButton0)
        @player.jump
      end
    end
  end

Distance

    def collect_awards(awards)
      awards.reject! do |award|
      if Gosu::distance(@x, @y, award.x, award.y) < 50
        @score += award.score
      else
        false
      end
    end

Camera

    def draw
      translate(-@camera_x, -@camera_y) do
        @player.draw
        @background_image.draw(0, -500, 0)
        @map.draw

        @awards.each { |award| award.draw }
        @monsters.each { |monster| monster.draw }
      end
      @font.draw("Score: #{@player.score}",
        10, 10, 2, 1.0, 1.0, 0xffffff00)
    end

Why?

• check your code
• help avoid crappy code

Rspec or TestUnit?

Describe and context

  describe DrugGame::GameWindow do

    context "monsters" do
    end

    context "awards" do
      context "score" do
      end
    end
  end

Example

  describe User do

    it "should have correct first name" do
      user = User.create(first_name: "John", last_name: "Rambo")
      user.first_name.should == "John"
    end

    it "should have correct last name" do
      user = User.create(first_name: "John", last_name: "Rambo")
      user.last_name.should == "Rambo"
    end

Matchers

  user.name.should eq("John")
  user.name.should == "John"
  user.age.should >= 18
  user.name.should match(/ohn/)
  user.adult.should be_true
  user.friends.should be_empty # empty?

Matchers

  def awesome?
    true
  end

  user.should be_awesome

Lambda

lambda do
    post :create, :user => { name: "John" }
end.should change(User, :count).by(1)

Example

  describe User do

    it "should have correct first name" do
      user = User.create(first_name: "John", last_name: "Rambo")
      user.first_name.should == "John"
    end

    it "should have correct last name" do
      user = User.create(first_name: "John", last_name: "Rambo")
      user.last_name.should == "Rambo"
    end

Let or Let!

  describe User do
    let(:user) { User.create(first_name: "John", last_name: "Rambo") }
    let!(current_user) { ... }

    it "should have correct first name" do
      user.first_name.should == "John"
    end

    it "should have correct last name" do
      user.last_name.should == "Rambo"
    end
  end

New syntax

  foo.should eq(bar)
  foo.should_not eq(bar)

  expect(foo).to eq(bar)
  expect(foo).not_to eq(bar)

New syntax

lambda do
    post :create, :user => { name: "John" }
end.should change(User, :count).by(1)

expect do
    post :create, :user => { name: "John" }
end.to change(User, :count).by(1)

stub

  Class Claim
    def send_to_ess
      SEND_TO_ESS!!!
    end

    def valid?
      send_to_ess
      return true
    end
  end

  claim.should be_valid

stub

  Class Claim
    def send_to_ess
      SEND_TO_ESS!!!
    end

    def valid?
      send_to_ess
      return true
    end
  end

  claim.stub(:send_to_ess).and_return(true)
  claim.should be_valid

mock

  Class User
    def find_friend
      find if age == 18
    end
  end

  user = double("User, age: 18, gender: male")
  user.should_receive(:find) { user }
  user.find_friend

How?

remove e-mail field

  it "should be valid when email empty" do
    @user = Category.create(name: "Chris", email: "bla@mailinator.com")
    @user.email = ""
    @user.save
    @user.email.should == ""
  end

  validates_presence_of :email

  it "should be valid when email empty" do
    @user = Category.create(name: "Chris", email: "bla@mailinator.com)
    @user.email = ""
    @user.save
    @user.email.should == ""
  end

  it "should be valid when email empty" do
    @user = Category.create(name: "Chris", email: "bla@mailinator.com)
    @user.email = ""
    @user.save
    @user.reload
    @user.email.should == ""
  end

Lets test our game

movable.rb

  def warp(x, y)
    @x, @y = x, y
  end

movable_spec.rb

  let(:movable) { DrugGame::Movable.new($window) }

  it "should set position" do
    movable.warp(40, 50)
    movable.x.should == 40
    movable.y.should == 50
  end

movable.rb

  def turn_left
    @vel_x = -5
  end

movable_spec.rb

  let(:movable) { DrugGame::Movable.new($window) }
  it "should turn left" do
    lambda {
      movable.turn_left
    }.should change(movable, :vel_x).by(-5)
  end

movable.rb

  def turn_right
    @vel_x = +5
  end

movable_spec.rb

  let(:movable) { DrugGame::Movable.new($window) }

  it "should turn right" do
    lambda {
      movable.turn_right
    }.should change(movable, :vel_x).by(5)
  end

game_window.rb

 def update
  @monsters.push(DrugGame::Monster.new(self)) if rand(1000) < 5 && @monsters.size < 25
  @monsters.each { |monster| monster.move }
  @awards.push(DrugGame::Award.new(self)) if rand(100) < 4 && @awards.size < 25
  @awards.each { |award| award.move }
  @player.move
  @player.collect_awards(@awards)
  @player.touch_monster(@monsters)
  @camera_x = [[@player.x - self.width/2, 0].max, @map.width - self.width].min
  @camera_y = -[[@height/2 - @player.y, 0].max, height/2].min
end

game_window.rb

  def update
    generate_monsters
    generate_awards
    set_player
    set_camera
  end

  def generate_monsters
    @monsters.push(DrugGame::Monster.new(self)) if rand(1000) < 5 && @monsters.size < 25
    @monsters.each { |monster| monster.move }
  end

game_window.rb

  context "monsters" do
    it "should not generate monster" do
      lambda {
        $window.stub(:rand).and_return(5)
        $window.generate_monsters
      }.should_not change($window.monsters, :length)
    end

    it "should generate monster" do
      lambda {
        $window.stub(:rand).and_return(3)
        $window.generate_monsters
      }.should change($window.monsters, :length).by(1)
    end
  end

validation

  it "should have valid name" do
    @user = User.create(name: "John")
    @user.name == ""
    @user.should_not be_valid
  end

Shoulda

  it { should belong_to(:user) }
  it { should have_many(:tags).through(:taggings) }
  it { should validate_uniqueness_of(:title) }
  it { should validate_uniqueness_of(:title).scoped_to(:user_id) }
  it { should validate_presence_of(:body).with_message(/wtf/) }
  it { should validate_presence_of(:title) }
  it { should validate_numericality_of(:user_id) }
  it { should delegate_method(:work).to(:robot) }

Q & A