Feature/imutable state

lib/scorched_earth/event_runner.rb

@@ -15,17 +15,17 @@ def subscribe(klass, &block)
       subscribers << [klass, block]
     end
 
-    def run(event)
-      subscribers.each do |klass, block|
-        block.call event if event.is_a? klass
-      end
+    def run(state, event)
+      subscribers
+        .select        { |klass, block| event.is_a? klass }
+        .inject(state) { |state, (klass, block)| block.call state, event }
     end
 
-    def process!
+    def process!(state)
       processing = Array.new(queue.size) { queue.pop }
 
-      processing.each do |event|
-        run event
+      processing.inject(state) do |state, event|
+        run state, event
       end
     end
   end

lib/scorched_earth/game.rb

@@ -51,11 +51,11 @@ def setup
 
     def update(delta)
       event_runner.publish Events::GameUpdate.new delta
-      event_runner.process!
+      event_runner.process! nil
     end
 
     def render(graphics)
-      event_runner.run Events::GameRender.new graphics
+      event_runner.run nil, Events::GameRender.new(graphics)
     end
 
     def publish(event)

lib/scorched_earth/subscribers/game_over/timeout.rb

@@ -6,7 +6,7 @@ module Timeout
       def setup
         super
 
-        event_runner.subscribe(Events::GameOver) do |event|
+        event_runner.subscribe(Events::GameOver) do |state, event|
           event.time < Time.now ? setup : event_runner.publish(event)
         end
       end

lib/scorched_earth/subscribers/game_render.rb

@@ -1,10 +1,12 @@
 module ScorchedEarth
   module Subscribers
     module GameRender
+
+
       def setup
         super
 
-        event_runner.subscribe(Events::GameRender) do |event|
+        event_runner.subscribe(Events::GameRender) do |state, event|
           graphics = event.graphics
 
           graphics.set_color color_palette.get('sky')

lib/scorched_earth/subscribers/game_update/collisions.rb

@@ -4,7 +4,7 @@ module Collisions
       def setup
         super
 
-        event_runner.subscribe(Events::GameUpdate) do
+        event_runner.subscribe(Events::GameUpdate) do |state, event|
           objects
             .select   { |object| object.is_a? Shot }
             .select   { |object| array.fetch(object.x, 0) > object.y }

lib/scorched_earth/subscribers/game_update/delta.rb

@@ -4,7 +4,7 @@ module Delta
       def setup
         super
 
-        event_runner.subscribe(Events::GameUpdate) do |event|
+        event_runner.subscribe(Events::GameUpdate) do |state, event|
           @objects = objects.map { |object| object.update event.delta }.compact
         end
       end

lib/scorched_earth/subscribers/hit/deform.rb

@@ -6,7 +6,7 @@ module Deform
       def setup
         super
 
-        event_runner.subscribe(Events::Hit) do |event|
+        event_runner.subscribe(Events::Hit) do |state, event|
           if event.object.x < array.size && event.object.x > 0
             @array = Services::Deform.new(array).call(event.object.x, event.radius)
             @players = players.map { |player| Player.new player.x, array[player.x] }

lib/scorched_earth/subscribers/hit/effect.rb

@@ -6,7 +6,7 @@ module Effect
       def setup
         super
 
-        event_runner.subscribe(Events::Hit) do |event|
+        event_runner.subscribe(Events::Hit) do |state, event|
           objects << Explosion.new(event.object.x, event.object.y)
         end
       end

lib/scorched_earth/subscribers/hit/radius.rb

@@ -6,7 +6,7 @@ module Radius
       def setup
         super
 
-        event_runner.subscribe(Events::Hit) do |event|
+        event_runner.subscribe(Events::Hit) do |state, event|
           if players.any? { |player| inside_radius? event.object.x - player.x, 0, event.radius }
             event_runner.publish Events::GameOver.new(Time.now + 0.25)
           end

lib/scorched_earth/subscribers/mouse_moved.rb

@@ -4,7 +4,7 @@ module MouseMoved
       def setup
         super
 
-        event_runner.subscribe(Events::MouseMoved) do |event|
+        event_runner.subscribe(Events::MouseMoved) do |state, event|
           @mouse = Mouse.new event.x, event.y, mouse.pressed_at
         end
       end

lib/scorched_earth/subscribers/mouse_pressed.rb

@@ -4,7 +4,7 @@ module MousePressed
       def setup
         super
 
-        event_runner.subscribe(Events::MousePressed) do |_event|
+        event_runner.subscribe(Events::MousePressed) do |state, event|
           @mouse = Mouse.new mouse.x, mouse.y, Time.now
         end
       end

lib/scorched_earth/subscribers/mouse_released/fire.rb

@@ -4,7 +4,7 @@ module Fire
       def setup
         super
 
-        event_runner.subscribe(Events::MouseReleased) do |_event|
+        event_runner.subscribe(Events::MouseReleased) do |state, event|
           if mouse.pressed_at && mouse.x && mouse.y
             shot = Shot.new current_player.x, array[current_player.x], velocity_x, velocity_y
 

lib/scorched_earth/subscribers/mouse_released/next_player.rb

@@ -4,7 +4,7 @@ module NextPlayer
       def setup
         super
 
-        event_runner.subscribe(Events::MouseReleased) do |_event|
+        event_runner.subscribe(Events::MouseReleased) do |state, event|
           @players = players.rotate!
         end
       end

test/event_runner_test.rb

@@ -0,0 +1,18 @@
+require 'test_helper'
+
+describe ScorchedEarth::EventRunner do
+  let(:runner) { ScorchedEarth::EventRunner.new }
+  let(:event)  { TestEvent }
+
+  describe "#run" do
+    specify "calls matching subscribers" do
+      yielded = []
+      func    = Proc.new { |e| yielded << e }
+
+      runner.subscribe event, &func
+      runner.run 42, event.new
+
+      assert_equal [42], yielded
+    end
+  end
+end

test/support/test_event.rb

@@ -0,0 +1 @@
+class TestEvent; end

test/test_helper.rb

@@ -3,5 +3,6 @@
 require 'bundler/setup'
 require 'support/simplecov'
 require 'support/null_object'
+require 'support/test_event'
 require 'scorched_earth'
 require 'minitest/autorun'