✨ feat: Creature Recruitment | Dwelling + slice: BuildDwelling -> DwellingBuilt

heroesofddd_rails_application/README.md

@@ -1,5 +1,19 @@
 # README
 
+## How to run?
+
+Install ruby on your machine and Rails:
+`gem install rails`
+
+0. `bundle install`
+1. `docker compose up`
+2. `rails db:create`
+3. `rails db:migrate`
+4. `rails server`
+
+Fixing format errors:
+`rubocop --auto-correct`
+
 This README would normally document whatever steps are necessary to get the
 application up and running.
 

heroesofddd_rails_application/lib/heroes/creature_recruitment/build_dwelling.rb

@@ -0,0 +1,6 @@
+module Heroes
+  module CreatureRecruitment
+    BuildDwelling = Data.define(:dwelling_id, :creature_id, :cost_per_troop)
+    DwellingBuilt = Data.define(:dwelling_id, :creature_id, :cost_per_troop)
+  end
+end

heroesofddd_rails_application/lib/heroes/creature_recruitment/configuration.rb

@@ -0,0 +1,7 @@
+module Heroes
+  module CreatureRecruitment
+    class Configuration
+      def call(event_store, command_bus) end
+    end
+  end
+end

heroesofddd_rails_application/lib/heroes/creature_recruitment/dwelling.rb

@@ -0,0 +1,41 @@
+module Heroes
+  module CreatureRecruitment
+    module Dwelling
+      NotBuilt = Data.define
+      Built = Data.define(:dwelling_id, :creature_id, :cost_per_troop, :available_creatures)
+
+      class << self
+        def decide(command, state)
+          case command
+          when BuildDwelling
+            build(command, state)
+          else
+            raise "Unknown command"
+          end
+        end
+
+        def evolve(state, event)
+          case event
+          when DwellingBuilt
+            Built.new(dwelling_id: event.dwelling_id, creature_id: event.creature_id, cost_per_troop: event.cost_per_troop, available_creatures: SharedKernel::Resources::Amount.of(0))
+          else
+            raise "Unknown event"
+          end
+        end
+
+        def initial_state
+          NotBuilt.new
+        end
+
+        private
+
+        def build(command, state)
+          if state.is_a?(Built)
+            return []
+          end
+          [ DwellingBuilt.new(dwelling_id: command.dwelling_id, creature_id: command.creature_id, cost_per_troop: command.cost_per_troop) ]
+        end
+      end
+    end
+  end
+end

heroesofddd_rails_application/lib/heroes/shared_kernel/resources.rb

@@ -0,0 +1,43 @@
+module Heroes
+  module SharedKernel
+    module Resources
+      Type = [ :GOLD, :WOOD, :ORE, :MERCURY, :SULFUR, :CRYSTAL, :GEMS ]
+
+      Amount = Data.define(:raw) do
+        def self.of(raw)
+          raise ArgumentError, "Amount cannot be negative" if raw < 0
+
+          new(raw)
+        end
+
+        def self.zero
+          new(0)
+        end
+
+        def <=>(other)
+          raw <=> other.raw
+        end
+
+        def +(other)
+          Amount.new(raw + other.raw)
+        end
+
+        def -(other)
+          Amount.new(raw - other.raw)
+        end
+      end
+
+      Cost = Data.define(:resources) do
+        def self.resources(*resources)
+          resource_map = resources.to_h { |type, amount| [ type, Amount.new(amount) ] }
+          new(resource_map)
+        end
+
+        def *(multiplier)
+          resource_map = resources.transform_values { |amount| Amount.new(amount.raw * multiplier) }
+          self.class.new(resource_map)
+        end
+      end
+    end
+  end
+end

heroesofddd_rails_application/test/lib/heroes/creature_recruitment/build_dwelling_test.rb

@@ -0,0 +1,55 @@
+require "minitest/autorun"
+require_relative "../../../../lib/heroes/creature_recruitment/build_dwelling"
+require_relative "../../../../lib/heroes/creature_recruitment/dwelling"
+require_relative "../../../../lib/heroes/shared_kernel/resources"
+
+
+module Heroes
+  module CreatureRecruitment
+    DECIDER = Heroes::CreatureRecruitment::Dwelling
+    class BuildDwellingTest < Minitest::Test
+      # givens
+      @dwelling_id = "portal_of_glory"
+      @creature_id = "angel"
+      @cost_per_troop = Heroes::SharedKernel::Resources::Cost.resources([ :GOLD, 3000 ], [ :CRYSTAL, 1 ])
+
+      def test_given_not_built_dwelling_when_build_dwelling_then_dwelling_built
+        # given
+        given_events = []
+
+        # when
+        command = Heroes::CreatureRecruitment::BuildDwelling.new(@dwelling_id, @creature_id, @cost_per_troop)
+        result = decide(given_events, command)
+
+        # then
+        expected_events = [ Heroes::CreatureRecruitment::DwellingBuilt.new(@dwelling_id, @creature_id, @cost_per_troop) ]
+        assert_equal(expected_events, result)
+      end
+
+      def test_given_built_dwelling_when_build_dwelling_then_nothing
+        # given
+        given_events = [
+          Heroes::CreatureRecruitment::DwellingBuilt.new(@dwelling_id, @creature_id, @cost_per_troop)
+        ]
+
+        # when
+        command = Heroes::CreatureRecruitment::BuildDwelling.new(@dwelling_id, @creature_id, @cost_per_troop)
+        result = decide(given_events, command)
+
+        # then
+        expected_events = []
+        assert_equal(expected_events, result)
+      end
+
+      private
+
+      def decide(given_events, command)
+        DECIDER.decide(command, state_from(given_events))
+      end
+
+      def state_from(events)
+        events.reduce(DECIDER.initial_state) { |state, event| DECIDER.evolve(state, event) }
+      end
+    end
+  end
+end