Add Elvish Archdruid

lib/magic/cards/elvish_archdruid.rb

@@ -0,0 +1,38 @@
+module Magic
+  module Cards
+    ElvishArchdruid = Creature("Elvish Archdruid") do
+      power 2
+      toughness 2
+      cost generic: 1, green: 2
+      creature_type "Elf Druid"
+
+      class PowerAndToughnessModification < Abilities::Static::PowerAndToughnessModification
+        def initialize(source:)
+          @source = source
+        end
+
+        def power
+          1
+        end
+
+        def toughness
+          1
+        end
+
+        def applicable_targets
+          source.controller.creatures.by_type("Elf") - [source]
+        end
+      end
+
+      class ManaAbility < Magic::TapManaAbility
+        def resolve!
+          source.controller.add_mana(green: source.controller.creatures.by_type("Elf").count)
+        end
+      end
+
+      def activated_abilities = [ManaAbility]
+
+      def static_abilities = [PowerAndToughnessModification]
+    end
+  end
+end

spec/cards/elvish_archdruid_spec.rb

@@ -0,0 +1,32 @@
+require 'spec_helper'
+
+RSpec.describe Magic::Cards::ElvishArchdruid do
+  include_context "two player game"
+
+  subject! { ResolvePermanent("Elvish Archdruid", owner: p1) }
+  let!(:lathril) { ResolvePermanent("Lathril, Blade Of The Elves", owner: p1) }
+
+  context "static ability" do
+    it "gives lathril +1/+1" do
+      expect(lathril.power).to eq(3)
+      expect(lathril.toughness).to eq(4)
+    end
+
+    it "does not give itself the boost" do
+      expect(subject.power).to eq(2)
+      expect(subject.toughness).to eq(2)
+    end
+  end
+
+  context "mana ability" do
+    def activate_ability
+      p1.activate_ability(ability: subject.activated_abilities.first)
+    end
+
+    it "adds green mana" do
+      activate_ability
+      # 1 mana from the Archdruid, 1 from Lathril
+      expect(p1.mana_pool[:green]).to eq(2)
+    end
+  end
+end