strategy pattern

lib/generators/bad_news.rb

@@ -0,0 +1,13 @@
+module Newsletter
+  module Generators
+    class BadNews < Base
+      def header_content
+        'BAD'
+      end
+
+      def body_content
+        'NEWS'
+      end
+    end
+  end
+end

lib/generators/base.rb

@@ -1,20 +1,17 @@
 module Newsletter
   module Generators
     class Base
-      def render
-        <<~HTMLORMARKDOWN
-          #{header}
-
-          #{body}
-        HTMLORMARKDOWN
-      end
+      attr_reader :strategy
 
-      def header
-        raise NotImplementedError
+      def initialize(strategy:)
+        @strategy = strategy
       end
 
-      def body
-        raise NotImplementedError
+      def render
+        Newsletter::Strategies
+          .const_get(strategy)
+          .new(self)
+          .execute
       end
     end
   end

lib/generators/good_news.rb

@@ -0,0 +1,13 @@
+module Newsletter
+  module Generators
+    class GoodNews < Base
+      def header_content
+        'GOOD'
+      end
+
+      def body_content
+        'NEWS'
+      end
+    end
+  end
+end

lib/strategies/html.rb

@@ -0,0 +1,23 @@
+require 'forwardable'
+
+module Newsletter
+  module Strategies
+    class Html
+      extend Forwardable
+
+      def_delegators :@context, :header_content, :body_content
+
+      def initialize(context)
+        @context = context
+      end
+
+      def execute
+        <<~HTMLORMARKDOWN
+          <h1>#{header_content}</h1>
+
+          <p>#{body_content}</p>
+        HTMLORMARKDOWN
+      end
+    end
+  end
+end

lib/strategies/markdown.rb

@@ -0,0 +1,25 @@
+require 'forwardable'
+
+module Newsletter
+  module Strategies
+    class Markdown
+      extend Forwardable
+
+      def_delegators :@context, :header_content, :body_content
+
+      def initialize(context)
+        @context = context
+      end
+
+      def execute
+        <<~HTMLORMARKDOWN
+          **********
+          # #{header_content}
+          **********
+          #{body_content}
+          **********
+        HTMLORMARKDOWN
+      end
+    end
+  end
+end

spec/anything_spec.rb

@@ -1,39 +1,61 @@
 require 'spec_hepler'
+require_relative '../lib/strategies/markdown'
+require_relative '../lib/strategies/html'
 require_relative '../lib/generators/base'
-require_relative '../lib/generators/html'
-require_relative '../lib/generators/markdown'
+require_relative '../lib/generators/good_news'
+require_relative '../lib/generators/bad_news'
 
 module Newsletter
   describe Generators::Base do
     context 'when HTML' do
-      let(:newsletter) do
-        File.read(
-          File.expand_path('fixtures/newsletter.html', File.dirname(__FILE__))
-        )
+      context 'when news are good' do
+        let(:newsletter) do
+          File.read(
+            File.expand_path('fixtures/good_news.html', File.dirname(__FILE__))
+          )
+        end
+
+        it 'generates HTML' do
+          expect(Generators::GoodNews.new(strategy: :Html).render).to include(newsletter)
+        end
       end
 
-      it 'generates HTML' do
-        expect(Generators::Html.new.render).to include(newsletter)
+      context 'when news are bad' do
+        let(:newsletter) do
+          File.read(
+            File.expand_path('fixtures/bad_news.html', File.dirname(__FILE__))
+          )
+        end
+
+        it 'generates HTML' do
+          expect(Generators::BadNews.new(strategy: :Html).render).to include(newsletter)
+        end
       end
     end
 
     context 'when markdown' do
-      let(:newsletter) do
-        File.read(
-          File.expand_path('fixtures/newsletter.markdown', File.dirname(__FILE__))
-        )
-      end
+      context 'when news are good' do
+        let(:newsletter) do
+          File.read(
+            File.expand_path('fixtures/good_news.markdown', File.dirname(__FILE__))
+          )
+        end
 
-      it 'generates markdown' do
-        expect(Newsletter::Generators::Markdown.new.render).to include(newsletter)
+        it 'generates markdown' do
+          expect(Generators::GoodNews.new(strategy: :Markdown).render).to include(newsletter)
+        end
       end
-    end
 
-    context 'when we calling the base class' do
-      it 'Template method requires base class to ba abstract!!!' do
-        expect{ Generators::Base.new.render }.to raise_error(NotImplementedError)
-        expect{ Generators::Base.new.header }.to raise_error(NotImplementedError)
-        expect{ Generators::Base.new.body }.to raise_error(NotImplementedError)
+      context 'when news are bad' do
+        let(:newsletter) do
+          File.read(
+            File.expand_path('fixtures/bad_news.markdown', File.dirname(__FILE__))
+          )
+        end
+
+        it 'generates markdown' do
+          expect(Generators::BadNews.new(strategy: :Markdown).render).to include(newsletter)
+        end
       end
     end
   end

spec/fixtures/bad_news.html

@@ -0,0 +1,3 @@
+<h1>BAD</h1>
+
+<p>NEWS</p>

spec/fixtures/bad_news.markdown

@@ -0,0 +1,5 @@
+**********
+# BAD
+**********
+NEWS
+**********

spec/fixtures/good_news.html

@@ -0,0 +1,3 @@
+<h1>GOOD</h1>
+
+<p>NEWS</p>

spec/fixtures/good_news.markdown

@@ -0,0 +1,5 @@
+**********
+# GOOD
+**********
+NEWS
+**********