Extract the abstract base class of badge metadata

lib/gitlab/badge/build/metadata.rb

@@ -4,22 +4,14 @@ module Gitlab
       ##
       # Class that describes build badge metadata
       #
-      class Metadata
-        include Gitlab::Application.routes.url_helpers
-        include ActionView::Helpers::AssetTagHelper
-        include ActionView::Helpers::UrlHelper
-
+      class Metadata < Badge::Metadata
         def initialize(badge)
           @project = badge.project
           @ref = badge.ref
         end
 
-        def to_html
-          link_to(image_tag(image_url, alt: 'build status'), link_url)
-        end
-
-        def to_markdown
-          "[![build status](#{image_url})](#{link_url})"
+        def title
+          'build status'
         end
 
         def image_url

lib/gitlab/badge/coverage/metadata.rb

@@ -4,23 +4,15 @@ module Gitlab
       ##
       # Class that describes coverage badge metadata
       #
-      class Metadata
-        include Gitlab::Application.routes.url_helpers
-        include ActionView::Helpers::AssetTagHelper
-        include ActionView::Helpers::UrlHelper
-
+      class Metadata < Badge::Metadata
         def initialize(badge)
           @project = badge.project
           @ref = badge.ref
           @job = badge.job
         end
 
-        def to_html
-          link_to(image_tag(image_url, alt: 'coverage report'), link_url)
-        end
-
-        def to_markdown
-          "[![coverage report](#{image_url})](#{link_url})"
+        def title
+          'coverage report'
         end
 
         def image_url

lib/gitlab/badge/metadata.rb

+module Gitlab
+  module Badge
+    ##
+    # Abstract class for badge metadata
+    #
+    class Metadata
+      include Gitlab::Application.routes.url_helpers
+      include ActionView::Helpers::AssetTagHelper
+      include ActionView::Helpers::UrlHelper
+
+      def initialize(badge)
+        @badge = badge
+      end
+
+      def to_html
+        link_to(image_tag(image_url, alt: title), link_url)
+      end
+
+      def to_markdown
+        "[![#{title}](#{image_url})](#{link_url})"
+      end
+
+      def title
+        raise NotImplementedError
+      end
+
+      def image_url
+        raise NotImplementedError
+      end
+
+      def link_url
+        raise NotImplementedError
+      end
+    end
+  end
+end

spec/lib/gitlab/badge/build/metadata_spec.rb

@@ -7,6 +7,12 @@ describe Gitlab::Badge::Build::Metadata do
 
   it_behaves_like 'badge metadata'
 
+  describe '#title' do
+    it 'returns build status title' do
+      expect(metadata.title).to eq 'build status'
+    end
+  end
+
   describe '#image_url' do
     it 'returns valid url' do
       expect(metadata.image_url).to include 'badges/feature/build.svg'

spec/lib/gitlab/badge/coverage/metadata_spec.rb

@@ -10,6 +10,12 @@ describe Gitlab::Badge::Coverage::Metadata do
 
   it_behaves_like 'badge metadata'
 
+  describe '#title' do
+    it 'returns coverage report title' do
+      expect(metadata.title).to eq 'coverage report'
+    end
+  end
+
   describe '#image_url' do
     it 'returns valid url' do
       expect(metadata.image_url).to include 'badges/feature/coverage.svg'