Add subject to group and projects labels which return group/project

app/helpers/labels_helper.rb

@@ -14,7 +14,7 @@ module LabelsHelper
   #
   # Examples:
   #
-  #   # Allow the generated link to use the label's own project
+  #   # Allow the generated link to use the label's own subject
   #   link_to_label(label)
   #
   #   # Force the generated link to use a provided group
@@ -31,13 +31,7 @@ module LabelsHelper
   #
   # Returns a String
   def link_to_label(label, subject: nil, type: :issue, tooltip: true, css_class: nil, &block)
-    subject ||=
-      case label
-      when GroupLabel then label.group
-      when ProjectLabel then label.project
-      end
-
-    link = label_filter_path(subject, label, type: type)
+    link = label_filter_path(subject || label.subject, label, type: type)
 
     if block_given?
       link_to link, class: css_class, &block

app/models/group_label.rb

@@ -3,6 +3,8 @@ class GroupLabel < Label
 
   validates :group, presence: true
 
+  alias_attribute :subject, :group
+
   def to_reference(source_project = nil, target_project = nil, format: :id)
     super(source_project, target_project, format: format)
   end

app/models/project_label.rb

@@ -10,6 +10,8 @@ class ProjectLabel < Label
 
   delegate :group, to: :project, allow_nil: true
 
+  alias_attribute :subject, :project
+
   def to_reference(target_project = nil, format: :id)
     super(project, target_project, format: format)
   end

spec/models/group_label_spec.rb

@@ -9,6 +9,14 @@
     it { is_expected.to validate_presence_of(:group) }
   end
 
+  describe '#subject' do
+    it 'aliases group to subject' do
+      subject = described_class.new(group: build(:group))
+
+      expect(subject.subject).to be(subject.group)
+    end
+  end
+
   describe '#to_reference' do
     let(:label) { create(:group_label) }
 

spec/models/project_label_spec.rb

@@ -64,6 +64,14 @@
     end
   end
 
+  describe '#subject' do
+    it 'aliases project to subject' do
+      subject = described_class.new(project: build(:empty_project))
+
+      expect(subject.subject).to be(subject.project)
+    end
+  end
+
   describe '#to_reference' do
     let(:label) { create(:label) }