Change project to a polymorphic on labels

7 files changed, 48 insertions, 18 deletions

diff --git a/app/models/label.rb b/app/models/label.rb
index a23140b7d64..1a0ad02567b 100644
--- a/app/models/label.rb
+++ b/app/models/label.rb
@@ -12,7 +12,7 @@ class Label < ActiveRecord::Base
 
   default_value_for :color, DEFAULT_COLOR
 
-  belongs_to :project
+  belongs_to :subject, polymorphic: true
 
   has_many :lists, dependent: :destroy
   has_many :label_links, dependent: :destroy
@@ -20,13 +20,13 @@ class Label < ActiveRecord::Base
   has_many :merge_requests, through: :label_links, source: :target, source_type: 'MergeRequest'
 
   validates :color, color: true, allow_blank: false
-  validates :project, presence: true, unless: Proc.new { |service| service.template? }
+  validates :subject, presence: true, unless: Proc.new { |service| service.template? }
 
   # Don't allow ',' for label titles
   validates :title,
             presence: true,
             format: { with: /\A[^,]+\z/ },
-            uniqueness: { scope: :project_id }
+            uniqueness: { scope: :subject_id }
 
   before_save :nullify_priority
 
@@ -92,7 +92,7 @@ class Label < ActiveRecord::Base
     reference = "#{self.class.reference_prefix}#{format_reference}"
 
     if cross_project_reference?(from_project)
-      project.to_reference + reference
+      subject.to_reference + reference
     else
       reference
     end
@@ -124,6 +124,14 @@ class Label < ActiveRecord::Base
 
   private
 
+  def cross_project_reference?(from_project)
+    if self.is_a?(Project)
+      self != from_project
+    else
+      from_project && self.subject && self.subject != from_project
+    end
+  end
+
   def label_format_reference(format = :id)
     raise StandardError, 'Unknown format' unless [:id, :name].include?(format)
 
diff --git a/app/models/project.rb b/app/models/project.rb
index 8b5a6f167bd..57b5e4f5973 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -101,7 +101,7 @@ class Project < ActiveRecord::Base
   # Merge requests from source project should be kept when source project was removed
   has_many :fork_merge_requests, foreign_key: 'source_project_id', class_name: MergeRequest
   has_many :issues,             dependent: :destroy
-  has_many :labels,             dependent: :destroy
+  has_many :labels,             dependent: :destroy, as: :subject
   has_many :services,           dependent: :destroy
   has_many :events,             dependent: :destroy
   has_many :milestones,         dependent: :destroy
@@ -733,7 +733,7 @@ class Project < ActiveRecord::Base
     Label.templates.each do |label|
       label = label.dup
       label.template = nil
-      label.project_id = self.id
+      label.subject = self
       label.save
     end
   end
diff --git a/db/migrate/20160902152513_change_project_to_polymorphic_relationship_on_labels.rb b/db/migrate/20160902152513_change_project_to_polymorphic_relationship_on_labels.rb
new file mode 100644
index 00000000000..a2963109177
--- /dev/null
+++ b/db/migrate/20160902152513_change_project_to_polymorphic_relationship_on_labels.rb
@@ -0,0 +1,20 @@
+class ChangeProjectToPolymorphicRelationshipOnLabels < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = true
+  DOWNTIME_REASON = 'This migration renames an existing column'
+
+  disable_ddl_transaction!
+
+  def up
+    rename_column :labels, :project_id, :subject_id
+    add_column :labels, :subject_type, :string
+    update_column_in_batches :labels, :subject_type, 'Project'
+    add_concurrent_index :labels, :subject_type
+  end
+
+  def down
+    rename_column :labels, :subject_id, :project_id
+    remove_column :labels, :subject_type
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 974f5855cf9..8c30faa8df3 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -497,16 +497,18 @@ ActiveRecord::Schema.define(version: 20160913212128) do
   create_table "labels", force: :cascade do |t|
     t.string   "title"
     t.string   "color"
-    t.integer  "project_id"
+    t.integer  "subject_id"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.boolean  "template",    default: false
+    t.boolean  "template",     default: false
     t.string   "description"
     t.integer  "priority"
+    t.string   "subject_type"
   end
 
   add_index "labels", ["priority"], name: "index_labels_on_priority", using: :btree
-  add_index "labels", ["project_id"], name: "index_labels_on_project_id", using: :btree
+  add_index "labels", ["subject_id"], name: "index_labels_on_subject_id", using: :btree
+  add_index "labels", ["subject_type"], name: "index_labels_on_subject_type", using: :btree
 
   create_table "lfs_objects", force: :cascade do |t|
     t.string   "oid",                  null: false
diff --git a/spec/factories/labels.rb b/spec/factories/labels.rb
index eb489099854..942080b8644 100644
--- a/spec/factories/labels.rb
+++ b/spec/factories/labels.rb
@@ -2,6 +2,6 @@ FactoryGirl.define do
   factory :label do
     sequence(:title) { |n| "label#{n}" }
     color "#990000"
-    project
+    subject factory: :project
   end
 end
diff --git a/spec/models/concerns/issuable_spec.rb b/spec/models/concerns/issuable_spec.rb
index 60e4bbc8564..bd1144b2c20 100644
--- a/spec/models/concerns/issuable_spec.rb
+++ b/spec/models/concerns/issuable_spec.rb
@@ -256,7 +256,7 @@ describe Issue, "Issuable" do
 
   describe '#labels_array' do
     let(:project) { create(:project) }
-    let(:bug) { create(:label, project: project, title: 'bug') }
+    let(:bug) { create(:label, subject: project, title: 'bug') }
     let(:issue) { create(:issue, project: project) }
 
     before(:each) do
@@ -300,9 +300,9 @@ describe Issue, "Issuable" do
 
   describe ".with_label" do
     let(:project) { create(:project, :public) }
-    let(:bug) { create(:label, project: project, title: 'bug') }
-    let(:feature) { create(:label, project: project, title: 'feature') }
-    let(:enhancement) { create(:label, project: project, title: 'enhancement') }
+    let(:bug) { create(:label, subject: project, title: 'bug') }
+    let(:feature) { create(:label, subject: project, title: 'feature') }
+    let(:enhancement) { create(:label, subject: project, title: 'enhancement') }
     let(:issue1) { create(:issue, title: "Bugfix1", project: project) }
     let(:issue2) { create(:issue, title: "Bugfix2", project: project) }
     let(:issue3) { create(:issue, title: "Feature1", project: project) }
diff --git a/spec/models/label_spec.rb b/spec/models/label_spec.rb
index 5a5d1a5d60c..bdd75cc760e 100644
--- a/spec/models/label_spec.rb
+++ b/spec/models/label_spec.rb
@@ -4,7 +4,7 @@ describe Label, models: true do
   let(:label) { create(:label) }
 
   describe 'associations' do
-    it { is_expected.to belong_to(:project) }
+    it { is_expected.to belong_to(:subject) }
 
     it { is_expected.to have_many(:label_links).dependent(:destroy) }
     it { is_expected.to have_many(:issues).through(:label_links).source(:target) }
@@ -18,7 +18,7 @@ describe Label, models: true do
   end
 
   describe 'validation' do
-    it { is_expected.to validate_presence_of(:project) }
+    it { is_expected.to validate_presence_of(:subject) }
 
     it 'validates color code' do
       expect(label).not_to allow_value('G-ITLAB').for(:color)
@@ -82,14 +82,14 @@ describe Label, models: true do
       context 'using name' do
         it 'returns cross reference with label name' do
           expect(label.to_reference(project, format: :name))
-            .to eq %Q(#{label.project.to_reference}~"#{label.name}")
+            .to eq %Q(#{label.subject.to_reference}~"#{label.name}")
         end
       end
 
       context 'using id' do
         it 'returns cross reference with label id' do
           expect(label.to_reference(project, format: :id))
-            .to eq %Q(#{label.project.to_reference}~#{label.id})
+            .to eq %Q(#{label.subject.to_reference}~#{label.id})
         end
       end
     end