Added relationships between Release and Milestone

Modified schema via migrations.
Added one-to-one relationship between the two models.
Added changelog file

6 files changed, 58 insertions, 1 deletions

diff --git a/app/models/milestone.rb b/app/models/milestone.rb
index 2ad2838111e..101e963ea29 100644
--- a/app/models/milestone.rb
+++ b/app/models/milestone.rb
@@ -24,6 +24,12 @@ class Milestone < ApplicationRecord
   belongs_to :project
   belongs_to :group
 
+  # A one-to-one relationship is set up here as part of a MVC: https://gitlab.com/gitlab-org/gitlab-ce/issues/62402
+  # However, on the long term, we will want a many-to-many relationship between Release and Milestone.
+  # The "has_one through" allows us today to set up this one-to-one relationship while setting up the architecture for the long-term (ie intermediate table).
+  has_one :milestone_release
+  has_one :release, through: :milestone_release
+
   has_internal_id :iid, scope: :project, init: ->(s) { s&.project&.milestones&.maximum(:iid) }
   has_internal_id :iid, scope: :group, init: ->(s) { s&.group&.milestones&.maximum(:iid) }
 
@@ -59,6 +65,7 @@ class Milestone < ApplicationRecord
   validate :milestone_type_check
   validate :start_date_should_be_less_than_due_date, if: proc { |m| m.start_date.present? && m.due_date.present? }
   validate :dates_within_4_digits
+  validates_associated :milestone_release, message: -> (_, obj) { obj[:value].errors.full_messages.join(",") }
 
   strip_attributes :title
 
diff --git a/app/models/milestone_release.rb b/app/models/milestone_release.rb
new file mode 100644
index 00000000000..c8743a8cad8
--- /dev/null
+++ b/app/models/milestone_release.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class MilestoneRelease < ApplicationRecord
+  belongs_to :milestone
+  belongs_to :release
+
+  validates :milestone_id, uniqueness: { scope: [:release_id] }
+  validate :same_project_between_milestone_and_release
+
+  private
+
+  def same_project_between_milestone_and_release
+    return if milestone&.project_id == release&.project_id
+
+    errors.add(:base, 'does not have the same project as the milestone')
+  end
+end
diff --git a/app/models/release.rb b/app/models/release.rb
index 459a7c29ad0..b2e65974aa0 100644
--- a/app/models/release.rb
+++ b/app/models/release.rb
@@ -12,6 +12,12 @@ class Release < ApplicationRecord
 
   has_many :links, class_name: 'Releases::Link'
 
+  # A one-to-one relationship is set up here as part of a MVC: https://gitlab.com/gitlab-org/gitlab-ce/issues/62402
+  # However, on the long term, we will want a many-to-many relationship between Release and Milestone.
+  # The "has_one through" allows us today to set up this one-to-one relationship while setting up the architecture for the long-term (ie intermediate table).
+  has_one :milestone_release
+  has_one :milestone, through: :milestone_release
+
   default_value_for :released_at, allows_nil: false do
     Time.zone.now
   end
@@ -20,6 +26,7 @@ class Release < ApplicationRecord
 
   validates :description, :project, :tag, presence: true
   validates :name, presence: true, on: :create
+  validates_associated :milestone_release, message: -> (_, obj) { obj[:value].errors.full_messages.join(",") }
 
   scope :sorted, -> { order(released_at: :desc) }
 
diff --git a/app/services/releases/concerns.rb b/app/services/releases/concerns.rb
index 618d96717b8..b5412e97284 100644
--- a/app/services/releases/concerns.rb
+++ b/app/services/releases/concerns.rb
@@ -47,6 +47,27 @@ module Releases
           project.repository
         end
       end
+
+      def milestone
+        return unless params[:milestone]
+
+        strong_memoize(:milestone) do
+          MilestonesFinder.new(
+            project: project,
+            current_user: current_user,
+            project_ids: Array(project.id),
+            title: params[:milestone]
+          ).execute.first
+        end
+      end
+
+      def inexistent_milestone?
+        params[:milestone] && !params[:milestone].empty? && !milestone
+      end
+
+      def param_for_milestone_title_provided?
+        params[:milestone].present? || params[:milestone]&.empty?
+      end
     end
   end
 end
diff --git a/app/services/releases/create_service.rb b/app/services/releases/create_service.rb
index 5b13ac631ba..c91d43084d3 100644
--- a/app/services/releases/create_service.rb
+++ b/app/services/releases/create_service.rb
@@ -7,6 +7,7 @@ module Releases
     def execute
       return error('Access Denied', 403) unless allowed?
       return error('Release already exists', 409) if release
+      return error('Milestone does not exist', 400) if inexistent_milestone?
 
       tag = ensure_tag
 
@@ -59,7 +60,8 @@ module Releases
         tag: tag.name,
         sha: tag.dereferenced_target.sha,
         released_at: released_at,
-        links_attributes: params.dig(:assets, 'links') || []
+        links_attributes: params.dig(:assets, 'links') || [],
+        milestone: milestone
       )
     end
   end
diff --git a/app/services/releases/update_service.rb b/app/services/releases/update_service.rb
index fabfa398c59..70acc68f747 100644
--- a/app/services/releases/update_service.rb
+++ b/app/services/releases/update_service.rb
@@ -9,6 +9,9 @@ module Releases
       return error('Release does not exist', 404) unless release
       return error('Access Denied', 403) unless allowed?
       return error('params is empty', 400) if empty_params?
+      return error('Milestone does not exist', 400) if inexistent_milestone?
+
+      params[:milestone] = milestone if param_for_milestone_title_provided?
 
       if release.update(params)
         success(tag: existing_tag, release: release)