1 files changed, 32 insertions, 0 deletions
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 12c5481cd6d..35231bab12e 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -17,6 +17,8 @@ class MergeRequest < ActiveRecord::Base
 
   has_many :merge_requests_closing_issues, class_name: 'MergeRequestsClosingIssues', dependent: :delete_all
 
+  belongs_to :assignee, class_name: "User"
+
   serialize :merge_params, Hash
 
   after_create :ensure_merge_request_diff, unless: :importing?
@@ -114,8 +116,14 @@ class MergeRequest < ActiveRecord::Base
 
   scope :join_project, -> { joins(:target_project) }
   scope :references_project, -> { references(:target_project) }
+  scope :assigned, -> { where("assignee_id IS NOT NULL") }
+  scope :unassigned, -> { where("assignee_id IS NULL") }
+  scope :assigned_to, ->(u) { where(assignee_id: u.id)}
+
+  participant :assignee
 
   after_save :keep_around_commit
+  after_save :update_assignee_cache_counts, if: :assignee_id_changed?
 
   def self.reference_prefix
     '!'
@@ -177,6 +185,30 @@ class MergeRequest < ActiveRecord::Base
     work_in_progress?(title) ? title : "WIP: #{title}"
   end
 
+  def update_assignee_cache_counts
+    # make sure we flush the cache for both the old *and* new assignees(if they exist)
+    previous_assignee = User.find_by_id(assignee_id_was) if assignee_id_was
+    previous_assignee&.update_cache_counts
+    assignee&.update_cache_counts
+  end
+
+  # Returns a Hash of attributes to be used for Twitter card metadata
+  def card_attributes
+    {
+      'Author'   => author.try(:name),
+      'Assignee' => assignee.try(:name)
+    }
+  end
+
+  # This method is needed for compatibility with issues to not mess view and other code
+  def assignees
+    Array(assignee)
+  end
+
+  def assignee_or_author?(user)
+    author_id == user.id || assignee_id == user.id
+  end
+
   # `from` argument can be a Namespace or Project.
   def to_reference(from = nil, full: false)
     reference = "#{self.class.reference_prefix}#{iid}"