1 files changed, 62 insertions, 0 deletions
diff --git a/app/models/concerns/approvable.rb b/app/models/concerns/approvable.rb
new file mode 100644
index 00000000000..1566c53217d
--- /dev/null
+++ b/app/models/concerns/approvable.rb
@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+
+module Approvable
+  extend ActiveSupport::Concern
+  include FromUnion
+
+  included do
+    has_many :approvals, dependent: :delete_all # rubocop:disable Cop/ActiveRecordDependent
+    has_many :approved_by_users, through: :approvals, source: :user
+
+    scope :without_approvals, -> { left_outer_joins(:approvals).where(approvals: { id: nil }) }
+    scope :with_approvals, -> { joins(:approvals) }
+    scope :approved_by_users_with_ids, -> (*user_ids) do
+      with_approvals
+        .merge(Approval.with_user)
+        .where(users: { id: user_ids })
+        .group(:id)
+        .having("COUNT(users.id) = ?", user_ids.size)
+    end
+    scope :approved_by_users_with_usernames, -> (*usernames) do
+      with_approvals
+        .merge(Approval.with_user)
+        .where(users: { username: usernames })
+        .group(:id)
+        .having("COUNT(users.id) = ?", usernames.size)
+    end
+
+    scope :not_approved_by_users_with_usernames, -> (usernames) do
+      users = User.where(username: usernames).select(:id)
+      app_table = Approval.arel_table
+
+      where(
+        Approval.where(approvals: { user_id: users })
+        .where(app_table[:merge_request_id].eq(arel_table[:id]))
+        .select('true')
+        .arel.exists.not
+      )
+    end
+  end
+
+  class_methods do
+    def select_from_union(relations)
+      where(id: from_union(relations))
+    end
+  end
+
+  def approved_by?(user)
+    return false unless user
+
+    approvals.where(user: user).any?
+  end
+
+  def can_be_approved_by?(user)
+    user && !approved_by?(user) && user.can?(:approve_merge_request, self)
+  end
+
+  def can_be_unapproved_by?(user)
+    user && approved_by?(user) && user.can?(:approve_merge_request, self)
+  end
+end
+
+Approvable.prepend_mod