1 files changed, 68 insertions, 0 deletions
diff --git a/app/models/concerns/noteable.rb b/app/models/concerns/noteable.rb
new file mode 100644
index 00000000000..dd1e6630642
--- /dev/null
+++ b/app/models/concerns/noteable.rb
@@ -0,0 +1,68 @@
+module Noteable
+  # Names of all implementers of `Noteable` that support resolvable notes.
+  RESOLVABLE_TYPES = %w(MergeRequest).freeze
+
+  def base_class_name
+    self.class.base_class.name
+  end
+
+  # Convert this Noteable class name to a format usable by notifications.
+  #
+  # Examples:
+  #
+  #   noteable.class           # => MergeRequest
+  #   noteable.human_class_name # => "merge request"
+  def human_class_name
+    @human_class_name ||= base_class_name.titleize.downcase
+  end
+
+  def supports_resolvable_notes?
+    RESOLVABLE_TYPES.include?(base_class_name)
+  end
+
+  def supports_discussions?
+    DiscussionNote::NOTEABLE_TYPES.include?(base_class_name)
+  end
+
+  def discussion_notes
+    notes
+  end
+
+  delegate :find_discussion, to: :discussion_notes
+
+  def discussions
+    @discussions ||= discussion_notes
+      .inc_relations_for_view
+      .discussions(self)
+  end
+
+  def grouped_diff_discussions(*args)
+    # Doesn't use `discussion_notes`, because this may include commit diff notes
+    # besides MR diff notes, that we do no want to display on the MR Changes tab.
+    notes.inc_relations_for_view.grouped_diff_discussions(*args)
+  end
+
+  def resolvable_discussions
+    @resolvable_discussions ||= discussion_notes.resolvable.discussions(self)
+  end
+
+  def discussions_resolvable?
+    resolvable_discussions.any?(&:resolvable?)
+  end
+
+  def discussions_resolved?
+    discussions_resolvable? && resolvable_discussions.none?(&:to_be_resolved?)
+  end
+
+  def discussions_to_be_resolved?
+    discussions_resolvable? && !discussions_resolved?
+  end
+
+  def discussions_to_be_resolved
+    @discussions_to_be_resolved ||= resolvable_discussions.select(&:to_be_resolved?)
+  end
+
+  def discussions_can_be_resolved_by?(user)
+    discussions_to_be_resolved.all? { |discussion| discussion.can_resolve?(user) }
+  end
+end