Have Issue#participants load all users mentioned in notes using a single query

1 files changed, 13 insertions, 10 deletions

diff --git a/app/models/concerns/participable.rb b/app/models/concerns/participable.rb
index 7c9597333dd..7a2bea567df 100644
--- a/app/models/concerns/participable.rb
+++ b/app/models/concerns/participable.rb
@@ -27,7 +27,7 @@ module Participable
 
   module ClassMethods
     def participant(*attrs)
-      participant_attrs.concat(attrs.map(&:to_s))
+      participant_attrs.concat(attrs)
     end
 
     def participant_attrs
@@ -37,13 +37,12 @@ module Participable
 
   # Be aware that this method makes a lot of sql queries.
   # Save result into variable if you are going to reuse it inside same request
-  def participants(current_user = self.author, project = self.project)
+  def participants(current_user = self.author, project = self.project, load_lazy_references: true)
     participants = self.class.participant_attrs.flat_map do |attr|
       meth = method(attr)
-
       value =
-        if meth.arity == 1 || meth.arity == -1
-          meth.call(current_user)
+        if attr == :mentioned_users
+          meth.call(current_user, load_lazy_references: false)
         else
           meth.call
         end
@@ -51,9 +50,13 @@ module Participable
       participants_for(value, current_user, project)
     end.compact.uniq
 
-    if project
-      participants.select! do |user|
-        user.can?(:read_project, project)
+    if load_lazy_references
+      participants = Gitlab::Markdown::ReferenceFilter::LazyReference.load(participants).uniq
+
+      if project
+        participants.select! do |user|
+          user.can?(:read_project, project)
+        end
       end
     end
 
@@ -64,12 +67,12 @@ module Participable
 
   def participants_for(value, current_user = nil, project = nil)
     case value
-    when User
+    when User, Gitlab::Markdown::ReferenceFilter::LazyReference
       [value]
     when Enumerable, ActiveRecord::Relation
       value.flat_map { |v| participants_for(v, current_user, project) }
     when Participable
-      value.participants(current_user, project)
+      value.participants(current_user, project, load_lazy_references: false)
     end
   end
 end