Allow sorting by most or least comments on Issues and Merge Requestsadam-sort-by-comments

4 files changed, 52 insertions, 1 deletions

diff --git a/app/helpers/sorting_helper.rb b/app/helpers/sorting_helper.rb
index ff787fb4131..3239d0552b7 100644
--- a/app/helpers/sorting_helper.rb
+++ b/app/helpers/sorting_helper.rb
@@ -16,7 +16,9 @@ module SortingHelper
       sort_value_oldest_signin => sort_title_oldest_signin,
       sort_value_downvotes => sort_title_downvotes,
       sort_value_upvotes => sort_title_upvotes,
-      sort_value_priority => sort_title_priority
+      sort_value_priority => sort_title_priority,
+      sort_value_most_comments => sort_title_most_comments,
+      sort_value_least_comments => sort_title_least_comments
     }
   end
 
@@ -137,6 +139,14 @@ module SortingHelper
     'Name, descending'
   end
 
+  def sort_title_most_comments
+    'Most comments'
+  end
+
+  def sort_title_least_comments
+    'Least comments'
+  end
+
   def sort_value_last_joined
     'last_joined'
   end
@@ -220,4 +230,12 @@ module SortingHelper
   def sort_value_upvotes
     'upvotes_desc'
   end
+
+  def sort_value_most_comments
+    'comments_desc'
+  end
+
+  def sort_value_least_comments
+    'comments_asc'
+  end
 end
diff --git a/app/models/concerns/issuable.rb b/app/models/concerns/issuable.rb
index 3517969eabc..94f05e7285f 100644
--- a/app/models/concerns/issuable.rb
+++ b/app/models/concerns/issuable.rb
@@ -139,6 +139,8 @@ module Issuable
                when 'downvotes_desc' then order_downvotes_desc
                when 'upvotes_desc' then order_upvotes_desc
                when 'priority' then order_labels_priority(excluded_labels: excluded_labels)
+               when 'comments_desc' then order_most_comments
+               when 'comments_asc' then order_least_comments
                else
                  order_by(method)
                end
@@ -189,6 +191,29 @@ module Issuable
     def to_ability_name
       model_name.singular
     end
+
+    def order_most_comments
+      order_comments('DESC')
+    end
+
+    def order_least_comments
+      order_comments('ASC')
+    end
+
+    def order_comments(comments_order)
+      issuable_table = self.arel_table
+      note_table = Note.arel_table
+
+      join_clause = issuable_table.join(note_table, Arel::Nodes::OuterJoin).on(
+        note_table[:noteable_id].eq(issuable_table[:id]).and(
+          note_table[:noteable_type].eq(self.name).and(
+            note_table[:system].eq(false)
+          )
+        )
+      ).join_sources
+
+      joins(join_clause).group(issuable_table[:id]).reorder("COUNT(notes.id) " + comments_order)
+    end
   end
 
   def today?
diff --git a/app/views/shared/_sort_dropdown.html.haml b/app/views/shared/_sort_dropdown.html.haml
index 0ce0d759e86..c00ddf2db41 100644
--- a/app/views/shared/_sort_dropdown.html.haml
+++ b/app/views/shared/_sort_dropdown.html.haml
@@ -31,3 +31,7 @@
         = sort_title_upvotes
       = link_to page_filter_path(sort: sort_value_downvotes, label: true) do
         = sort_title_downvotes
+      = link_to page_filter_path(sort: sort_value_most_comments, label: true) do
+        = sort_title_most_comments
+      = link_to page_filter_path(sort: sort_value_least_comments, label: true) do
+        = sort_title_least_comments
diff --git a/changelogs/unreleased/adam-sort-by-comments.yml b/changelogs/unreleased/adam-sort-by-comments.yml
new file mode 100644
index 00000000000..61b3fcdcf87
--- /dev/null
+++ b/changelogs/unreleased/adam-sort-by-comments.yml
@@ -0,0 +1,4 @@
+---
+title: Allow sorting by most or least comments on Issues
+merge_request: 8783
+author: Alex Clifford