Remove label issue and MR counts from default API responses

These counts significantly increase the load time for these
requests. Users can now opt in to receiving the counts by setting
`with_counts=true` in requests. This is a breaking change, but hopefully
a fairly minor one.

4 files changed, 19 insertions, 9 deletions

diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 2f5ce3d4003..70201502b57 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -1085,16 +1085,18 @@ module API
     end
 
     class Label < LabelBasic
-      expose :open_issues_count do |label, options|
-        label.open_issues_count(options[:current_user])
-      end
+      with_options if: lambda { |_, options| options[:with_counts] } do
+        expose :open_issues_count do |label, options|
+          label.open_issues_count(options[:current_user])
+        end
 
-      expose :closed_issues_count do |label, options|
-        label.closed_issues_count(options[:current_user])
-      end
+        expose :closed_issues_count do |label, options|
+          label.closed_issues_count(options[:current_user])
+        end
 
-      expose :open_merge_requests_count do |label, options|
-        label.open_merge_requests_count(options[:current_user])
+        expose :open_merge_requests_count do |label, options|
+          label.open_merge_requests_count(options[:current_user])
+        end
       end
 
       expose :subscribed do |label, options|
diff --git a/lib/api/group_labels.rb b/lib/api/group_labels.rb
index 0dbc5f45a68..79a44941c81 100644
--- a/lib/api/group_labels.rb
+++ b/lib/api/group_labels.rb
@@ -16,6 +16,8 @@ module API
         success Entities::GroupLabel
       end
       params do
+        optional :with_counts, type: Boolean, default: false,
+                 desc: 'Include issue and merge request counts'
         use :pagination
       end
       get ':id/labels' do
diff --git a/lib/api/helpers/label_helpers.rb b/lib/api/helpers/label_helpers.rb
index c11e7d614ab..896b0aba52b 100644
--- a/lib/api/helpers/label_helpers.rb
+++ b/lib/api/helpers/label_helpers.rb
@@ -19,7 +19,11 @@ module API
       end
 
       def get_labels(parent, entity)
-        present paginate(available_labels_for(parent)), with: entity, current_user: current_user, parent: parent
+        present paginate(available_labels_for(parent)),
+                with: entity,
+                current_user: current_user,
+                parent: parent,
+                with_counts: params[:with_counts]
       end
 
       def create_label(parent, entity)
diff --git a/lib/api/labels.rb b/lib/api/labels.rb
index d729d3ee625..c183198d3c6 100644
--- a/lib/api/labels.rb
+++ b/lib/api/labels.rb
@@ -15,6 +15,8 @@ module API
         success Entities::ProjectLabel
       end
       params do
+        optional :with_counts, type: Boolean, default: false,
+                 desc: 'Include issue and merge request counts'
         use :pagination
       end
       get ':id/labels' do