Fix issue board related controllers to expose label priority per project

app/controllers/projects/boards/issues_controller.rb

@@ -72,10 +72,10 @@ module Projects
 
       def serialize_as_json(resource)
         resource.as_json(
+          labels: true,
           only: [:iid, :title, :confidential],
           include: {
-            assignee: { only: [:id, :name, :username], methods: [:avatar_url] },
-            labels:   { only: [:id, :title, :description, :color, :priority], methods: [:text_color] }
+            assignee: { only: [:id, :name, :username], methods: [:avatar_url] }
           })
       end
     end

app/controllers/projects/boards/lists_controller.rb

@@ -76,9 +76,8 @@ module Projects
         resource.as_json(
           only: [:id, :list_type, :position],
           methods: [:title],
-          include: {
-            label: { only: [:id, :title, :description, :color, :priority] }
-          })
+          label: true
+        )
       end
     end
   end

app/models/issue.rb

@@ -274,4 +274,16 @@ class Issue < ActiveRecord::Base
   def check_for_spam?
     project.public?
   end
+
+  def as_json(options = {})
+    super(options).tap do |json|
+      if options.has_key?(:labels)
+        json[:labels] = labels.as_json(
+          project: project,
+          only: [:id, :title, :description, :color],
+          methods: [:text_color]
+        )
+      end
+    end
+  end
 end

app/models/label.rb

@@ -133,6 +133,12 @@ class Label < ActiveRecord::Base
     end
   end
 
+  def as_json(options = {})
+    super(options).tap do |json|
+      json[:priority] = priorities.find_by(project: options[:project]).try(:priority) if options.has_key?(:project)
+    end
+  end
+
   private
 
   def cross_project_reference?(source_project, target_project)

app/models/list.rb

@@ -26,6 +26,17 @@ class List < ActiveRecord::Base
     label? ? label.name : list_type.humanize
   end
 
+  def as_json(options = {})
+    super(options).tap do |json|
+      if options.has_key?(:label)
+        json[:label] = label.as_json(
+          project: board.project,
+          only: [:id, :title, :description, :color]
+        )
+      end
+    end
+  end
+
   private
 
   def can_be_destroyed

spec/fixtures/api/schemas/list.json

@@ -13,7 +13,7 @@
       "enum": ["backlog", "label", "done"]
     },
     "label": {
-      "type": ["object"],
+      "type": ["object", "null"],
       "required": [
         "id",
         "color",