1 files changed, 14 insertions, 0 deletions
diff --git a/app/graphql/types/base_object.rb b/app/graphql/types/base_object.rb
index 70e665f8fc3..9c36c83d4a3 100644
--- a/app/graphql/types/base_object.rb
+++ b/app/graphql/types/base_object.rb
@@ -8,6 +8,12 @@ module Types
 
     field_class Types::BaseField
 
+    def self.accepts(*types)
+      @accepts ||= []
+      @accepts += types
+      @accepts
+    end
+
     # All graphql fields exposing an id, should expose a global id.
     def id
       GitlabSchema.id_from_object(object)
@@ -16,5 +22,13 @@ module Types
     def current_user
       context[:current_user]
     end
+
+    def self.assignable?(object)
+      assignable = accepts
+
+      return true if assignable.blank?
+
+      assignable.any? { |cls| object.is_a?(cls) }
+    end
   end
 end