1 files changed, 19 insertions, 10 deletions
diff --git a/lib/gitlab/ci/config/node/factory.rb b/lib/gitlab/ci/config/node/factory.rb
index 787ca006f5a..5919a283283 100644
--- a/lib/gitlab/ci/config/node/factory.rb
+++ b/lib/gitlab/ci/config/node/factory.rb
@@ -5,13 +5,11 @@ module Gitlab
         ##
         # Factory class responsible for fabricating node entry objects.
         #
-        # It uses Fluent Interface pattern to set all necessary attributes.
-        #
         class Factory
           class InvalidFactory < StandardError; end
 
-          def initialize(entry_class)
-            @entry_class = entry_class
+          def initialize(node)
+            @node = node
             @attributes = {}
           end
 
@@ -20,18 +18,29 @@ module Gitlab
             self
           end
 
-          def nullify!
-            @entry_class = Node::Null
-            self
-          end
-
           def create!
             raise InvalidFactory unless @attributes.has_key?(:value)
 
-            @entry_class.new(@attributes[:value]).tap do |entry|
+            fabricate.tap do |entry|
+              entry.key = @attributes[:key]
+              entry.parent = @attributes[:parent]
               entry.description = @attributes[:description]
             end
           end
+
+          private
+
+          def fabricate
+            ##
+            # We assume that unspecified entry is undefined.
+            # See issue #18775.
+            #
+            if @attributes[:value].nil?
+              Node::Undefined.new(@node)
+            else
+              @node.new(@attributes[:value])
+            end
+          end
         end
       end
     end