1 files changed, 61 insertions, 0 deletions
diff --git a/lib/gitlab/ci/config/node/configurable.rb b/lib/gitlab/ci/config/node/configurable.rb
new file mode 100644
index 00000000000..d60f87f3f94
--- /dev/null
+++ b/lib/gitlab/ci/config/node/configurable.rb
@@ -0,0 +1,61 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        ##
+        # This mixin is responsible for adding DSL, which purpose is to
+        # simplifly process of adding child nodes.
+        #
+        # This can be used only if parent node is a configuration entry that
+        # holds a hash as a configuration value, for example:
+        #
+        # job:
+        #   script: ...
+        #   artifacts: ...
+        #
+        module Configurable
+          extend ActiveSupport::Concern
+
+          def allowed_nodes
+            self.class.allowed_nodes || {}
+          end
+
+          private
+
+          def prevalidate!
+            unless @value.is_a?(Hash)
+              @errors << 'should be a configuration entry with hash value'
+            end
+          end
+
+          def create_node(key, factory)
+            factory.with(value: @value[key])
+            factory.nullify! unless @value.has_key?(key)
+            factory.create!
+          end
+
+          class_methods do
+            def allowed_nodes
+              Hash[@allowed_nodes.map { |key, factory| [key, factory.dup] }]
+            end
+
+            private
+
+            def allow_node(symbol, entry_class, metadata)
+              factory = Node::Factory.new(entry_class)
+                .with(description: metadata[:description])
+
+              define_method(symbol) do
+                raise Entry::InvalidError unless valid?
+
+                @nodes[symbol].try(:value)
+              end
+
+              (@allowed_nodes ||= {}).merge!(symbol => factory)
+            end
+          end
+        end
+      end
+    end
+  end
+end