Use generic type validator in new ci configuration

lib/gitlab/ci/config/node/configurable.rb

@@ -19,7 +19,7 @@ module Gitlab
 
           included do
             validations do
-              validates :config, hash: true
+              validates :config, type: Hash
             end
           end
 

lib/gitlab/ci/config/node/validators.rb

@@ -13,10 +13,13 @@ module Gitlab
             end
           end
 
-          class HashValidator < ActiveModel::EachValidator
+          class TypeValidator < ActiveModel::EachValidator
             def validate_each(record, attribute, value)
-              unless value.is_a?(Hash)
-                record.errors.add(attribute, 'should be a configuration entry hash')
+              type = options[:with]
+              raise unless type.is_a?(Class)
+
+              unless value.is_a?(type)
+                record.errors.add(attribute, "should be a #{type.name}")
               end
             end
           end

spec/lib/gitlab/ci/config/node/global_spec.rb

@@ -106,5 +106,11 @@ describe Gitlab::Ci::Config::Node::Global do
         expect(global).not_to be_valid
       end
     end
+
+    describe '#errors' do
+      it 'returns error about invalid type' do
+        expect(global.errors.first).to match /should be a hash/
+      end
+    end
   end
 end