Override auto_migrate! and auto_upgrade!, to create the resources, if…

… DataMapper::Migrations is included in the model.

lib/dm-is-predefined/is/predefined.rb

@@ -6,8 +6,59 @@ module Predefined
       #
       # Fired when your plugin gets included into a Model.
       #
+      # @note
+      #   If the model already includes `DataMapper::Migrations`, then
+      #   {MigrationMethods} will be extended into the Model.
+      #
       def is_predefined
         extend DataMapper::Is::Predefined::ClassMethods
+
+        if defined?(DataMapper::Migrations) &&
+           included_modules.include?(DataMapper::Migrations)
+          extend MigrationMethods
+        end
+      end
+
+      module MigrationMethods
+        #
+        # Auto-migrates the model, then creates all predefined resources.
+        #
+        # @param [Symbol] repository_name
+        #   The repository to perform the migrations within.
+        #
+        # @return [true]
+        #
+        def auto_migrate!(repository_name=self.repository_name)
+          result = super(repository_name)
+
+          DataMapper.repository(repository_name) do
+            predefined_attributes.each_value do |attributes|
+              create(attributes)
+            end
+          end
+
+          return result
+        end
+
+        #
+        # Auto-upgrades the model, then creates any missing predefined resources.
+        #
+        # @param [Symbol] repository_name
+        #   The repository to perform the upgrade within.
+        #
+        # @return [true]
+        #
+        def auto_upgrade!(repository_name=self.repository_name)
+          result = super(repository_name)
+
+          DataMapper.repository(repository_name) do
+            predefined_attributes.each_value do |attributes|
+              first_or_create(attributes)
+            end
+          end
+
+          return result
+        end
       end
 
       module ClassMethods

spec/integration/predefined_spec.rb

@@ -1,11 +1,46 @@
 require 'spec_helper'
 require 'integration/models/test_model'
+require 'integration/models/migrated_model'
 
 describe DataMapper::Is::Predefined do
   before(:all) do
     TestModel.auto_migrate!
   end
 
+  context "migrations" do
+    it "should extend MigrationMethods, if Migrations are included" do
+      TestModel.should_not be_kind_of(DataMapper::Is::Predefined::MigrationMethods)
+      MigratedModel.should be_kind_of(DataMapper::Is::Predefined::MigrationMethods)
+    end
+
+    it "should create all predefined resources after auto_migrate!" do
+      MigratedModel.auto_migrate!
+
+      resources = MigratedModel.all
+
+      resources[0].id.should == 1
+      resources[0].name.should == 'test1'
+
+      resources[1].id.should == 2
+      resources[1].name.should == 'test2'
+    end
+
+    it "should create missing predefined resources after auto_upgrade!" do
+      MigratedModel.first(:name => 'test2').destroy!
+
+      MigratedModel.property :extra, String
+      MigratedModel.auto_upgrade!
+
+      resources = MigratedModel.all
+
+      resources[0].id.should == 1
+      resources[0].name.should == 'test1'
+
+      resources[1].id.should == 3
+      resources[1].name.should == 'test2'
+    end
+  end
+
   it "should define the @predefined_attributes instance variable" do
     TestModel.should be_instance_variable_defined(:@predefined_attributes)
   end