about.txt

How we're using Hydra's listener and messaging architecture to have each runner spin up a database after it boots. See also: http://github.com/ngauthier/hydra/wikis/multiple-test-databases

hydra.rake

require 'hydra'
require 'hydra/tasks'

Hydra::TestTask.new('hydra:specs') do |t|
  require 'hydra_extensions'

  t.verbose = !!ENV['VERBOSE']
  t.listeners << HydraExtensions::Listener::MultipleDatabases.new
  t.add_files 'spec/**/*_spec.rb'
end

Hydra::TestTask.new('hydra:features') do |t|
  require 'hydra_extensions'

  t.verbose = !!ENV['VERBOSE']
  t.listeners << HydraExtensions::Listener::MultipleDatabases.new
  t.autosort = false
  t.add_files 'features/activity_feeds/*.feature'
end

hydra_extensions.rb

require 'hydra_extensions/listener/multiple_databases'
require 'hydra_extensions/messages/master_messages'
require 'hydra_extensions/messages/worker_messages'

master_messages.rb

module HydraExtensions
  module Messages
    module Master
      class CreateDatabases < Hydra::Message
        def handle(worker)
          worker.runners.each do |runner|
            runner[:io].write(HydraExtensions::Messages::Worker::CreateDatabase.new)
          end
        end
      end

      class DropDatabases < Hydra::Message
        def handle(worker)
          worker.runners.each do |runner|
            runner[:io].write(HydraExtensions::Messages::Worker::DropDatabase.new)
          end
        end
      end
    end
  end
end

multiple_databases.rb

module HydraExtensions
  module Listener
    class MultipleDatabases < Hydra::Listener::Abstract
      def worker_begin(worker)
        worker[:io].write(HydraExtensions::Messages::Master::CreateDatabases.new)
      end

      # Fired before shutting down the worker
      def worker_end(worker)
        worker[:io].write(HydraExtensions::Messages::Master::DropDatabases.new) if worker[:io]
      end
    end
  end
end

worker_messages.rb

module HydraExtensions
  module Messages
    module Worker
      # Message telling the runner to create database.
      class CreateDatabase < Hydra::Message
        def handle(runner)
          ENV['TEST_ENV_NUMBER'] = "hydra_#{Process.pid}"

          schema_file = Rails.root.join('db','development_structure.sql')
          `/usr/local/mysql/bin/mysql -u root -f -e 'drop database if exists #{ENV['TEST_ENV_NUMBER']}'`
          `/usr/local/mysql/bin/mysqladmin -u root create #{ENV['TEST_ENV_NUMBER']}`
          `/usr/local/mysql/bin/mysql -u root #{ENV['TEST_ENV_NUMBER']} < #{schema_file}`
        end
      end

      class DropDatabase < Hydra::Message
        def handle(runner)
          `/usr/local/mysql/bin/mysqladmin -u root -f drop #{ENV['TEST_ENV_NUMBER']}`
        end
      end
    end
  end
end