rails--rails/activerecord/test/support/config.rb

require "yaml"
require "erb"
require "fileutils"
require "pathname"

module ARTest
  class << self
    def config
      @config ||= read_config
    end

    private

    def config_file
      Pathname.new(ENV["ARCONFIG"] || TEST_ROOT + "/config.yml")
    end

    def read_config
      unless config_file.exist?
        FileUtils.cp TEST_ROOT + "/config.example.yml", config_file
      end

      erb = ERB.new(config_file.read)
      expand_config(YAML.parse(erb.result(binding)).transform)
    end

    def expand_config(config)
      config["connections"].each do |adapter, connection|
        dbs = [["arunit", "activerecord_unittest"], ["arunit2", "activerecord_unittest2"],
               ["arunit_without_prepared_statements", "activerecord_unittest"]]
        dbs.each do |name, dbname|
          unless connection[name].is_a?(Hash)
            connection[name] = { "database" => connection[name] }
          end

          connection[name]["database"] ||= dbname
          connection[name]["adapter"]  ||= adapter
        end
      end

      config
    end
  end
end