Close postgres open connections before running test suite

seqeul.rake

task 'db:test:prepare' => :close_postgres_connections
task :close_postgres_connections => :environment do
  #Kill any other open connections on the test db
  db_adapter =   defined?(::ActiveRecord::Base) ? ActiveRecord::Base.connection : nil
  db_adapter ||= defined?(::Sequel::Model)      ? ::Sequel::Model.db : nil

  if Rails.env.test? && db_adapter
    db_config = Rails.configuration.database_configuration[Rails.env].symbolize_keys

    begin
      #Will only work on Postgres > 8.4
      ::Sequel::Model.db.execute <<-SQL.gsub(/^\s{6}/,'')
      SELECT COUNT(pg_terminate_backend(procpid))
      FROM  pg_stat_activity
      WHERE datname = '#{db_config[:database]}';
      SQL
    rescue => e
      #Will raise an error as it kills existing process running this command
      #Seems to be only way to ensure *all* test connections are closed
    end
  end
end