This is a simple bit of code that I think is ugly. I am looking for a suggestion on making it more idiomatic. Thanks!

gistfile1.rb

  def populate_todolist
		progs = @user.participating_programs
		@to_do_list = progs.map { |prog| build_todolist_row(prog) }
		@to_do_list.compact!
	end

	# return nil if analysis yields no todolist row. compact! above removes the nil.
	def build_todolist_row prog
		rounds = prog.open_rounds
		raise "more than one round open in ToDoList" if rounds.length > 1
		if rounds.length == 1
			result = ToDoListRow.with(program_name: prog.name)
		end
		return nil
	end

@pitolas, i'm suggesting that it should be defined on programs, too. Or some method that encapsulates the notion of whether or not the program has more than one open round. Maybe the name isn't right; I don't know your domain.

I would change the API of these methods a little. Resulting in the following

def populate_todolist(programs)
  @to_do_list = programs.map do |program|
    build_todolist_row(program.name, program.open_rounds)
  end
end

def build_todolist_row(program_name, rounds)
  raise "more than one round open in ToDoList" if rounds.length > 1

  ToDoListRow.with(program_name: program_name)
end