5 Rules - Test through module functions

test.rb

it "(when project is refunded)" do
  portfolio = portfolio_on(Date.new(2018, 2, 4))
  date = next_payment_date_for_project(
    portfolio,
    refunded_project,
    formatter: ->(date) { "My date: #{date}" },
    not_executed_message: "No se ha ejecutado",
    no_payments_left_message: "No hay más pagos",
    project_refunded_message: "No aplica"
  )
  
  expect(date).to eq "No aplica"
end

def next_payment_date_for_project(portfolio, project, options = {})
  portfolio.
    projects_with_investment.
    detect { |p| p.id == project.id }.
    next_payment_date(options)
end

def portfolio_on(current_date)
  portfolio_with([project_one, project_two, not_executed_project, refunded_project], current_date)
end

def portfolio_with(projects, current_date)
  projects_finder = FakeProjectFinder.new(*projects)
  UserPortfolio.portfolio_for_user(user, current_date, projects_finder)
end