poro.rb

class EnrollmentAcademicYearsCreator
  def initialize(enrollment, enrollment_academic_year_storage = EnrollmentAcademicYear)
    @enrollment = enrollment
    @enrollment_academic_year_storage = enrollment_academic_year_storage
  end

  def create
    enrollment_academic_year = @enrollment_academic_year_storage.create(
      :enrollment => @enrollment,
      :academic_year => @enrollment.academic_year,
      :turn => @enrollment.pre_enrollment_turn,
      :stage => @enrollment.pre_enrollment_stage,
    )
  end

  def self.create(enrollment)
    new(enrollment).create
  end
end

poro_spec.rb

require './poro'

describe EnrollmentAcademicYearsCreator do
  subject do
    EnrollmentAcademicYearsCreator
  end

  let :enrollment_storage do
    double('EnrollmentStorage')
  end

  it 'create blah bah' do
    enrollment = double('Enrollment', :pre_enrollment_turn => 1111, :academic_year => 2012, :pre_enrollment_stage => 'TheHell')
    enrollment_storage.should_receive(:create).with(:enrollment => enrollment, :academic_year => 2012, :turn => 1111, :stage => 'TheHell').and_return(true)

    subject.new(enrollment, enrollment_storage).create
  end
end