How to unit-test exec_get/getter.call

unit-test-ruby

  
  class StrQ < Q
    attr_accessor :default
    
    def initialize(question, default = nil, io_source = STDIN, validator = nil) 
      @question = question
      @default = default    
      @io_source = io_source
      @validator = validator || lambda { true }
    end
    
    def exec 
      puts @question
      @answer = (io_source.gets || @default) while not @validator.call(@answer)
    end
	
	def answer
	  @answer || @default
	end
  end

## UNIT TEST:
require 'logirel/q_model'
require 'rspec'

RSpec.configure do |c|
  c.mock_with :rspec
end

describe Logirel::StrQ, "in its default mode of operation, when reading props" do
  before(:all) { @q = StrQ.new "Q??", "def" }
  subject { @q }
  it { should respond_to :question }
  it { should respond_to :default }
  specify { @q.answer.should eql("def") }
  specify { @q.question.should eql("Q??") }
end

describe Logirel::StrQ, "when feeding it OK input" do
  before(:all) do 
    @io = StringIO.new "My Answer"
	@validator = double('validator')
	@validator.should_receive(:call).once
	  with(an_instance_of(String))
	  and_return(true)
  end
  subject { StrQ.new("q?", "def", @io, @validator) }
  specify { subject.exec.should eql("My Answer") and subject.answer.should eql("My Answer") }
end

describe Logirel::StrQ, "when feeding it bad input" do
  before(:all) do 
    @io = StringIO.new "My Answer\nAnother Answer"
	
	@validator = double('validator')
	@validator.should_receive(:call).exactly(3).times.
	  with(an_instance_of(String))
	  and_return(false, false, true)
	  
  end
  subject { StrQ.new("q?", "def", @io, @validator) }
  specify { subject.exec }
end