baisc.feature

Feature: Get

  In order to interact with the command line
  As an end user
  I want to see and enter things

  Scenario:
    Given I will see "Private?"
    Then I will enter "Yes, sir?"
    Then I will see "Jump"
    Then I will enter "Yes, sir"
    And I will see "Well done."
    And I run the script
    Then I should have jumped

colonel.rb

module Colonel
  class << self
    def inspect
      <<-END
        #{@actual_interactions.inspect}
        #{@expected_interactions.inspect}
      END
    end
    
    def interact(how, message)
      @expected_interactions << [ how, message ]
      @expected_interactions_by_type[how] << message
    end
    
    def activate!
      actual_interactions = []
      expected_interactions = []
      expected_interactions_by_type = {
        :see => [],
        :enter => []
      }
      interaction_index = 0
      gets_interaction_index = 0
      
      Kernel.module_eval <<-END
        alias :_puts :puts
        alias :_gets :gets
      END
      
      Kernel.send(:define_method, :gets) do
        actual_interactions << [:enter, expected_interactions_by_type[:enter][gets_interaction_index]]
        return actual_interactions.last
      end
      
      Kernel.send(:define_method, :puts) do |message|
        actual_interactions << [:see, message]
        if actual_interactions.last != expected_interactions[actual_interactions.size-1]
          raise <<-END
            Expected to see #{expected_interactions[actual_interactions.size-1]}
            But saw #{actual_interactions.last} instead.
            #{actual_interactions.size-1}
            #{actual_interactions.last}
            #{expected_interactions[actual_interactions.size-1]}
          END
        end
        message
      end
      
      Kernel.send(:define_method, :print) do |message|
        actual_interactions << [:see, message+"\n"]
        message + "\n"
      end
      
      @expected_interactions_by_type = expected_interactions_by_type
      @expected_interactions = expected_interactions
      @actual_interactions = actual_interactions
    end
    
    def deactivate!
      Kernel.module_eval <<-END
        alias :puts :_puts
        alias :gets :_gets
      END
      
      if @expected_interactions.size != @actual_interactions.size
        raise <<-END
        There were some unexpected interactions:
        #{inspect}
        END
      end
    end
  end
end

require 'rspec-expectations'
Before() do
  Colonel.activate!
end

After() do
  Colonel.deactivate!
end

using.steps

Then /^I should have jumped$/ do
  # ok, it worked. You'd put additional steps here normally.
end

When /^I run the script$/ do
  puts "Private?"
  gets
  puts "Jump"
end

Given /^I will see "([^"]*)"$/ do |words|
  Colonel.interact :see, words
end

Then /^I will enter "([^"]*)"$/ do |words|
  Colonel.interact :enter, words
end