I’m a big fan of what Cucumber has to offer a .NET developer like myself. What gets me down is the problem that IronRuby never seems *quite* mature enough to run it.

I’ve encountered (what i believe to be) a bug in IronRuby 0.9.0.0. The following feature (with no .NET interop) works using the Ruby interpreter, but fails under IronRuby.

The specification to reproduce the bug is based on a simple calculator performing an addition task. IronRuby barfs with the following error:

D:sourcerubycalculator>icucumber features
Feature: Addition
In order to save time
as a math n00b
I want to be able to add 2 numbers

wrong number of arguments (1 for 0) (ArgumentError)
c:/Ruby/lib/ruby/gems/1.8/gems/cucumber-0.3.94/bin/../lib/cucumber/ast/feature_element.rb:24:in `name_line_lengths’
:0:in `send’
IronRuby.Libraries:0:in `SendMessageOpt’
:0:in `each’
c:/Ruby/lib/ruby/gems/1.8/gems/cucumber-0.3.94/bin/../lib/cucumber/ast/feature_element.rb:20:in `first_line_length’
IronRuby.Libraries:0:in `Each’
:0:in `collect’

…
…

Hopefully the problem turns out to be something weird in my environment, but I’m reproducing the code below in case someone else would like to try it:

(i’ve also pushed it to Github: Ruby Calculator)

featuresaddition.feature

Feature: Addition
	In order to save time
	as a math n00b
	I want to be able to add 2 numbers

Scenario: Addition
	Given I have entered the first number 2 into the calculator
	And I have entered the second number 3 into the calculator
	When I call the add method
	Then the result 5 should be returned

Scenario Outline: More Addition
	Given I have entered the first number  into the calculator
	And I have entered the second number  into the calculator
	When I call the  method
	Then the result  should be returned

Examples:
	| x  | y | method | result |
	| 2  | 3 | add    | 5      |
	| 1  | 1 | add    | 2      |
	| 0  | 0 | add    | 0      |
	| -2 | 3 | add    | 1      |

featuresstep_definitionscalculator_steps.rb

require "spec"
require "lib/calculator"

Before do 
	@calc = Calculator.new
end

Given /^I have entered the first number (-?d+) into the calculator$/ do |n|
  @x = n.to_i
end

Given /^I have entered the second number (-?d+) into the calculator$/ do |n|
	@y = n.to_i
end

When /^I call the add method$/ do	
	@result = @calc.add(@x, @y)
end

Then /^the result (d+) should be returned$/ do |n|
  @result.should equal(n.to_i)
end

libcalculator.rb

class Calculator
	def add(x, y)
		return x+y
	end
end