module Cucumber::CoreExt::CallIn

def arity2
  arity == -1 ? 0 : arity
end

def call_in(obj, *args)
  obj.extend(mod)
  if self != StepMother::PENDING && args.length != arity2
    # We have to manually raise when the block has arity -1 (no pipes)
    raise ArityMismatchError.new("expected #{arity2} block argument(s), got #{args.length}")
  else
    obj.__send__(meth, *args)
  end
end

def file_colon_line
  path, line = *to_s.match(/[\d\w]+@(.*):(.*)>/)[1..2]
  path = File.expand_path(path)
  pwd = Dir.pwd
  path = path[pwd.length+1..-1]        
  "#{path}:#{line}"
end

def meth
  @meth ||= "__cucumber_#{object_id}"
end

def mod
  p = self
  m = meth
  @mod ||= Module.new do
    define_method(m, &p)
  end
end

def to_backtrace_line
  "#{file_colon_line}:in `#{name}'"
end

def to_comment_line
  "# #{file_colon_line}"
end