[Turnip] First hack to get line number and filename of feature

output.txt

Failures:

  1) Initialization Init and processing of schemes schemes until none left
     Failure/Error: execute_without_backtrace(*args, &block)
       expected 1 items, got 0
     # ./spec/acceptance/sessions.feature:75
     # spec/acceptance/steps/sessions_steps.rb:27:in `block (2 levels) in <top (required)>'
     # ./spec/support/turnip_hack.rb:64:in `execute_with_backtrace'
     # ./spec/support/turnip_hack.rb:31:in `block (6 levels) in run'
     # ./spec/support/turnip_hack.rb:28:in `each'
     # ./spec/support/turnip_hack.rb:28:in `block (5 levels) in run'

turnip_hack.rb

module Turnip
  def self.run(feature_file)
    Turnip::Builder.build(feature_file).features.each do |feature|

      describe feature.name, feature.metadata_hash do

        feature_tags = feature.active_tags.uniq

        feature.backgrounds.each do |background|

          before do
            background.steps.each do |step|
                # Hax here, add file_name
              step.file_name = feature_file.file_name
              Turnip::StepDefinition.execute(self, Turnip::StepModule.all_steps_for(*feature_tags), step)
            end
          end
        end
        feature.scenarios.each do |scenario|

          context scenario.metadata_hash do

            scenario_tags = (feature_tags + scenario.active_tags).uniq
            Turnip::StepModule.modules_for(*scenario_tags).each { |mod| include mod }

            it scenario.name do
              
              scenario.steps.each do |step|
                # Hax here, add file_name
                step.file_name = feature_file.file_name
                Turnip::StepDefinition.execute(self, Turnip::StepModule.all_steps_for(*scenario_tags), step)
              end
            end
          end
        end
      end
    end
  end
  
end

class Turnip::Builder
  # Hax here, add file_name and line accessor
  class Step    
    attr_reader :line, :file_name
    attr_writer :line, :file_name
  end
  
  def step(step)
    if step.doc_string
      extra_arg = step.doc_string.value
    elsif step.rows
      extra_arg = Turnip::Table.new(step.rows.map { |row| row.cells(&:value) })
    end
    # Hax here, add line number
    @current_step_context.steps << Step.new(step.name, extra_arg).tap { |s| s.line = step.line }
  end
end

class Turnip::StepDefinition
  class << self
    def execute_with_backtrace(*args, &block)
      begin
        execute_without_backtrace(*args, &block)
      rescue Exception => e
        e.backtrace.insert(3, "#{args[2].file_name}:#{args[2].line}")
        raise e
      end
      
    end
    # Ouch! alias_method_chain
    alias_method_chain :execute, :backtrace
  end
end