RSpec Hell: run examples concurrently (using threads)

rspec-hell.rb

module RSpecHell
  def run_examples(reporter)
    return super unless metadata[:hell] && !(metadata[:parent_example_group] && metadata[:parent_example_group].key?(:hell))
    pool_size = ENV['HELL'].to_i

    q = Queue.new
    ordering_strategy.order(descendant_filtered_examples).each { |ex| q << ex }

    workers = []
    results = []
    pool_size.times do |n|
      workers << Thread.new do
        while (example = q.shift(true) rescue nil) do
          next if RSpec.world.wants_to_quit
          instance = new(example.inspect_output)
          set_ivars(instance, before_context_ivars)
          succeeded = example.run(instance, reporter)
          if !succeeded && reporter.fail_fast_limit_met?
            RSpec.world.wants_to_quit = true
          end
          results << succeeded
        end
      end
    end

    workers.each(&:join)
    children.clear
    results.all?
  end
end

if Nenv.hell?
  RSpec::Core::ExampleGroup.singleton_class.prepend(RSpecHell)
  p "Using RSpecHell 👿"
end