class Cucumber::Messages::Helpers::NdjsonToMessageEnumerator

def extract_message(json_line)
  Envelope.from_json(json_line)
rescue StandardError
  raise "Not JSON: #{json_line.strip}"
end

def initialize(io)
  super() do |yielder|
    io.each_line do |line|
      next if line.strip.empty?
      message = extract_message(line)
      yielder.yield(message)
    end
  end
end