Faxtures (pronounced Facts-tures) are special fixture files that read, write, and COMPARE large outputs

faxtures.rb

module Faxtures
  module_function

  class Error < StandardError; end
  class ReadFileNotFound < Error; end

  # def read(*names, name, &block)
  #   TODO: read file line by line for RAM optimization
  # end

  # def write(*names, name, array, &block)
  #   TODO: yield blocks and write file line by line for RAM optimization
  # end

  def base_path
    TEST_ROOT
  end

  def read_lines(*names, name)
    dir = base_path.join('faxtures').join(*names)
    f = dir.join("#{name}.txt")

    unescape_array(f.readlines)
  rescue Errno::ENOENT => e
    raise ReadFileNotFound, e.message
  end

  def write_lines(*names, name, array)
    dir = base_path.join('faxtures').join(*names)
    f = dir.join("#{name}.txt")

    escaped_array = escape_array(array).join("\n")
    f.write(escaped_array)
    true
  rescue Errno::ENOENT => e
    OutputAdapter.block([e.class, e.message], :red)
    FileUtils.mkdir_p(dir)
    retry
  end

  def unescape_array(array)
    array.map { |s| s.strip.gsub('\n', "\n") }
  end

  def escape_array(array)
    array.map { |s| s.gsub("\n", '\n') }
  end

  module Syntax
    def assert_faxture(*names, name, lines)
      expected = read_faxture(*names, name)
      assert_equal expected, lines
    rescue Faxtures::ReadFileNotFound
      write_faxture(*names, name, lines)
      retry
    end

    def write_faxture(*args)
      Faxtures.write_lines(*args)
    end

    def read_faxture(*args)
      Faxtures.read_lines(*args)
    end
  end
end

ActiveSupport::TestCase.include Faxtures::Syntax