RSpec failure formatter

failure_formatter.rb

# It will cycle N dots for progress.
# Failures are printed immediately in detail.
class FailureFormatter
  RSpec::Core::Formatters.register self, :example_passed, :example_failed, :dump_summary, :start_dump, :example_pending

  @@dot_count = 0
  N = 10

  attr_reader :output

  def initialize(output)
    @output = output || StringIO.new
    @example_group = nil
  end

  def example_passed(_notification)
    count_example('•', :green)
  end

  def example_pending(_notification)
    count_example('P', :pending)
  end

  def example_failed(notification)
    @@dot_count = 0
    clear_line

    output.puts RSpec::Core::Formatters::ConsoleCodes.wrap(notification.example.full_description, :failure)
    output.puts RSpec::Core::Formatters::ConsoleCodes.wrap(notification.example.location, :blue)

    if notification.example.exception.class == RSpec::Expectations::MultipleExpectationsNotMetError
      output.puts notification.example.exception.message
    else
      output.puts notification.example.exception
    end

    output.puts
    output.puts notification.colorized_formatted_backtrace
    output.puts
    output.puts
  end

  def start_dump(_notification)
    clear_line
    output.puts
  end

  def dump_summary(summary)
    output.puts RSpec::Core::Formatters::ConsoleCodes.wrap("=" * 100, :blue)
    output.puts summary.colorized_totals_line
    output.puts RSpec::Core::Formatters::ConsoleCodes.wrap("-" * 100, :blue)
    output.puts
  end

  private

  def count_example(t, c)
    clear_line
    @@dot_count += 1
    output.print RSpec::Core::Formatters::ConsoleCodes.wrap(t * @@dot_count.modulo(N), c)
  end

  def clear_line
    output.print "\e[2K\r"
  end
end