output errors from logs for feature specs

feature_error_progress_formatter.rb

# spec/formatters/feature_error_progress_formatter.rb

require 'rspec/core/formatters/progress_formatter.rb'

class FeatureErrorProgressFormatter < RSpec::Core::Formatters::ProgressFormatter
  LINES_OF_CONTEXT = 15
  TEXT_TO_SEARCH = "Internal Server Error"
  FILE_TO_SEARCH = "log/test.log"

  private

  def dump_failure(example, index)
    super
    dump_log_error(example) if log_error_desired?(example)
  end

  def dump_log_error(example)
    log_error = attempt_to_fetch_log_error(example)
    if log_error.present?
      output_formatted_log_error(log_error)
    else
      output_unable_to_fetch
    end
  end

  def output_formatted_log_error(error)
    output.puts
    output.puts color("     Server error (from logs):", log_error_color)
    output.puts color("       #{error.gsub(/\e\[(\d+)m/, '').gsub("\n", "\n       ")}", log_error_color)
  end

  def log_error_desired?(example)
    example.exception &&
      example.metadata[:type] == :feature &&
      example.metadata[:js]
  end

  def attempt_to_fetch_log_error(example)
    command = log_fetching_commands(example)
    stdin, stdout, stderr = Open3.popen3 *command

    result = stdout.gets(nil)
    return nil unless result

    error_match = result.match(/(Internal Server Error.*)Ending: /m)
    if error_match
      error_match[1]
    else
      webmock_error_match = result.match(/(WebMock::NetConnectNotAllowedError.*)=========.*Ending: /m)
      webmock_error_match ? webmock_error_match[1] : nil
    end
  end

  def log_fetching_commands(example)
    trigger = "#{example.metadata[:file_path]}:#{example.metadata[:line_number]}"
    trigger += "-#{example.metadata[:execution_result][:started_at]}"
    starting = "Starting: '#{trigger}'"
    ending = "Ending: '#{trigger}'"

    starting = starting.gsub("/", "\\/")
    ending = ending.gsub("/", "\\/")

    regex = "/#{starting}/,/#{ending}/p"
    ["sed", "-n", "-e", regex, FILE_TO_SEARCH]
  end

  def log_error_color
    :blue
  end

  def output_unable_to_fetch
    output.puts
    output.puts color("     Unable to fetch errors from log.", log_error_color)
    output.puts
  end
end