easy-going-rails/lib/formatters/basic_formatter.rb

# Opinioned Rails custom formatter
class BasicFormatter < SemanticLogger::Formatters::Color
  NAME_MAX_SIZE = 25
  CONTENT_PREFIX = '  '.freeze

  ANSI_DEBUG = "\e[90m".freeze
  ANSI_INFO = SemanticLogger::AnsiColors::GREEN
  ANSI_WARN = SemanticLogger::AnsiColors::YELLOW
  ANSI_ERROR = "\e[91m".freeze
  ANSI_NEUTRAL_INFO = SemanticLogger::AnsiColors::WHITE
  ANSI_REVERSED_WARNING = "\e[0;30;43m".freeze
  ANSI_REVERSED_ERROR = "\e[1;30;41m".freeze
  ANSI_REVERSED_FATAL = "\e[1;30;41m".freeze

  CONTENT_COLOR_MAP = ColorMap.new(
    debug: ANSI_DEBUG,
    info: ANSI_NEUTRAL_INFO,
    warn: ANSI_REVERSED_WARNING,
    error: ANSI_REVERSED_ERROR,
    fatal: ANSI_REVERSED_FATAL
  )

  EXCLUDE_LAMBDA = lambda { |log|
    if log.name == 'ActionView::Base'
      !log.message.starts_with?('  Rendering')
    elsif log.name == 'Rails' && !log.message.nil?
      log.message.exclude?('Started GET "/rails/live/reload')
    else
      true
    end
  }

  def initialize
    super(color_map: ColorMap.new(
      debug: ANSI_DEBUG,
      info: ANSI_INFO,
      warn: ANSI_WARN,
      error: ANSI_ERROR,
      fatal: ANSI_ERROR
    ))
  end

  def message
    return unless log.message

    message = log.message
    if log.name == 'Rails' && message.starts_with?('Completed')
      message.rstrip!
      message += "\n" unless message.starts_with?('Completed 5')
    end
    "#{CONTENT_PREFIX}#{CONTENT_COLOR_MAP[log.level]}#{message}#{color_map.clear}"
  end

  def level
    level = log.level == :info ? ' ' : log.level.to_s.chr.upcase
    "#{color}╣#{level}╠#{color_map.clear}"
  end

  def name
    "#{ANSI_DEBUG}#{log.name.truncate(NAME_MAX_SIZE).center(NAME_MAX_SIZE)}#{color_map.clear}"
  end

  def exception # rubocop:disable Metrics/AbcSize
    return unless log.exception

    root_path = Rails.root.to_s
    stack = log.exception.backtrace.select { |line| line.starts_with?(root_path) }
    stack = stack.map { |line| line.delete_prefix("#{root_path}/") }

    "#{CONTENT_PREFIX}#{ANSI_REVERSED_ERROR}#{log.exception.class}#{color_map.clear}: #{color}#{log.exception.message}#{color_map.clear}#{backtrace(stack)}" # rubocop:disable Layout/LineLength
  end

  def call(log, logger)
    self.color = color_map[log.level]
    self.log = log
    self.logger = logger
    [name, level, tags, named_tags, duration, message, payload, exception].compact.join(' ')
  end

  private

  def backtrace(stack)
    nil unless stack.count.positive?

    prefix = [name, level, tags, named_tags, duration, message, payload, CONTENT_PREFIX].compact.join(' ')
    "\n#{prefix}#{ANSI_ERROR}↳ #{stack.join("\n#{prefix}#{ANSI_ERROR}↳ ")}#{color_map.clear}"
  end
end