README.md

Usage

require tp_logger in spec_helper and run TPLogger.start The main goal of early start is to catch class definitions. Therefore it is important to start it before loading rails environment and initializers.

require 'tp_logger'
TPLogger.start(filter: 'project_folder_name', dump_path: 'tplogger.csv')

Then run rspec spec and wait. Specs will take a bit more time.

Finally all relations between classes will be dumped into CSV file, which can be converted to the DOT file using csv2dot.rb script.

ruby ./csv2dot.rb tplogger.csv tplogger.dot

csv2dot.rb

require 'csv'

csv = ARGV[0]
dot = ARGV[1]

g = File.open(dot, 'w')
g.puts 'strict digraph G{'

CSV.foreach(csv) do |from, method, to|
  g.puts %Q{"#{from}"->"#{to}" [label="#{method}"];}
end
g.print '}'

tp_logger.rb

class TPLogger
  class << self
    def start(filter: "", dump_path: "tplogger.csv")
      record_app_classes(filter)

      register_rspec_around_hook

      register_at_exit_hook(dump_path)
    end

    def relations
      @relations ||= Set.new
    end

    protected

    def register_rspec_around_hook
      RSpec.configure do |config|
        config.around(:each) do |example|
          logger = TPLogger.new

          logger.enable
          example.run
          logger.disable
        end
      end
    end

    def dump(dump_path)
      File.open(dump_path, 'w') do |csv|
        relations.each do |from, method, to|
          if app_class?(from) && app_class?(to)
            csv << [from, method, to].to_csv
          end
        end
      end
    end

    def register_at_exit_hook(dump_path)
      at_exit do
        TPLogger.dump(dump_path)
      end
    end

    def app_classes
      @app_classes ||= Set.new
    end

    def app_class?(klass)
      app_classes.include? klass
    end

    def record_app_classes(app_path)
      TracePoint.new(:end) do |tp|
        app_classes << tp.self if tp.path.match(app_path)
      end.enable
    end
  end





  def initialize
    @trace = TracePoint.new(:call, :return) do |tp|
      log_tp_event tp
    end
  end

  def relations
    self.class.relations
  end

  def enable
    @trace.enable
  end

  def disable
    @trace.disable
  end

  def chain
    @chain ||= []
  end

  def orig_class(tp)
    if tp.defined_class == ActiveRecord::Associations::CollectionProxy
      tp.defined_class
    else
      tp.self.class rescue tp.defined_class
    end
  end

  def log_tp_event(tp)
    tp.disable
    case tp.event
    when :call
      chain.push tp.method_id, orig_class(tp)

      if chain.size >= 4
        relation = chain.last(3)
        if relation.first != relation.last
          relations << relation
        end
      end
    when :return
      chain.pop(2)
    end
    tp.enable
  end
end