graph.rb

target_module = "ActionDispatch"
filepath = Rails.root.join("doc", target_module.tableize).to_s
ignore_classes = [Kernel, BasicObject]

Graph("G", "digraph") do
  classes = ObjectSpace.each_object(Class).select { |k| "#{k}".match /#{target_module}/ }

  global layout:'fdp'
  nodes style:'filled', colorscheme:'purd6'

  classes.each do |klass|
    tree, mods = klass.ancestors.select { |k| "#{k}".match /#{target_module}/ }.group_by { |anc| anc.is_a? Class }.map { |_, k| k.reverse }
    tree = tree.map.with_index { |k, i| [k, i] }

    if tree.count == 1
      node tree.first[0].to_id, label:tree.first[0]
    else
      tree.each_cons(2) do |(a, ai), (b, bi)|
        a_id, b_id = [a, b].map(&:to_id)
        route a_id => b_id
        node a_id, label:a
        node b_id, label:b
      end
    end

    mods = [] unless mods
    mods.each do |mod|
      mod_id = mod.to_id
      route mod_id => klass.to_id
      node mod_id, label:mod, shape:'box'
    end
  end

  save filepath, :png
end