Rails initializer tsort, dot digraph and png generation

initializers.sh

dot -o initializers.png -T png initializers.dot

initializers_dot.rb

# arrows will point to dependencies
File.open('initializers.dot', 'w') do |f|
  f.puts 'digraph initializers {'
  
  Rails.application.initializers.each do |initializer|
    if initializer.after
      f.puts %Q{  "#{initializer.name}" -> "#{initializer.after}"}
    end
    
    # print all node, even if unconnected
    unless initializer.after || initializer.before
      f.puts %Q{  "#{initializer.name}"}
    end
    
    if initializer.before
      f.puts %Q{  "#{initializer.before}" -> "#{initializer.name}"}
    end
  end
  
  f.puts '}'
end

initializers_tsort.rb

File.open('initializers.txt', 'w') do |f|
  Rails.application.initializers.tsort.each do |initializer|
    f.puts "#{initializer.name} from #{initializer.instance_variable_get(:@context).class.name}"
  end
end