Roda App with sub applications

a.rb

class A < ::Roda
 def do_a_thing
  # ...
 end

 route do |r|
  r.get 'thing' do
   do_a_thing
  end
 end
end

app.rb

class App < ::Roda
 require './a'
 require './b'
 
 route do |r|
  r.on 'a' do
   r.run ::A
  end
  
  r.on 'b' do
   r.run ::B
  end
 end
end

b.rb

class B < ::Roda
 def do_b_stuff
  # ...
 end

 route do |r|
  r.get 'stuff' do
   do_b_stuff
 end
end