I don't know why I cant use rake -T or bundle exec rake -T

# app.rb

require 'rubygems'
require 'sinatra'
require "sinatra/activerecord"

class App < Sinatra::Base
 #configuraciones
 set :root, File.dirname(__FILE__)
 set :session_secret, 'super secret'
 set :public_folder, File.dirname(__FILE__) + '/public'
 set :layout, 'views/layouts'
 set :database, adapter: "sqlite3", database: "data"
 enable :sessions
 #before all requests
 before do
 headers['server'] = 'Ruby, Ubuntu'
 end
 #registro de helpers de la aplicacion
 helpers Sinatra::App::Helpers::Applicaction
 helpers Sinatra::App::Helpers::Filters
 #registro de helpers de routes
 helpers Sinatra::App::Helpers::ErrorHelper
 #registro de rutas
 register Sinatra::App::Routing::Home
 register Sinatra::App::Routing::Departamento
 register Sinatra::App::Routing::Provincia
 register Sinatra::App::Routing::Error
end

# Rakefile.rb

require 'sinatra'
require "sinatra/activerecord/rake"
require './app'

# config.ru

require_relative 'config/boot'
require File.dirname(__FILE__) + '/app'

run App

This the error message:

PS C:rubysinatra> bundle exec rake -T
WARNING: If you plan to load any of ActiveSupport's core extensions to Hash, be
sure to do so *before* loading Sinatra::Application or Sinatra::Base. If not,
you may disregard this warning.
rake aborted!
NameError: uninitialized constant Sinatra::App
C:/ruby/sinatra/app.rb:18:in `<class:App>'
C:/ruby/sinatra/app.rb:5:in `<top (required)>'
C:/ruby/sinatra/Rakefile.rb:4:in `<top (required)>'
(See full trace by running task with --trace)
PS C:rubysinatra>

And here is the file structure:

UPDATE

#First Change app.rb

helpers Sinatra::App::Helpers::Application

#This is de helpers.rb

 module Sinatra
 module App
 module Helpers
 module Application
 def load_css(csss)
 rpta = ''
 if defined? csss
 csss.each do |css|
 temp = '<link href="' + CONSTANTS[:static_url] + css + '.css" rel="stylesheet"/>'
 rpta = rpta + temp
 end
 end
 rpta
 end

 def load_js(jss)
 rpta = ''
 if defined? jss
 jss.each do |js|
 temp = '<script src="' + CONSTANTS[:static_url] + js + '.js" type="text/javascript"></script>'
 rpta = rpta + temp
 end
 end
 rpta
 end
 end
 end
 end
end

i have the same error

I SOLVE THAT I HAD TO ADD IN app.rb

require File.dirname(__FILE__) + '/config/initializers/helpers.rb'
require File.dirname(__FILE__) + '/config/initializers/filters.rb'
require File.dirname(__FILE__) + '/helpers/error_helper.rb'
require File.dirname(__FILE__) + '/routes/error.rb'
require File.dirname(__FILE__) + '/routes/home.rb'

but i dont know why my boot.rb doesnt work

config.ru

#!/usr/bin/env rackup
# encoding: utf-8

require_relative 'config/boot'
require File.dirname(__FILE__) + '/app'

run App

boot.rb

#registro de rutas
Dir["./routes/*.rb"].each 
#registro de initializers
Dir["./config/initializers/*.rb"].each 
#registro de modelos
Dir["./models/*_model.rb"].each 
#helpers
Dir["./helpers/*_helper.rb"].each