Boilerplate to test rake log:clear

rake_log_clear.rb

## Need help to run this file
# Steps followd 
# 1) cloned rails into /home/pramod/open_source/rails
# 2) added follwing 
#    require 'generators/generators_test_helper'
#    require 'rails/generators/rails/app/app_generator'
#    require 'env_helpers'
# 3) When I run `ruby rake_log_clear.rb` getting following Error  
#    log_clear.rb:22:in `require': cannot load such file -- generators/generators_test_helper (LoadError)

## Question: Is this correct way to test `rake log:clear`?
begin
  require 'bundler/inline'
rescue LoadError => e
  $stderr.puts 'Bundler version 1.10 or later is required. Please update your Bundler'
  raise e
end

gemfile(true) do
  source 'https://rubygems.org'
  # gem 'rails', github: 'rails/rails'
  gem 'rails', path: "/home/pramod/open_source/rails"
  gem 'arel', github: 'rails/arel'
  gem 'rack', github: 'rack/rack'
  gem 'sprockets', github: 'rails/sprockets'
  gem 'sprockets-rails', github: 'rails/sprockets-rails'
  gem 'sass-rails', github: 'rails/sass-rails'
end

require 'active_support'
require 'active_support/core_ext/object/blank'
require 'minitest/autorun'
require 'generators/generators_test_helper'
require 'rails/generators/rails/app/app_generator'
require 'env_helpers'

Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

class BugTest < Minitest::Test
  include GeneratorsTestHelper
  include EnvHelpers
  def truncates_custom_log_files
    f = File.open("./log/test.log", 'w')
    f.write("This will get truncated")
    f.close
    assert_called_with(generator, :run, ["rake log:clear"]) do
      action :rake, 'log:clear'
      data = File.read("./log/test.log")
      assert_empty data
    end
  end
end

Need help to run this file

Steps followd

1. cloned rails into /home/pramod/open_source/rails
2. added follwing
   require 'generators/generators_test_helper'
   require 'rails/generators/rails/app/app_generator'
   require 'env_helpers'
3. When I run ruby rake_log_clear.rb getting following Error

log_clear.rb:22:in `require': cannot load such file -- generators/generators_test_helper (LoadError)

Question: Is this correct way to test rake log:clear?