Quickly generate a basic Sinatra application

sinatra_template.rb

require 'fileutils'
NAME = ARGV[0]
MODULE_NAME = NAME.gsub(/(?:^|_)(.)/) { $1.upcase }
ROOT = File.join(FileUtils.pwd, NAME)

def in_dir(dir)
  old_dir = FileUtils.pwd
  FileUtils.cd dir
  yield
  FileUtils.cd old_dir
end

def create_file(filename, content)
  puts "create #{filename}"
  path = File.join(ROOT, filename)
  FileUtils.mkdir_p File.dirname(path)
  File.open(path, 'w') do |f|
    f.write content
  end
end

create_file 'Gemfile', <<-EOS
source :rubygems
gem 'sinatra', require: 'sinatra/base'
gem 'bourbon'
gem 'sass'
gem 'haml'
gem 'coffee-script'
gem 'thin'

group :development do
  gem 'foreman'
  gem 'yard'
  gem 'rake'
end
EOS

create_file 'Procfile', <<-EOS
web: bundle exec rackup config.ru -p $PORT -s thin
EOS

create_file 'config.ru', <<-EOS
require 'rubygems'
require 'bundler'
Bundler.require

$:.unshift File.expand_path('../lib', __FILE__)
require '#{NAME}'
#{MODULE_NAME}::App.set :root, File.expand_path('..', __FILE__)
#{MODULE_NAME}::App.set :scss, load_paths: [
  File.join(Bundler.load.specs.find { |s| s.name == 'bourbon' }.full_gem_path, 'app', 'assets', 'stylesheets')
]
run #{MODULE_NAME}::App
EOS

create_file 'README', <<-EOS
#{MODULE_NAME}
EOS

create_file 'LICENSE', <<-EOS
Copyright (C) #{Time.now.year} #{`whoami`}

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
EOS

create_file '.env', 'PORT=3000'
create_file '.gitignore', '.env'
create_file "lib/#{NAME}.rb", <<-EOS
require '#{NAME}/app'
require '#{NAME}/version'

module #{MODULE_NAME}
end
EOS

create_file "lib/#{NAME}/version.rb", <<-EOS
module #{MODULE_NAME}
  VERSION = '0.0.0'
end
EOS

create_file "lib/#{NAME}/app.rb", <<-EOS
module #{MODULE_NAME}
  class App < Sinatra::Base
    set :haml, format: :html5
    set :scss, style: :compressed

    get '/styles.css' do
      headers 'Content-Type' => 'text/css; charset=utf-8'
      scss :styles
    end

    get '/lib.js' do
      headers 'Content-Type' => 'text/javascript'
      coffee :lib
    end

    get '/' do
      haml :index
    end
  end
end
EOS

create_file 'views/layout.haml', <<-EOS
!!! 5
%html{ lang: 'en' }
  %head
    %meta{ charset: 'utf-8' }
    %title #{MODULE_NAME}
    %link{ rel: 'stylesheet', href: '/styles.css' }
  %body
    #page
      = yield
    %script{ src: '/lib.js ' }
EOS

create_file 'views/styles.scss', "@import 'bourbon';"
create_file 'views/lib.coffee', ''
create_file 'views/index.haml', '%h1 Hello, world'

in_dir ROOT do
  system 'bundle install'
  system 'git init .'
  system 'git add .'
  system 'git commit -m "Initial commit"'
end