create.rb

# Methods needed to create a project.

require 'rubygems'
require File.expand_path(File.dirname(__FILE__) + "/errors")

module Suspenders
  class Create
    attr_accessor :project_path

    def self.run!(project_path)
      creator = self.new(project_path)
      creator.create_project!
    end

    def initialize(project_path)
      self.project_path = project_path
      validate_project_path
      validate_project_name
    end

    def create_project!
      exec(<<-COMMAND)
        rails new #{project_path} \
          --template=#{template} \
          --skip-test-unit \
          --skip-prototype
      COMMAND
    end

    private

    def validate_project_name
      project_name = File.basename(project_path)
      unless project_name =~ /^[a-z0-9_]+$/
        raise InvalidInput.new("Project name must only contain [a-z0-9_]")
      end
    end

    def validate_project_path
      base_directory = Dir.pwd
      full_path = File.join(base_directory, project_path)

      # This is for the common case for the user's convenience; the race
      # condition can still occur.
      if File.exists?(full_path)
        raise InvalidInput.new("Project directory (#{project_path}) already exists")
      end
    end

    def template
      File.expand_path(File.dirname(__FILE__) + "/../template/suspenders.rb")
    end
  end
end