extract-forum-to-aaa-engine.rb

NAME = "forum"
MODULE_NAME = "Forum"
PATH = "aaa/forum"

def run(cmd)
  puts cmd
  unless system(cmd)
    puts "Command failed"
    exit(-1)
  end
end

def write(path, content)
  puts "Writing #{path}"
  File.open(path, 'w') do |file|
    file.puts content
  end
end

def announce(txt)
  puts txt
end

announce "Move app dirs..."
Dir["app/*/#{NAME}"].each do |path|
  run "mkdir -p #{PATH}/#{path}"
  run "mv #{path}/* #{PATH}/#{path}"
end

announce "Move test dirs..."
Dir["test/*/#{NAME}"].each do |path|
  next if path.start_with?("test/fixtures")

  run "mkdir -p #{PATH}/#{path}"
  run "mv #{path}/* #{PATH}/#{path}"
end

announce "Move core model to lib"
run "mkdir -p #{PATH}/lib"
run "mv app/models/#{NAME}.rb #{PATH}/lib/"

announce "Fix core model"
GEM_RB = <<~RUBY
require "#{NAME}/engine"

#{File.read(PATH + "/lib/#{NAME}.rb")}
RUBY
write(PATH + "/lib/#{NAME}.rb", GEM_RB)

announce "Move app files..."
Dir["app/*/#{NAME}*"].each do |path|
  next if File.directory?(path)
  run "mkdir -p #{path.split('/')[0..-2].join('/')}"
  run "mv #{path} #{PATH}/#{path}"
end

announce "Move test files..."
Dir["test/*/#{NAME}*"].each do |path|
  next if File.directory?(path)
  run "mkdir -p #{path.split('/')[0..-2].join('/')}"
  run "mv #{path} #{PATH}/#{path}"
end

announce "Move migrations..."
run "mkdir -p #{PATH}/db/migrate"
run "mv db/migrate/*#{NAME}* #{PATH}/db/migrate"

announce "Add gem to Gemfile"
run %(echo "gem '#{NAME}', path: '#{PATH}'" >> Gemfile)

announce "Add test_helper"
File.open(File.join(PATH, "test", "test_helper.rb"), "w") do |f|
  f.puts 'require_relative "../../../test/test_helper"'
end

announce "Add engine.rb"
ENGINE_RB = <<~RUBY
  module #{MODULE_NAME}
    class Engine < ::Rails::Engine
      initializer :append_migrations do |app|
        append_engine_paths("db/migrate", app)
      end

      private

      def append_engine_paths(type, app)
        return if app.root.to_s.match root.to_s

        config.paths[type].expanded.each do |expanded_path|
          app.config.paths[type] << expanded_path
        end
      end
    end
  end
RUBY

run "mkdir -p #{[PATH, "lib", NAME].join('/')}"
write(File.join(PATH, "lib", NAME, "engine.rb"), ENGINE_RB)

announce "Add gemspec"
GEMSPEC = <<~RUBY
  $:.push File.expand_path("lib", __dir__)

  Gem::Specification.new do |spec|
    spec.name        = "#{NAME}"
    spec.version     = "0.0.1"
    spec.authors     = ["AAA"]
    spec.summary     = "The #{NAME} AAA Engine"
  end
RUBY

write(File.join(PATH, "#{NAME}.gemspec"), GEMSPEC)

puts <<STR
Done!

1. You now want to move the line `gem '#{NAME}'...` to the right spot.
2. Move config/routes/#{NAME} if any and update config/routes.rb to point to it
STR