Creando la Estructura Inicial de la Gema

gem install bundler

Once you've installed Bundler, you should change directories to the location that you want to create your gem folder (for me, that location is ~/code/gems).

Once there you will create the gem like so:

bundle gem my_gem

Where my_gem is your gem's name. Note that if you are building a command line tool you should add the -b flag to this command (bundle gem my_gem -b).

You should see output that looks something like this:

      create  my_gem/Gemfile
      create  my_gem/Rakefile
      create  my_gem/.gitignore
      create  my_gem/my_gem.gemspec
      create  my_gem/lib/my_gem.rb
      create  my_gem/lib/my_gem/version.rb
Initializating git repo in /Users/mbleigh/code/gems/my_gem

Bundler has just generated a skeleton for your gem. You should recognize many of the files of the general structure of a gem.

Some of the nice things that Bundler has done for us include:

• .gitignore: There are certain files that you will not want to have to your git repository. Bundler automatically excludes the most common of these.

• version.rb: Bundler creates my_gem/lib/my_gem/version.rb automatically.

  This file is used as a single place to track the current version of your library.

  By default, Bundler sets the version to 0.0.1.

• Rakefile: The Rakefile created by Bundler is already set up with Bundler's gem helpers.

  These helpers allow you to release a new version of your gem (including creating a release tag in git and pushing the compiled gem to RubyGems) with a single command.

  $ rake -T
  rake build    # Build my_gem-0.0.1.gem into the pkg directory
  rake install  # Build and install my_gem-0.0.1.gem into system gems
  rake release  # Create tag v0.0.1 and build and push my_gem-0.0.1.gem to Rubygems
  rake spec     # Run RSpec code examples
  

  Estos son los contenidos del Rakefile:

  $ cat Rakefile 
  $:.unshift File.dirname(__FILE__) + 'lib'
  require "bundler/gem_tasks"
  
  require 'rspec/core/rake_task'
  RSpec::Core::RakeTask.new
  task :default => :spec
  

• Gemfile este es un ejemplo - ya modificado - del Gemfile generado:

  [~/srcLPPruby/building_gems/bleigh_tutorial_to_building_gems/my_gem(master)]$ cat Gemfile
  source 'https://rubygems.org'
  
  # Specify your gem's dependencies in my_gem.gemspec
  gemspec
  
  #gem 'guard'
  #gem 'guard-rspec'
  #gem 'guard-bundler'
  #gem 'rb-fsevent', '~> 0.9.1'
  

• gemspec

  $ cat -n my_gem.gemspec 
       1  # -*- encoding: utf-8 -*-
       2  lib = File.expand_path('../lib', __FILE__)
       3  $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
       4  require 'my_gem/version'
       5  
       6  Gem::Specification.new do |gem|
       7    gem.name          = "my_gem"
       8    gem.version       = MyGem::VERSION
       9    gem.authors       = ["John Smith"]
      10    gem.email         = ["some.name@pochomail.com"]
      11    gem.description   = %q{TODO: Write a gem description}
      12    gem.summary       = %q{TODO: Write a gem summary}
      13    gem.homepage      = ""
      14  
      15    gem.files         = `git ls-files`.split($/)
      16    gem.executables   = gem.files.grep(%r{^bin/}
                                ).map{ |f| File.basename(f) }
      17    gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
      18    gem.require_paths = ["lib"]
      19  
      20    gem.add_dependency 'sinatra'
      21    gem.add_development_dependency 'rspec', '~>2.11'
      22  end
  

• version.rb

  $ cat -n lib/my_gem/version.rb 
       1  module MyGem
       2    VERSION = "0.0.1"
       3  end