Jeweler: Let us craft you the perfect gem
Rubygems are the awesome way of distributing your code to others. GitHub is the awesome way of managing the source code of your project. GitHub can even generate a Rubygem if you include a gemspec.
Trouble is when developing your Rubygems on GitHub, you generally do one of the following:
- Manage the gemspec by hand
- ... why bother doing something by hand when you can automate it?
- Write your own Rake stuff to create the Gem::Specification and output it to a gemspec file, and deal with keeping the Rakefile and gemspec in sync
- ... why keep reinventing the wheel?
- Use hoe or echoe for generating the gemspec
- ... why use utilities made for the days before GitHub existed?
- ... why have extra stuff you aren't going to use?
Jeweler was created with a few goals in mind:
- Only use a Gem::Specification as configuration
- Be one command away from version bumping and releasing
- Store version information in one place
- Only concern itself with git, gems, and versioning
- Not be a requirement for using your Rakefile (you just wouldn't be able to use its tasks)
- Use Jeweler internally. Oh the meta!
Run the following if you haven't already:
gem sources -a http://gems.github.com
Install the gem:
sudo gem install technicalpickles-jeweler
Configuration for an existing project
Armed with the gem, we can begin diving into an example. the-perfect-gem was setup as a Jeweler showcase, and a simple example:
begin require 'jeweler' Jeweler::Tasks.new do |s| s.name = "the-perfect-gem" s.summary = "TODO" s.email = "firstname.lastname@example.org" s.homepage = "http://github.com/technicalpickles/the-perfect-gem" s.description = "TODO" s.authors = ["Josh Nichols"] end rescue LoadError puts "Jeweler not available. Install it with: sudo gem install technicalpickles-jeweler -s http://gems.github.com" end
Here's a rundown of what's happening:
- Wrap everything in a begin block, and rescue from LoadError
- This lets us degrade gracefully if jeweler isn't installed
- Make a new
- It gets yielded a new
- This is where all the configuration happens
- Things you definitely need to specify:
- Things you probably want to specify:
- Things you can specify, but have defaults
files, defaults to
- Things you shouldn't specify:
version, because Jeweler takes care of this for you
- Other things of interest
executables, if you have any scripts
add_dependency, if you have any dependencies
- Keep in mind that this is a
Gem::Specification, so you can do whatever you would need to do to get your gem in shape
- It gets yielded a new
Bootstrap a new project
Before proceeding, take a minute to setup your git environment, specifically your name and email address:
$ git config --global user.email email@example.com $ git config --global user.name 'John Doe'
Jeweler provides a generator of sorts,
jeweler. It takes two arguments: your GitHub username and a repository name.
$ jeweler technicalpickles the-perfect-gem
Basically, this does:
- Creates the the-perfect-gem directory
- Seeds it with some basic files:
.gitignore, with the usual suspects predefined
Rakefile, setup with tasks for jeweler, test, rdoc, and rcov
README, with your project name
LICENSE, MIT, with your name prefilled
test/test_helper, setup with shoulda, mocha, and a re-opened
test/the_perfect_gem.rb, placeholder failing test
lib/the_perfect_gem.rb, placeholder library file
- Makes it a git repo
- Sets up
- Makes an initial commit, but does not push
At this point, you probably should create a repository by wandering to http://github.com/repositories/new. Be sure to use the same project name you told Jeweler.
With the repository firmly created, just push it:
$ git push origin master
You also probably should enable RubyGem creation for you repository: Go to your project's edit page and check the 'RubyGem' box.
Overview of Jeweler workflow
Here's the general idea:
- Hack, commit, hack, commit, etc, etc
- Version bump
- Have a delicious scotch
The hacking and the scotch are up to you, but Jeweler provides rake tasks for the rest.
Versioning information is stored in
VERSION.yml. It's a plain ol' YAML file which contains three things:
Consider, for a second,
- major = 1
- minor = 5
- patch = 3
Your first time
When you first start using Jeweler, there won't be a
VERSION.yml, so it'll assume 0.0.0.
If you need some arbitrary version, you can do one of the following:
rake version:write MAJOR=6 MINOR=0 PATCH=3
VERSION.ymlby hand (lame)
You have a few rake tasks for doing the version bump:
$ rake version:bump:patch # 1.5.1 -> 1.5.2 $ rake version:bump:minor # 1.5.1 -> 1.6.0 $ rake version:bump:major # 1.5.1 -> 2.0.0
If you need to do an arbitrary bump, use the same task you used to create
$ rake version:write MAJOR=6 MINOR=0 PATCH=3
The process of version bumping does a commit to your repo, so make sure your repo is in a clean state (ie nothing uncommitted).
It's pretty straight forward:
$ rake release
This takes care of:
- Generating a
.gemspecfor you project, with the version you just bumped to
- Commit and push the updated
- Create a tag
- Push the tag
Play the waiting game
How do you know when your gem is built? Has My Gem Built Yet was specifically designed to answer that question.
If it happens to be down, you can also check out the GitHub Gem repo's list. Just search for youname-yourrepo.s
Putting it all together
<hack, hack, hack, commit> $ rake version:bump:patch release
Now browse to http://gems.github.com/yourname/yourproject, and wait for it to be built.