Pluck It: Extracting Micro-libraries into RubyGems

How many times have you written the same bits of code, over and over, and thought, “You know, if only this was big enough to be a gem, I would pluck it out." Often, we think of a RubyGem as a larger library of code that we “bolt on” to an app. And, these smaller code blobs become a hassle to distribute to the multiple apps that use them.

A small micro-library, done the right way, at the right time, can greatly improve an app.

But, when can you benefit from extracting a micro-library? And, how do you build and publish that code into a RubyGem? I'll go through the process, from A to Z.

Transcript

1. Pluck It Extracting micro-libraries and building rubygems @AdamCuppy
9. Add /lib/gravatar.rb
10. Moved from app/models/user.rb
15. Question:
16. Problem
17. https://rubygems.org/
18. “Pay no attention to the man behind the curtain!”
19. It’s a simple package: a self-contained collection of one or more files. rubygem:
20. http://bundler.io/
21. /path/to/myapp/Gemfile
22. $ bundle install
23. $ bundle install RubyGems
24. Bundler + RubyGems + MyApp
25. Bundler + RubyGems + MyApp RubyGems.org rails-4.2 rspec-core-3.2
26. Bundler + RubyGems + MyApp RubyGems.org rails-4.2 rspec-core-3.2 Private Gem Server priv_gem-1.0 priv_gem-1.0
27. App Bundle Bundler + RubyGems + MyApp RubyGems.org rails-4.2 rspec-core-3.2 Private Gem Server priv_gem-1.0 priv_gem-1.0
28. App Bundle $ bundle install Bundler + RubyGems + MyApp
31. $ bundle gem hash_diff ——test
32. $ bundle gem hash_diff ——test
33. $ bundle gem hash_diff ——test
34. $ bundle gem hash_diff ——test
35. $ bundle gem hash_diff ——test
36. $ bundle help gem
40. $ cd /path/to/my_gem $ bundle install $ rake
45. Build: $ cd /path/to/my_gem $ gem build hash_diff.gemspec
46. Publish: $ gem push hash_diff-0.1.0.gem
47. https://rubygems.org/gems/hash_diff
48. /path/to/myapp/Gemfile
49. $ cd /path/to/myapp $ bundle install
50. I’m Famous like @the_zenspider!
53. 1. Modify code 2. Increment VERSION constant 3. Rebuild gem 4. Publish new version 5. Update apps: $ cd /path/to/app; bundle update my_gem New Release
54. 1. Isolation from app code 2. Manage upgrades 3. Community support Pros…
55. Extraction encourages isolation; isolation encourages a simple interface; and, a simple interface is more maintainable.
56. 1. External dependencies to manage 2. Add’l development overhead 3. Community support Cons…
57. When is the “right time?”
58. It’s when the cost of maintaining an internal library, exceeds the cost of maintaining an external dependency.
59. https://rubygems.org/gems/trueman
60. https://rubygems.org/gems/gravasaurus_hex
61. https://rubygems.org/gems/hash_diff
62. http://guides.rubygems.org/
63. github.com/acuppy @adamcuppy
64. codingzeal.com @adamcuppy Adam Cuppy