Monkey patching in Ruby

My presentation at hcmc.rb meetup (hosted by Ruby Vietnam) on 25 Nov 2015

- What's monkey patching?
- The pros and cons of monkey patching.
- How to monkey-patch without making a mess.

Transcript

1. monkey_patching.in(:ruby) @huynhquancam
2. before(:talk) { about(:me) } Huỳnh Quán Cẩm. bug creator @ dadadee.com. die-hard Chelsea supporter. @huynhquancam | cam@hqc.me
3. [:monkey, :patching].sample 3.gigabytes + 1.megabyte 2.seconds.ago 'John Doe'.should have_content('John')
4. what.is?(:monkey_patching) The dynamic modifications of a class or module at runtime. * A common pattern shared across Ruby community.
5. ruby.class.is(:open)
6. the (:good) -> { side } extremely convenient, especially for hot-fix. shorter code writing. nicer DSL syntax.
7. The “beauty” of monkey-patching
8. But it’s just simply not worth it!
11. the -> (dark) { side } global namespace pollution. codes are more difficult to debug and understand. poor upgradeability. race condition of libraries. …
12. – lotusrb “zero monkey-patch of Ruby core and stdlib.”
13. but there are certain times that patching becomes unavoidable
14. when(monkey.patch).makes_sense the original libraries got a bug. stubbing a method for testing. …
15. MP.without { making.a(mess) } Fork the library on Github.
17. MP.without { making.a(mess) } Fork the library on Github. Put them into a module.
19. MP.without { making.a(mess) } Fork the library on Github. Put them into a module. Standardise the way of your monkey-patching files structure.
21. MP.without { making.a(mess) } Fork the library on Github. Put them into a module. Keep them together. Use Ruby refinements.
22. ruby 2.x and above
23. “Ruby is a beautiful language, don’t ruin it.”
24. THANK YOU!
25. questions.any?