slides.md

title	author	institute	aspectratio
But why does it work?	Rian McGuire	Melbourne Ruby 2023-08-30	169

Benefits

• Better understand your system, so it won't surprise you later

• Build confidence in dealing with unfamiliar problems
• Broaden your skills and learn about other parts of the stack
• Write better software

---

What's in this talk?

• Two live demos
  • Questions and interruptions encouraged
• Tips for exploring unfamilar code

---

Demo 1 - Magic Methods

class DemoController < ApplicationController
  schema :create do
    required(:name).value(:string)
  end

  def create
    if safe_params.failure?
      render status: 400, json: safe_params.errors
    else
      demo = Demo.create!(safe_params.to_h)
      render status: 201, json: demo
    end
  end
end

---

Demo 1 - Magic Methods

Rails.application.routes.draw do
  # Define your application routes per the DSL in
  # https://guides.rubyonrails.org/routing.html

  # Defines the root path route ("/")
  # root "articles#index"
  resources :demo
end

---

Demo 1 - Magic Methods

• Use method(:foo).source_location to find the code that defined a method
• A debugging tool like binding.break can help
• Use bundle open <gem> to locate gem code that's installed in your project

---

Demo 2 - The Ruby VM

• Sometimes the documentation is not enough

---

Demo 2 - The Ruby VM

def do_work(size)
    array = Array.new(size, 0)
    1_000_000.times do
        array.unshift(0)
        array.pop
    end
end

---

Demo 2 - The Ruby VM

• Search is your friend - use known strings like function names or error messages to find code

• If you're reading an unfamilar language or codebase, you don't have to understand everything at once

---

Conclusion

• The layers below are software, too

• Look for opportunities to improve your understanding

• Be curious

---

Thank you!