Ruby

Notes

# with a !, it will be always be created
let!(:country_fr) { WorldCountry.by_name('France') }
# create only in this `describe` only if it's used in the test, like a lazy load
let(:place_of_birth_attributes) { PatientBases::PatientCascade::PLACE_OF_BIRTH_ATTRIBUTES }

• create method in the test is from engines/online_identity/test/factories/master_patient.rb, must come from a Gem factory_bot
  • The fields are created using test/factories/appointment.rb
• pundit_user: access control using pundit gem
  • some tests checks all controllers must have pundit_user, that’s why we set an empty object
• Dry::Validation is a gem that validates the inputs
• include AnotherClass keyword to get all the methods from AnotherClass
  • extend AnotherClass keyword will import all the static methods from AnotherClass
• def self.method == static VS def method specific to an instance
• pry instruction to automatically put a break point then open a rails console (REPL)
• variable&.method: the &. is a “Safe Navigation Operator”, it lets you call methods on objects without worrying that the object may be nil(Avoiding an undefined method for nil:NilClass error).
• method(&:symbol) is like static method call in java, .e.g Optional::get
• ::Namespace → tell ruby to go to the root folder, otherwise, it will think it’s in the same folder
• ArgumentError is the generic error to use instead of using a custom InvalidArgumentError exception
• include Validated is used more on active records “world”
• rails initializer
• use stdout flush to print directly

Resources

• Ruby Programming Language
• Pragmatic programmer

Tutorials

• Ruby Essentials - Techotopia
• Learn Ruby with the Edgecase Ruby Koans
• RubyMonk - Interactive Ruby tutorials
• DNS points to prohibited IP | tryruby.org | Cloudflare

Convention

Ruby Style Guide

Tools

Gems

Most of the libraries are distributed as a gem — a packaged library or application that can be installed with a tool called RubyGems.

• Where are gems installed?
  • We can check using gem env, on the INSTALLATION DIRECTORY, and GEM PATHS are the paths where it’s loading all the gems of the current environment.
  • src: https://stackoverflow.com/a/3408910/3612053
  • It does not seem to be able to “install” in a local folder…
• Difference between INSTALLATION DIRECTORY and USER INSTALLATION DIRECTORY:
  • The User Installation Directory (which has always existed) variable for RubyGems is the directory where gems will be installed when using the --user-install flag, which is a directory immediately within your home directory.
  • src: ruby on rails - What is “USER INSTALLATION DIRECTORY” in rubyGems env - Stack Overflow

# Generate a foobar.gem file
gem build
# Install a local gem globally
gem install foobar.gem
 
# Uninstall
gem uninstall foobar

Bundler

Bundler: The best way to manage a Ruby application’s gems

This tool allows you to manage your project dependencies and install exact gems and versions that are needed. These dependencies are specified in a Gemfile, which is placed in a project root directory.