Rodrigo Walter Ehresmann rwehresmann

SOLID Principles with ruby examples

SRP - Single responsibility principle

A class should have only a single responsibility.

Every class should have a single responsibility, and that responsibility should be entirely encapsulated. All its services should be narrowly aligned with that responsibility, this embrace the high cohesion.

OCP - Open/closed principle

Software entities should be open for extension, but closed for modification.

Thoughts about Rails Presenters

This is a collection of links, examples and rants about Presenters/Decorators in Rails.

The "Decorator" pattern slowly started gaining popularity in Rails several years ago. It is not part of core Rails, and there's many different interpretations about how it should work in practice.

Jay Fields wrote about it in 2007 (before he switched back to Java and then Clojure): http://blog.jayfields.com/2007/03/rails-presenter-pattern.html

	# spec/system/support/login_helpers.rb
	# See this blog post for setup guide: https://evilmartians.com/chronicles/system-of-a-test-setting-up-end-to-end-rails-testing

	module LoginHelpers
	def login_as(user)
	# Craft session cookie to make request authenticated (to pass even routing constraints)
	# Compilation of these:
	# - https://dev.to/nejremeslnici/migrating-selenium-system-tests-to-cuprite-42ah#faster-signin-in-tests
	# - https://turriate.com/articles/2011/feb/how-to-generate-signed-rails-session-cookie
	# - https://github.com/rails/rails/blob/43e29f0f5d54294ed61c31ddecdf76c2e1a474f7/actionpack/test/dispatch/cookies_test.rb#L350

	# frozen_string_literal: true

	require "bundler/inline"

	gemfile(true) do
	source "https://rubygems.org"

	git_source(:github) { \|repo\| "https://github.com/#{repo}.git" }

	gem "rails", github: "rails/rails"

	# gem install multi_json json yajl-ruby oj benchmark-memory

	require 'multi_json'
	require 'json'
	require 'yajl'
	require 'oj'
	require 'benchmark'
	require 'benchmark-memory'

	hash1 = {

	#!/usr/bin/env bash
	# https://developers.supportbee.com/blog/setting-up-cucumber-to-run-with-Chrome-on-Linux/
	# https://gist.github.com/curtismcmullan/7be1a8c1c841a9d8db2c
	# https://stackoverflow.com/questions/10792403/how-do-i-get-chrome-working-with-selenium-using-php-webdriver
	# https://stackoverflow.com/questions/26133486/how-to-specify-binary-path-for-remote-chromedriver-in-codeception
	# https://stackoverflow.com/questions/40262682/how-to-run-selenium-3-x-with-chrome-driver-through-terminal
	# https://askubuntu.com/questions/760085/how-do-you-install-google-chrome-on-ubuntu-16-04

	# Versions
	CHROME_DRIVER_VERSION=`curl -sS https://chromedriver.storage.googleapis.com/LATEST_RELEASE`

	module JsonSerializer
	module_function

	#
	# Usage:
	# JsonSerializer.find_by_id(User, 1, only: [:id, :email, :address], except: [:address])
	#
	def find_by_id(klass, id, options = {})
	sql = "SELECT row_to_json(results) FROM (
	SELECT #{selected_attributes(klass, options)}

	aba_check_digit = (t) ->
	7 * (t[0] + t[3] + t[6]) +
	3 * (t[1] + t[4] + t[7]) +
	9 * (t[2] + t[5])

	aba_check_sum = (t) ->
	3 * (t[0] + t[3] + t[6]) +
	7 * (t[1] + t[4] + t[7]) +
	1 * (t[2] + t[5] + t[8])

	Plugboard = Hash[*('A'..'Z').to_a.sample(20)]
	Plugboard.merge!(Plugboard.invert)
	Plugboard.default_proc = proc { \|_, key\| key }

	def build_a_rotor
	Hash[('A'..'Z').zip(('A'..'Z').to_a.shuffle)]
	end

	ROTOR_1, ROTOR_2, ROTOR_3 = build_a_rotor, build_a_rotor, build_a_rotor