Coding Challenge

_coding_challenge.md

Description

Imagine we have a book model and chapter model. Both models have attributes that needs to have sanitized html. We use a gem called sanitizer to sanitize the text. Now how would you refactor this code to be more DRY and scalable? Bonus: How would you test this?

Directions:

• Clone the gist
• Modify the code (change these files or add your own)
• Save your modifications as a forked gist
• Respond to the Breezy email with a link to your gist

book.rb

require 'sanitize_wrapper'
# The require statements can be moved to ApplicationRecord class if we need to perform this
# sanitization for every model that we have, but for the moment I prefer to explicitly load it
# in the models where it's needed.

class Book < ApplicationRecord
  attribute :about_the_book, :string
  
  before_validation SanitizeWrapper.new('about_the_book')
end

book_spec.rb

describe Book do
  subject { described_class.new(about_the_book: about_the_book) }
  
  context '#before_validation allows link tags for' do
    let(:about_the_book) { '<a href="#">Test</a>' }

    it 'about_the_book attribute' do
      expect(subject.about_the_book).to eq('<a href="#" rel="nofollow">Test</a>')
    end
  end

  context '#before_validation does not allow img tags for' do
    let(:about_the_book) { 'test <img src="test.jpg"/>' }

    it 'about_the_book attribute' do
      expect(subject.about_the_book).to eq('test')
    end
  end
end

chapter.rb

require 'sanitize_wrapper'

class Chapter < ApplicationRecord
  attribute :content, :string
  
  before_validation SanitizeWrapper.new('content')
end

chapter_spec.rb

describe Chapter do
  subject { described_class.new(content: content) }
  
  context '#before_validation allows link tags for' do
    let(:content) { '<a href="#">Test</a>' }

    it 'content attribute' do
      expect(subject.content).to eq('<a href="#" rel="nofollow">Test</a>')
    end
  end

  context '#before_validation does not allow img tags for' do
    let(:content) { 'test <img src="test.jpg"/>' }

    it 'content attribute' do
      expect(subject.content).to eq('test')
    end
  end
end

sanitize_wrapper.rb

# This is standart way of implementing callback object wrappers according to the Rails documentation
# http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html

require 'sanitize'

class SanitizeWrapper
  SANITIZE_CONFIG = Sanitize::Config::BASIC.merge output_encoding: "UTF-8"
  
  def initialize(attribute)
    @attribute = attribute
  end

  def before_validation(record)
    record.send("#{@attribute}=", Sanitize.fragment(record.send("#{@attribute}"), SANITIZE_CONFIG))
  end
end