html_sanitizing.rb

require 'active_support'
require 'active_support/all'
require 'action_view'

array = ['a', 'b', 'http://www.example.com/?a=1', 'is a > 0 & a < 10?']
s = array.join(&:html_safe)
safe = array.join(''.html_safe + '').html_safe
safe_doubt = array.join(''.html_safe + '')
safe_sb = ActiveSupport::SafeBuffer.new(array.join)

# Only the next 2 methods are actually sanitizing the string and marking it as `html_safe`
include ActionView::Helpers
safe_sanitized = sanitize(array.join)

include ERB::Util
safe_h = h(array.join)

puts "s = #{s} is a SafeBuffer? #{s.is_a?(ActiveSupport::SafeBuffer)} Is html_safe? #{s.html_safe?}"

puts "safe = #{safe} is a SafeBuffer? #{safe.is_a?(ActiveSupport::SafeBuffer)} Is html_safe? #{safe.html_safe?}"

puts "safe_doubt = #{safe_doubt} is a SafeBuffer?"\
" #{safe_doubt.is_a?(ActiveSupport::SafeBuffer)} Is html_safe? #{safe_doubt.html_safe?}"

puts "safe_sb = #{safe_sb} is a SafeBuffer?"\
" #{safe_sb.is_a?(ActiveSupport::SafeBuffer)} Is html_safe? #{safe_sb.html_safe?}\n\n"

puts "safe_sanitized = #{safe_sanitized} is a SafeBuffer?"\
" #{safe_sanitized.is_a?(ActiveSupport::SafeBuffer)} Is html_safe? #{safe_sanitized.html_safe?}"

puts "safe_h = #{safe_h} is a SafeBuffer?"\
" #{safe_h.is_a?(ActiveSupport::SafeBuffer)} Is html_safe? #{safe_h.html_safe?}"