the ActionView::Helpers::TextHelper simple_format function for use outside Rails apps

simple_format.rb

require 'action_view'

NOTICE_ATTRIBS = 5
TOP_NOTICES = 5

# https://apidock.com/rails/v4.2.1/ActionView/Helpers/TextHelper/split_paragraphs
def split_paragraphs(text)
  return [] if text.blank?

  text.to_str.gsub(/\r\n?/, "\n").split(/\n\n+/).map! do |t|
    t.gsub!(/([^\n]\n)(?=[^\n])/, '\1<br />') || t
  end
end


# https://github.com/rails/rails/blob/0732ea7136da43cf3d84d8ce20dd7105a16e78b0/actionview/lib/action_view/helpers/text_helper.rb#L300
def simple_format(text, html_options = {}, options = {})
  obj = ActionView::Base.new
  wrapper_tag = options.fetch(:wrapper_tag, :p)

  text = obj.sanitize(text) if options.fetch(:sanitize, true)
  paragraphs = split_paragraphs(text)

  if paragraphs.empty?
    obj.content_tag(wrapper_tag, nil, html_options)
  else
    paragraphs.map! { |paragraph|
      obj.content_tag(wrapper_tag, obj.raw(paragraph), html_options)
    }.join("\n\n").html_safe
  end
end