easy-going-rails/app/helpers/fa_icon_helper.rb

# Font Awesome Helper
module FaIconHelper
  LOGGER = SemanticLogger[Module.nesting[0]]
  ##
  # mandatory:
  #   name: without 'fa-' prefix
  #     might be a symbol, automatic conversion of undashed symbol
  #       for instance symbol :magnify_lens is converted to string 'magnify-lens'
  # optional:
  #   style: [:solid|:regular|:brands] solid as default value
  #   size: [2, 3, ..., 10 ]
  #   class: extra classes, any tailwind keyword...
  #   aria-hidden: true as default value
  #
  # example:
  #   fa_icon(:user)
  #   fa_icon(:user, style: :regular)
  #   fa_icon(:user, size: 2)
  #   fa_icon(:user, class: 'text-blue-500')
  ##
  def fa_icon(name, html_options = {})
    warn_useless_options html_options

    fa_icon = "fa-#{to_dash(name)}"
    fa_style = "fa-#{to_dash(html_options[:style] || :solid)}"
    fa_size = to_fa_size(html_options[:size])
    content_class = [fa_icon, fa_style, fa_size, html_options[:class]].compact.join(' ')
    tag.i(class: content_class, 'aria-hidden': html_options['aria-hidden'] || true)
  end

  private

  def to_dash(symbol) = symbol.to_s.dasherize

  def to_fa_size(value)
    return unless value

    size = value.to_i
    unless (1..10).include? size
      LOGGER.warn "unparseable size <#{value}>, should be an integer from a range of 1 to 10!",
                  Rails.backtrace_cleaner.clean(caller[1..])&.first
      return
    end
    return if size == 1

    "fa-#{size}x"
  end

  def warn_useless_options(hash)
    hash.except(:style, :size, :class, 'aria-hidden').each_key do |key|
      LOGGER.warn "useless option <#{key}>, please consider removal for safety reason!",
                  Rails.backtrace_cleaner.clean(caller[3..])&.first
    end
  end
end