A quick rails helper for creating bootstrap icons or fontawesome icons (v 2.3.2) It behaves as you would expect handling all HTML options.

bootstrap_icon.rb

#accepts array of string and symbols that will be prepended with 'icon-' 
#any hashes will be passed into the content tag call and any additonal classes will be merge into the content_tag class as well

def bootstrap_icon(*args)
    icon_words = []
    options = {}

    args.each do |arg|
      if arg.is_a?( String)  || arg.is_a?(Symbol) 
        icon_words << arg
      end
      if arg.is_a?( Hash )  
        options = options.merge arg 
      end
    end
    
    klasses = icon_words.map{|klass| "icon-#{klass}"}
    options = options.merge( { class: [ klasses , options[:class].to_s].join(" ")} )
    
    content_tag(:i, "", options)
  end