Gem provides helper method wrap_js_code that wraps javascript into <code></code> tags.
Add
gem 'js-code-wrapper'to your Gemfile.
wrap_js_code("<script>alert('wrap me!');</script>") # => "<code><script>alert('wrap me!');</script></code>"
wrap_js_code("<script>alert('wrap me!');</script>", :escape_js => true) # => "<script>alert('wrap me!');</script>"