Consider seeing this code in a view. It seems a little long, and may be a candidate for refactoring.

= event.ticket.custom_message.to_s.strip.gsub("[URL]", site_url)

Attempt #1

One way to rewrite this is to make it as short as possible, ie, store all the complexity in a helper function.

= custom_message_for(event)

def custom_message_for(event)
  event.ticket.custom_message.to_s.strip.gsub("[URL]", site_url)
end

In my opinion, this isn’t really good because:

  • The complexity was simply moved from one part to another, instead of broken down into more easily-understandable chunks.
  • The method custom_message_for is too tightly coupled. To test this, you will need to create a mock event, with a mock ticket, with a mock custom message.

Attempt #2

I would prefer this to be written as:

= format_message(event.ticket.custom_message)

def format_message(message)
  message.to_s.strip.gsub("[URL]", site_url)
end

The view code may be a little longer, but you get these advantages:

  • The method format_message is simple and its purpose is immediately obvious.
  • Glancing at the view code (format_message(event...)), it’s apparent how the message is being derived.
  • It can be easily tested (just need to pass it a string).

…Another way to implement this is with a presenter, which may not be a bad idea either.