Help refactoring this nasty Ruby if/else statement

Question

So I have this big, hairy if/else statement. I pass a tracking number to it, and then it determines what type of tracking number it is.

How can I simplify this thing? Sp

Answer 1

Depending on whether or not the tracking code is a ruby object, you could also put helper's in it's class definition:

class TrackingCode < String 
  # not sure if this makes sense for your use case
  def ups?
    self[1,1] == 'Z'
  end
  def dhl?
    self[0,1] == 'Q'
  end
  def fedex?
    self.length == 22 && self[0, 2] == '96'
  end
  # etc...
end

Then your conditional becomes:

if number.ups?
  # ...
elsif number.dhl?
  # ...
elseif number.fedex?
end

One simplified conditional where you are operating on the implied feature of the tracking code. Likewise, if you were to take a looping approach, your loop would also be cleaner:

%w(ups? dhl? fedex?).each do |is_code|
  return if number.send(is_code)
end

or even:

%w(ups? dhl? fedex?).each do |is_code|
  yield if number.send(is_code)
end