From: Iain Barnett <iainspeed@...>
Date: 2010-12-15T03:15:51+09:00
Subject: do your bit for my mental health - how to find the difference between two strings?

Hi,

I have a piece of code that doesn't work in a Sinatra app I've been writing that doesn't work.


These two forms don't work:

get '/tweets/:service/' do

  mymethod( params[:service] )
...

get '/tweets/:service/' do

  service = params[:service]
  mymethod( service )
...


This works:

get '/tweets/:service/' do

  mymethod( 'servicename' )

so does this:

get '/tweets/:service/' do

  service = 'servicename'
  mymethod( service )


Using the params[:service] variable then mymethod fails to do what I expect. If I hard-code the string that it's supposed to represent, it works. Every way I've examined this variable it looks exactly the same as a hard-coded version. Dump, inspect, to_s, length, class, equality, they all give the answer I expect - it's a String, and it is the same string that's in the URL that's been passed. I know that the method being called works, the only thing that doesn't is this variable. Nothing touches it before the method is called. I've tried via telnet too, no difference.

To help me keep the small grain of sanity I (hope to) have remaining, could anyone suggest a good way to find out what makes two strings different? 

I'm currently reading stuff on using the debugger, along with some stuff on Rack Test, but if anyone has a useful insight I can use I'd be very, very grateful. Would I best running a test through the debugger, for example?

Regards
Iain