From: Joel VanderWerf <vjoel@...>
Date: 2004-06-05T05:55:20+09:00
Subject: Re: Taming Test::Unit

Ben Giddings wrote:
> Recently I've been trying to use Ruby's Test::Unit framework to test a 
> network server.  When I do things a certain way, it works great.  It 
> runs all my tests and gives the expecte results.  However there are a 
> few things I don't understand how to do.
> 
> Right now, I have setup and teardown methods that make the TCP 
> connection to the server.  If these are simple like:
> 
>   def setup
>     @sock = TCPSocket.new($host, $port)
>   end
> 
>   def teardown
>     @sock.close
>   end
> 
> Then everything works.  However, I'd also like to be able to keep the 
> connection open while each test runs.  Each method I try to do this 
> fails, and I'm not quite sure why.
> 
> I first tried:
> 
>   def setup
>     if @sock.nil?
>       @sock = TCPSocket.new($host, $port)
>     end
>   end
> 
> And commenting out the teardown method, figuring that the socket would 
> be created only once, and that when the program exited it would take 
> care of closing the socket, but instead what happens is that the first 
> test works, but the for subsequent tests, @sock is nil, and because the 
> socket is never closed, TCPSocket.new fails with a connection refused 
> method.  Does anybody know why @sock would become nil?

IIRC, a new instance is created for each test_XXX method, and setup and 
teardown are called on that instance. So @sock is nil because setup was 
called on a different instance.

> I also tried defining an 'initialize' method to set up the socket at the 
> start of the test case, but evidently 'initialize' is used internally in 
> some sneaky way I don't understand.
> 
> So, could someone who understands the unit test framework better than me 
> explain how I can:
> 
> * Pass a hostname and port as commandline parameters to a script
> * Create a socket connected to that host/port
> * Run a series of tests using that socket
> * Disconnect the socket
> 
> Ideally, without using ugly things like global variables, etc.?

Class variables? I wish I had a better answer. Sometimes Test::Unit 
doesn't fit the testing patterns I want to use...