From: Joel VanderWerf <vjoel@...>
Date: 2004-07-14T12:24:28+09:00
Subject: Re: instance variable question in test/unit TestCase

Nicholas Van Weerdenburg wrote:
> 1. A more general question: how do I initialize instance variables 
> without an "initialize" method? In my test case, I want instance 
> variables, but placing "@myvar=1" outside a method doesn't seem to work 
> ( I dimly recall that this is a class instance variable or something 
> like that). The reason I want to do this is that in subclassing 
> Test::Unit::TestCase I don't know offhand what it's initialize method 
> looks like (a no arg "initialize" gives an argment number error) and 
> don't want to learn just for this reason.
> 
> I just thought of trying the following-
> 
> def initialize *args
>    super *args
>    @myvar=1
> end
> 
> and it worked (I think). Cool.
> 
> My other option is the setup method, since that is called for before all 
> test methods. Are there any other options?

Use the ||= idiom. I like it because it can keep the initialization near 
the point of use.

def foo
   @myvar ||= 1 # initialize @myvar, but only if it's nil
end

Of course, this assumes that nil is not an expected value for the 
variable. Otherwise, you can use

   @myvar = 1 unless defined?(@myvar)

> 2. where do I find the will to return to programming in Java now that 
> I'm having so much fun in Ruby?

Dunno.. write a java code generator in ruby?