From: obscured by code <javierg1975@...>
Date: 2005-11-02T08:57:07+09:00
Subject: Re: <ANN> TeSLa, a Domain Specific Language for Unit Testing

Well, I think your confusion stems from my use of the word
"precondition". Thinking back, I realize it might have been better if
I'd have used a different wording.
In Eiffel a precondition is indeed (and I quote from Meyer's OOSC) "The
boolean expression which defines the domain", but in this thread I've
been using the word in the sense of:
"A condition that must exist or be established before something can
occur or be considered; a prerequisite."
The word 'requires' in the code is therefore not used in the sense of
the Eiffel keyword but rather to imply that what follows it is a
*requirement* for 'assert' to succeed. In plain English, the following
segment of code

test_method :add_item => [:item4] do
	requires {@items = [:item1, :item2, :item3]}
	assert {size == 4}
end

should be read as, "it is required for the 'items' property of any
Catalog instance to hold three items if the condition of 'size' being 4
is to be met after the method 'add_item' is called with an 'item' as
parameter".
All this leads me to think maybe a better syntax is, well... required
(no pun intended). Any suggestions regarding this will be very much
welcomed.
As an aside note, I've been reading Dave Astels' proposal of a Behavior
Driven approach (thanks James) and tend to agree with much of what he
proposes. Perhaps I could use some ideas (and syntax) from BDD to make
TeSLa more readable/intuitive. I'd still use Test::Unit underneath,
though, as maintaining tool integration is still very important to me.
Again, I'm very open to suggestions.