Tuesday, 6 December 2011

NOTE: Testing Macros - Parameters Revisited

As my planned series on testing drew to a close last week, I got an email from Quentin McMullen with some very kind words about the NOTE: blog, but also some very erudite comments about my choice of parameters for my testing macros. Rather than paraphrase Quentin's comments, I decided to publish his email verbatim (with his permission). Here's the heart of Quentin's email, followed by a few brief comments from me.
Just a quick thought:

I have a similar macro to %assert_condition, but it only has one (main) parameter, &CONDITION, instead of three; &LEFT &OPERATOR &RIGHT.  So it looks like:

%macro assert_condition(condition,tag=);
 if &CONDITION then
   put "TESTING: &sysmacroname: TAG=&tag, OUTCOME=PASS";
   put "TESTING: &sysmacroname: TAG=&tag, OUTCOME=FAIL";
%mend assert_condition;

So you can call it like:

%assert_condition(incount eq outcount)
%assert_condition (age > 0)
%assert_condition ( (incount=outcount) )

I tend to like the one parameter approach.

The only tricky part is if you have an equals sign in the condition, you have to put parentheses around the condition so the macro processor does not interpret the left side as a keyword parameter.  The nifty thing is that the parentheses also mask any commas,e.g.:

%assert_condition(gender IN ("M","F") )

Do you see benefits to the 3 parameter approach vs 1 parameter?
Yes, Quentin, I do very much see the benefits of your approach. Your example, using the IN operator, is particularly well chosen. Rest assured I'll be adapting the McMullen approach in future. Thanks for the comments. Keep reading NOTE:!