C.1  Simplified Unit Testing

Testing your code is very important. Because of Sheerpower's extremely fast compile and link times (sub-second is typical), it is practical to add new code and test it every few lines of code written. Sheerpower also makes it practical to write the unit testing code at the same time.

Sheerpower makes unit testing quick and easy using just one statement and two directives:

• option test on -- enable test mode
• %test some_statement to compile only if in test mode
• %test_ignore some_statement to ignore if in test mode

option test on
%test print 'We are in test mode'
age = 15
%test age = 25
debug show age

Let's say there is an include file filled with testing code. You could conditionally compile and run that testing code by:

option test on
tax_rate = 6.5/100
%test %include 'safe_unit_tests.spinc'

Here is what safe_unit_tests.spinc looks like. Notice the use of the assert statement. You tell assert what is expected and it produces an exception if the assert fails:

// safe_unit_tests.spinc
print 'Testing the tax_rate of '; tax_rate
assert tax_rate > 0 and tax_rate <= 1.00, 'Tax rate is out of bounds'
print 'Tax rate is fine'

For clarity in your code, you can explicitly turn off test mode by:

option test off

By default, test mode is turned off.

Your code can contain any number of option test on or option test off statements. However, for easier code maintenance, just having one at the top of your program is best. Your code can also contain any number of %test and %test_ignore directives.