BillTrost got a bee in his bonnet and wrote a UnitTest TestingFramework for the IconLanguage and a white paper for EaseSoftware. The white paper is at http://www.ease.com/company/whitepapers/trost-200212-IconUnit.htm -- go to the bottom of the paper for a reference to the framework itself.
As of April 2011, the paper is still present but the framework is gone. The paper makes it pretty clear how to implement the framework, though.
The abstract from Bill's paper is as follows:
This paper describes a unit testing framework for IconLanguage (http://www.cs.arizona.edu/icon/), a programming language with novel features such as expressions that may produce sequences of results and goal-directed evaluation. Most unit testing frameworks are written for object-oriented languages with exception handling mechanisms. By contrast, Icon is a procedural language whose unusual semantics make a straightforward implementation of a testing framework challenging. The testing framework uses Icon's sophisticated control flow facilities and its primitive preprocessor to create a functional, albeit aesthetically crude, unit testing framework.
Use, discuss, poke fun at!
-- BillTrost
BillTrost gave the Tuesday, March 4, 2000 Portland XP group talk. He volunteered to talk about his IconUnit UnitTest software. The talk is only about half an hour, so if anyone would like to hear about additional, related material, let Bill know.