A couple of weeks ago I wrote about typed assertions for Lazytest. Like so many things, it seemed like a good idea at the time. Define typed objects for each kind of assertion (e.g., equality, instanceof). When a test fails, throw an exception with one such object as the payload. The type of the object…
One of my stated goals with Lazytest was to enforce a clean separation between test assertions and code that runs before/around the assertions. The Spock framework for Java/Groovy calls these the stimulus and response, identified by the keywords when and then, respectively. I find this approach attractive, but one look at Spock’s documentation shows it’s…
Following my last post I integrated typed assertions into the master branch of Lazytest. This makes some changes to the API. Test examples in the it macro can no longer simply return true or false. Instead, they must call the expect macro. The Context type is gone, replaced by the Fixture protocol. More documentation to…
One thing clojure.test did reasonably well was tell you why an assertion failed. Currently, Lazytest fails in this regard. The problem with requiring test functions to return true/false to indicate pass/fail is that they can’t attach any additional information to a failure to explain why it failed. I realized that function return values are insufficient…
I have a curious obsession with testing frameworks. The first thing I do with any new programming language is try to write a test framework in it. It’s a useful exercise for exploring the metaprogramming facilities provided by any language. So in C, I use preprocessor macros; in Java, annotations; and in a Lisp, macros.…