Back in November 2005 (yes, 2.5 years ago!) I wrote an article about how data types and type checking work in ActionScript. ActionScript is different than many languages, in that the ActionScript compiler can be used for compile-time type checking (or not), and at runtime it is a strongly typed language, but it also has features of dynamically typed languages. This allows for some flexibility but also means that you have to be careful about testing your code (because the compiler won’t always catch everything).
My conclusion (not original by any means) was that unit testing is an important tool for ActionScript developers. I’ve tried a couple of ActionScript unit testing frameworks (ASUnit and FlexUnit). And finally getting to the point of this post, I was interested to learn today that the crew at Digital Primates is releasing an open source unit testing framework for Flex, known as “dpunit”.