[Pharo-dev] Tests around Pharo

As students of Master 2 IAGL from Lille 1 university (France), four of us are asked to develop some tests around an open-source project. Among proposed projects, we decided to contribute to Pharo. We'll have to develop 15-20tests (isolated/automated/reproducible/quick/good code coverage), and we are wanting them to be as much useful as possible for developers. Where (in the project) could it be useful to develop some tests ? Do you have advices/instructions for us in order to develop them ? We are new with Pharo and Smalltalk, and are having about 8-10hours available per developer. Best regards, Mathieu Schepens