Testing-framework-aware Refactoring

Testing is the predominant way of establishing evidence that a program meets it requirements. When both test code and the application under test are written in the same programming language, a refactoring tool for this language should be able to refactor both application code and testing code together. However, testing frameworks normally come with particular programming idioms, such as their use of naming conventions, coding patterns, meta-programming techniques and the like. A refactoring tool needs to be aware of those programming idioms in order to refactor test code properly. Meanwhile the particularities of test code also suggest refactorings that are particularly applicable to test code. In this paper we present our experience of extending Wrangler, a refactoring tool for the Erlang programming language, so as to handle the three common testing frameworks for Erlang, as well as discussing the refactoring of test code in its own right.