Test-Driven Development in Clojure : An analysis of how differences between Clojure and Java affects unit testing and design patterns

Abstract: Agile methods and Test-Driven Development are well established methodologies within the software development industry. As a large part of today’s software development is done in Object-Oriented languages like Java it’s only natural that agile best practices have evolved to fit into the Object-Oriented paradigm. Clojure is a relatively young programming language that greatly differs from Object-Oriented languages and it’s thus not certain that these best practices can be directly applicable in Clojure development. This thesis attempts to identify key differences between Clojure and Java that may affect unit testing and the Test-Driven Development process. It finds that although the two languages are fundamentally the difference between them in regards to unit test creation and execution is small. The most striking consequence of Clojure’s lack of Object-Orientation is that dependency injection must be done between functions rather than between classes and objects. It’s also argued that the relative immaturity of the available Clojure development tools can have negative effects on the Test-Driven Development process.