I am working on a web application with an existing code base that has probably been around for 10 years, there are ~1000 class files and ~100,000 lines of code. The good news is that the code is organized well, business logic is separate from the controller domain, and there is a high level of reusability. The bad news is there is only the very beginnings of a test suite (JUnit); there’s maybe 12 dozen tests at most.
The code is organized fairly typically for an enterprise Java project. There is a stuts-esque controller package, the model consists of almost purely data objects, there is a hibernate like database layer that is largely encapsulated within data access objects, and a handful of service packages that are simple, self contained, and logical. The end goal of building this test suite is to move towards a continuous integration development process.
- How would you go about building a test suite for such an application?
- What tools would you use to make the process simpler?
Any suggestions welcome. thanks!
Start by reading Working Effectively with Legacy Code (short version here). Next I would write a couple of end-to-end smoke tests to cover the most common use cases. Here are some ideas on how to approach it: http://simpleprogrammer.com/getting-up-to-bat-series/
Then when I need to change some part of the system, I would cover it with focused unit tests (refer to the aforementioned book) and then do the change. Little by little the system – or at least the parts which change the most often – would be better covered and working with it would become easier.