Question

I am working on an application that is about 250,000 lines of code. I’m currently the only developer working on this application that was originally built in .NET 1.1. Pervasive throughout is a class that inherits from CollectionBase. All database collections inherit from this class. I am considering refactoring to inherit from the generic collection List instead. Needless to say, Martin Fowler’s Refactoring book has no suggestions. Should I attempt this refactor? If so, what is the best way to tackle this refactor?

And yes, there are unit tests throughout, but no QA team.

Answer 1

250,000 Lines is alot to refactor, plus you should take into account several of the follow:

1. Do you have a QA department that will be able to QA the refactored code?
2. Do you have unit tests for the old code?
3. Is there a timeframe that is around the project, i.e. are you maintaining the code as users are finding bugs?

if you answered 1 and 2 no, I would first and foremost write unit tests for the existing code. Make them extensive and thorough. Once you have those in place, branch a version, and start refactoring. The unit tests should be able to help you refactor in the generics in correctly.

If 2 is yes, then just branch and start refactoring, relying on those unit tests.

A QA department would help a lot as well, since you can field them the new code to test.

And lastly, if clients/users are needing bugs fixed, fix them first.