Who Needs Test-Driven-Development?

This blog post was originally published on the ThoroughTest website, back when that was a thing. As a co-founder and primary content contributor for ThoroughTest, I absolutely own the rights to this post and the source code to which it refers. I intend to reproduce each blog post here on my personal blog since the company is no longer in business.

Recently, a seasoned developer asked a question of ThoroughTest that we wanted to answer for the community at-large: "Do really good developers need test-driven development?" The short answer is yes, absolutely, unequivocally, definitely. Unfortunately, that's not very convincing so we'll try to explain exactly why we feel that way.

First, let's address the elephant in the room on this one. ThoroughTest is a business and our business is training and certifying organizations and individuals on the concepts and processes of test-driven development. The short version is that we stand to make money when more people get on board with test-driven development. There's no getting around that. And although we want you to become a certified test-driven development practitioner with us, the truth is we feel passionately about helping people write quality software and we strongly believe that using test-driven development is one of the best ways to make that happen. Now that we've cleared that up, let's talk about why even really good developers need test-driven development.

If you are a really good developer and you don't work on a team of other developers and you always write your own requirements and you work for yourself at your own company and you don't care about realizing all the advantages of test-driven development then no, you don't need test-driven development. If, however, you live in the real world then the question isn't really about whether you as an individual need (or would benefit from) test-driven development. Test-driven development is an organization-wide effort that is most successful when everyone from the highest executive to the lowest intern is on board with it.

Organizational commitment aside, really good developers benefit from test-driven development just as much as brand new developers. We discussed five benefits of test-driven development in an earlier post and really good developers would still reap all of those benefits. Even if a really good developer already feels like she doesn't usually have problems understanding requirements, the process of discussing those requirements with the product owner in the context of how to test them will result in better communication between the developer, product owner, and even the QA team.

Since test-driven development isn't about making individual developers better, there's no point on the "good developer" scale where the benefits would be lost. One of the benefits of utilizing test-driven development that we didn't mention in our previous post was the stability of the code base going forward. As developers, we all know that there will almost definitely come a day when our beautiful, perfect, pristine code will have to be modified and we may not be the person who gets to make those modifications. By using test-driven development initially we'll be confident that future changes won't break what we've spent so much time creating, even if those future changes are made by a developer who is not "really good".

If you're considering making the transition to test-driven development, but you're not sure whether you personally would benefit from it, try to remember that this method of writing software is designed to benefit the entire team, division, and organization. So yes, even really good developers need test-driven development.