TITLE: August 13 -- My Talk on Test-Driven Development AUTHOR: Eugene Wallingford DATE: August 17, 2004 2:07 PM DESC: skepticism about test-driven development ----- BODY: On the last day of SugarLoafPLoP 2004, I gave my test-driven development tutorial as the last event on the main program, just before the closing ceremony. I was pretty tired but brought as much energy as I could to it. The audience was tired, too, and it showed on their faces, but most folks were attentive and a couple asked interesting questions. One person asked about the role of traditional testing skills, such as finding equivalence classes on inputs, in TDD. These skills are still essential to writing a complete set of tests. Brian Marick and his colleagues in "agile testing" have written a lot about how testers work with agile projects. One of the great values of agile software development is that most everyone on your team can develop some level of expertise at writing tests, and can use whatever knowledge they learn about testing. Someone in industry asked whether TDD increases the quality of code but at the cost of longer development times. I answered that many believe TDD doesn't increase net development time, because this approach includes some testing time and because the increase in code quality means many fewer bugs to fix downstream. I could not point to any controlled experiments that confirm this, such as the ones Laurie Williams has condcuted on pair programming. If you know of any such studies, I would love to hear from you. I think this is an area ripe with possibilities. All in all, folks were skeptical, which is no surprise from an audience with a serious bent toward traditional software engineering practice. TDD and other agile practices are as disorienting to many folks as finding myself in the Sao Paulo airport was to me. Perhaps I helped them to see at least that TDD isn't irresponsible, that it can be a foundation for sound software development. This day turned into one like last Sunday -- after a half day of conference, Rossana Andrade took me and Paulo Masiero on a short sightseeing and souvenir-shopping trip around Fortaleza. Then she and her husband Richard took me to a cool Brazilian pizza place for dinner, and finally they took me to the airport a few hours before my 11:10 PM flight to Rio de Janeiro, the first leg of my journey home. The day became Saturday with no fanfare, just a long flight with a layover in Recife to exchange passengers and arrival in an empty and quite English-free Rio de Janeiro airport. I must say thanks to my hosts in Brazil, Paulo and Rossana. They took wonderful care of me, fed me lots of authentic food, told me all about their cities and country, chauffered me around, and translated everything from pizza menus to billboards for me. Indeed, all the folks at the conference were wonderful hosts and colleagues. I can heartily recommend SugarLoafPLoP to anyone interested in participating in a patterns conference. -----