If unit testing is so great, why aren't more companies doing it? [closed]

Answer 1

Most tests don't test anything.
You write a fileopen() function and a unittest that fails if the file doesn't exist and succeeds if the file does exist. Great! Now did you check if it works with the filename in BIG5 chinese? on an NFS share? on vista with the file on a USB key and UAC turned ON?

The problem is that the unit tests are written by the same programmer who wrote the function, to the same set of assumptions and with the same level of skill. To really work the tests must be written by someone else, only to the published specs without them seeing the code. - In most companies just getting written specs would be a breakthrough!

Unit tests check for errors in the code of individual functions. They can work for data access layers, maths libraries etc where the inputs/outputs are well known and the internal structure is complex but for a lot of cases they are just a waste of time.
They fail when the errors are due to interactions between different parts of code or with the OS and the user. Problems like high/low DPI settings messing up a dialog box or a foreign language setting swapping a '.' and ',' aren't usually found.

Answer 2

There have been studies done on the ROI of unit tests - see this question.

Answer 3

Most companies are useless. Not the one that you (or I) work for, obviously.

Answer 4

There are plenty of companies out there that really do nothing along the lines of best practices. No code reviews, no unit testing, no testing plans, no nothing, just by the seat of their pants.

Take this as an opportunity to get them to use a Continuous Integration platform and develop unit tests! Easy way to impress the powers that be and increase the quality and stability of your code at the same time

Edit: As for reason, I think they just plain aren't aware of the current tools out there that make CI and unit testing extraordinarily easy.

Answer 5

Because unit tests are only usefull if you write testable code. And writing testable code is hard. And people are lazy and / or cheap.

EDIT : nuanced "lazy" as "lazy and / or cheap" ; some rare times, people actually have the skill and capacity and will to write tests, but they have something else to do that more directly affects the bottom line.

Answer 6

Unit testing is one of those black box terms that most people have heard, but don't know what exactly constitutes a unit test, where to start, how to write them, how to actually run tests, what exactly they should be testing, etc. etc. etc.

In a lot of cases, its easier for the unsure developer to simply dismiss them as unnecessary or some icing that only "enterprise level developers" need.