How much unit testing is a good thing? [closed]

Answer 1

For unit testing, my company has adopted a fairly good strategy: we have a tiered application (Data Layer, Service Layer/Business Objects, Presentation layer).

Our service layer is the ONLY way to interact with the database (via methods in the data layer).

Our goal is to have at least a basic unit test in place for each method in the service layer.

It's worked well for us - we don't always thoroughly check every code path (especially in complex methods) but every method has it's most common code path(s) verified.

Our objects are not unit tested, except incidentally via the service layer tests. They also tend to be 'dumb' objects - most have no methods except those required (such as Equals() and GetHastCode()).

Answer 2

Start creating unit tests for the most problematic areas (ie sections of code that often breaks and causes a lot of communication between the sales team and developers). This will cause an immediate and visible impact by the sales team and other personnel.

Then once you have credibility and they see the value, start adding less problematic areas until you start to notice that the ROI just isn't there anymore.

Sure full coverage is nice in theory, but in practice it's often not necessary. Not to mention too costly.

Answer 3

The purpose of developer testing is to speed up the development of completed software of an acceptable level of quality.

Which leads to two caveats:

1. it is perfectly possible to do it wrong, so that it actually slows you down. So if you find it slows you down, it is very likely the case that you are doing it wrong.
2. your definition of 'acceptable quality' may differ from that of marketing. Ultimately, they are right, or at least have the final say.

Software that works is a specialised, niche market, equivalent to high-end engineered hardware made from specialist expensive materials. If you are outside that market, then customers will no more expect your software to work reliably than expect their shirt to stop a bullet.