

The importance of unit testing and functional testing - jasonlbaptiste
http://app.arat.us/blog/?p=159

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geebee
"Unit tests measure the quality of material used to build the application.
Functional tests measure the strength of the application structure. The
overall quality of the application is dependent on both."

I understand what the author is getting at with the bridge analogy, but I
think it's best to avoid analogies, especially in contentious arguments.
Otherwise, we'll end up in a battle of dueling analogies about bridges and
code - with each analogy containing the key assumption that either validates
or refutes the argument.

I'm not glad that there's "negativity about unit testing" either, but I am
glad that some people are starting to subject the 99% unit test coverage goal
to a cost/benefit analysis - and, yes, concluding at times that it isn't worth
it.

~~~
roder
It's interesting to think about the Cost Benefit analysis of testing. I can
say from my own personal experience that test driven development actually
speeds up my results and it seems that I get a test for free.

~~~
geebee
I agree - when unit testing is working well for me, it feels "free". I
realized I've always been "unit testing", in that my approach has usually been
to write a bit of code, test it with a short main(), write a bit more, and so
on. Unit testing, when it feels natural, is no different. I just keep the
tests instead of throwing them out. This is more of a parallel testing
approach than a TDD, but it seems to lead to good code coverage.

The part where I start to feel like the benefit isn't worth the cost is when I
feel like I'm unit testing a framework rather than my own code.

