The myth of “correctness by design”

Now that you have a clearer picture of what I mean by effective and systematic software testing, let me debunk a myth. There is a perception among software developers that if you design code in a simple way, it will not have bugs, as if the secret of bug-free code is simplicity.

Empirical research in software engineering has repeatedly shown that simple, non-smelly code is less prone to defects than complex code (see, for example, the 2006 paper by Shatnawi and Li). However, simplicity is far from enough. It is naive to believe that testing can be fully replaced by simplicity. The same is true for “correctness by design”: designing your code well does not mean you avoid all possible bugs.