What do you think about the omnipresent "Test, Test, Test!" principle?

Question

In the old days programming used to involve less guesswork. I would write some lines of code and be 100% certain about what the code does and what it does not at a glance. Errors were mostly typos, but not about the functionality.

The last years I believe there is a trend for this "trial-and-error" programming : write the code (as if in draft), and then debug iteratively until the program's behavior appears to comply with the requirements. Test, and test again, and then again. Funny thing is, in my Visual Studio the "Run" button has been replaced by a button labelled "Debug" (= I know you have some bugs!). I have to admit that in several apps that I write I cannot guarantee a bug-free code.

What do you think ? Or maybe our systems are now overly complicated (browser/OS/Service Pack compatibilities, etc etc) and this justifies testing on all types of environments.

Answer 1

I've experienced the opposite, actually. Whereas it used to be a case of running until it worked, I now unit test until the tests pass... and this seems to be at least a reasonably common transition, as far as I can see.

I have to say that code which worked first time with only typos has never been the norm in my experience. The difference is that now I can find the problems much more quickly, and also spot if old problems come back. I can sometimes manage pretty short and simple bits of code with no errors (and posting on Stack Overflow has improved that ability) but large, complex systems? Heck no.

To answer the title of your post - the "test, test, test" principle is a good one, in my view... but I don't associate that with running the whole program repeatedly. I associate it with running unit tests frequently. I rarely need to use the debugger for unit tests - usually a failure makes the cause suitably obvious by inspection, because only a small amount of code is being tested.

Answer 2

The one word answer is "Complexity". The real answer is "Unnecessary Complexity"! The accounting principles has not changed for the past 30 years. Why then is writing an accounting system is so much more difficult today? It is good to have a Graphic User Interface but do we have to go overboard?

Software development has been caught in a vicious circle for many years. The complexity is feeding itself and instead of reducing it we simply hide it under layers and layers of wrappers. Eventually something is going to give.

When we favor form over function, we have to pay the price.