# Strong encapsulation, static typing and unit testing **URL:** \ **Category:** Ruby\ **Created:** [December 29, 2006, 11:46pm UTC](https://www.ruby-forum.com/t/strong-encapsulation-static-typing-and-unit-testing/80689 "2006-12-29T23:46:14Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![npenkov](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ee59a6/32.png) [@npenkov](https://www.ruby-forum.com/u/npenkov)\ **Post date:** [December 29, 2006, 11:46pm UTC](https://www.ruby-forum.com/t/strong-encapsulation-static-typing-and-unit-testing/80689/1 "2006-12-29T23:46:14Z")
Hi Everyone, I’ve been following the discussion on strong encapsulation with interest… It’s a really interesting topic. Reading through the posts and some of the Ruby books and documentation, I’ve come across the idea that Ruby’s lack of strong typing is less important because there is some support for a unit testing framework. My attention was grabbed by Jeff’s response in the original thread, so instead of hijacking it, I thought it might be interesting to start a new discussion. I thought I’d kick things off with these points, sort of in order of priority: Software engineering o In our experience, putting well defined layers into the code has always helped clarify the system o You can never tell what your users are going to do with your code! More protection is usually better 🙂 o Clarity and reliability are almost always more important than speed Testing in the real world o Very often, only superficial testing is done, and this only catches the trivial stuff o It’s easy to catch the easy errors. To catch the hard ones takes a _lot_ of work o The late-breaking bugs are the ones that hurt - especially if it’s a silly typo that could have been caught statically Unit testing o Often the problems crop up in integration rather than within a particular unit - having stricter checking on interfaces would really help o It’s hard to push a unit into all corners of it’s functionality without reasonably fully fledged supporting functionality o If the testbench suffers from the same limitations as the language it’s testing, how do you know where the error’s being generated? Testing methodology o There’s a difference between syntax checking and verification of functional correctness o Rigorous testing of software is often extremely hard to do, if not impossible - esp GUIs and large web apps o Strict type checking can really help with the readability and maintainability of code Just so you know where I’m coming from, I work verifying functional correctness of CPUs and designing the supporting tool flows. I have a strong disposition towards strong encapsulation, typing and testing, and even then I never do enough testing! What do you all think? Cheers, Nick – Nick P. removed\_email\_address@domain.invalid ---
**Author:** ![npenkov](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ee59a6/32.png) [@npenkov](https://www.ruby-forum.com/u/npenkov)\ **Post date:** [December 30, 2006, 3:22am UTC](https://www.ruby-forum.com/t/strong-encapsulation-static-typing-and-unit-testing/80689/2 "2006-12-30T03:22:52Z")
Nick P. wrote: > My attention was grabbed by Jeff’s response in the original thread, so > > particular unit - having stricter checking on interfaces would really > impossible - esp GUIs and large web apps > Cheers, Well … this discussion comes up often enough on this list that most peoples’ opinions are well known, and usually repeat discussions that have been going on since the dawn of time – I can imagine Euclid and Pythagoras, at least, discussing their branches of mathematical reasoning with their colleagues in similar fashion. 🙂 But here goes: 1. One thing I _haven’t_ seen in any of these discussions is the “gas law models” of large software engineering projects. I can’t seem to find any references on the web, but the books of Lawrence Putnam are a good place to start. 2. As I (and IIRC others) have mentioned in these discussions, the one language that was deliberately designed to facilitate development and maintenance of large software projects – Ada – seems to be a well-kept secret. It’s still very much a live language – GNU has a compiler, for example – but, given that it was specifically designed to facilitate large efforts, how come the large efforts are being done in Java for the most part? 3. The practices and processes of software engineering in most cases need to be _subordinate_ to the business model, even (especially) when the business is a software development business! In many cases, that means you have to ship something that’s “good enough” rather than something that’s provably correct and has no transactions with unacceptable response times. – M. Edward (Ed) Borasky, FBG, AB, PTA, PGS, MS, MNLP, NST, ACMC(P) [http://borasky-research.blogspot.com/](http://borasky-research.blogspot.com/) If God had meant for carrots to be eaten cooked, He would have given rabbits fire. ---
**Author:** ![npenkov](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ee59a6/32.png) [@npenkov](https://www.ruby-forum.com/u/npenkov)\ **Post date:** [December 30, 2006, 9:43am UTC](https://www.ruby-forum.com/t/strong-encapsulation-static-typing-and-unit-testing/80689/3 "2006-12-30T09:43:23Z")
On 12/30/06, M. Edward (Ed) Borasky [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Nick P. wrote: > > Well … this discussion comes up often enough on this list that most > peoples’ opinions are well known, I do hope they change, do you not? I have the feeling that each line of code I write change my attitude towwards programming. Maybe I am desperately missing to work in large scale projects ☹ and usually repeat discussions that > have been going on since the dawn of time – I can imagine Euclid and > Pythagoras, at least, discussing their branches of mathematical > reasoning with their colleagues in similar fashion. 🙂 As a matter of fact I did 😉 But here goes: > example – but, given that it was specifically designed to facilitate > large efforts, how come the large efforts are being done in Java for the > most part? If I only knew? we lost our Ada83 project in 89 and I never could find an Ada job anymore, I do not even know Ada95 save for a most superficial layer. 1. The practices and processes of software engineering in most cases > need to be _subordinate_ to the business model, even (especially) when > the business is a software development business! In many cases, that > means you have to ship something that’s “good enough” rather than > something that’s provably correct and has no transactions with > unacceptable response times. Could you elaborate? Would that pragmatical approach not allow to implement using _your_ technique? Please note I am out off business since 89, have to earn my bread with IP/DB/OS (baaad!) – > M. Edward (Ed) Borasky, FBG, AB, PTA, PGS, MS, MNLP, NST, ACMC(P) > [http://borasky-research.blogspot.com/](http://borasky-research.blogspot.com/) > > If God had meant for carrots to be eaten cooked, He would have given > rabbits fire. > > Cheers > Robert – “The real romance is out ahead and yet to come. The computer revolution hasn’t started yet. Don’t be misled by the enormous flow of money into bad defacto standards for unsophisticated buyers using poor adaptations of incomplete ideas.” - Alan Kay ---
**Author:** ![npenkov](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ee59a6/32.png) [@npenkov](https://www.ruby-forum.com/u/npenkov)\ **Post date:** [December 30, 2006, 11:05pm UTC](https://www.ruby-forum.com/t/strong-encapsulation-static-typing-and-unit-testing/80689/4 "2006-12-30T23:05:31Z")
Robert D. wrote: > On 12/30/06, M. Edward (Ed) Borasky [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > Nick P. wrote: > > > > Well … this discussion comes up often enough on this list that most > > peoples’ opinions are well known, > > I do hope they change, do you not? > Of course … times change, people change, the only constant is change, > etc. But there are evolutions and revolutions, steady growth as well as > bubbles and crashes, and lots of other phenomena in complex adaptive > systems. I don’t view Ruby as a revolution, for example – certainly > FORTRAN, COBOL, Lisp and Smalltalk were revolutions and possibly even > Perl. > I have the feeling that each line of code I write change my attitude > towwards programming. > Ah, to be young again! 🙂 The last time I had that feeling was when I > got my first Lisp program to run successfully. 🙂 > Maybe I am desperately missing to work in large scale projects ☹ > It’s an acquired taste, for sure. 🙂 > If I only knew? we lost our Ada83 project in 89 and I never could find an > Ada job anymore, I do not even know Ada95 save for a most superficial > layer. > Well, in terms of complex adaptive systems, Ada got forced into a niche > somehow. A while back, when VAXes ruled the world, Intel actually > designed a 32-bit chip (IIRC their first 32-bit chip) specifically for > Ada. Just as today’s programmers prefer the freedom of > Perl/Python/PHP/Ruby over Java and C++, the programmers back then > preferred the freedom of Fortran and C. There are still Ada jobs, I think. Somebody must at least be maintaining all the Ada code that got written when it was mandated as the implementation language for defense projects. And I think there are even a few open source projects written in Ada. > implement using _your_ technique? Please note I am out off business > since > 89, have to earn my bread with IP/DB/OS (baaad!) > Well … I can elaborate at great length, but I suspect I’d simply be > repeating what other people have said and said more eloquently. This > particular discussion is centered on language features and software > engineering practices, and the original poster was very explicit about > at least the business _context_ of his post, if not the actual business > model. In short, what works for him might not work for someone building, > say, a social web site, an algorithmic composition package or a queuing > theory model. – M. Edward (Ed) Borasky, FBG, AB, PTA, PGS, MS, MNLP, NST, ACMC(P) [http://borasky-research.blogspot.com/](http://borasky-research.blogspot.com/) If God had meant for carrots to be eaten cooked, He would have given rabbits fire. ---
**Author:** ![npenkov](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ee59a6/32.png) [@npenkov](https://www.ruby-forum.com/u/npenkov)\ **Post date:** [December 31, 2006, 6:57pm UTC](https://www.ruby-forum.com/t/strong-encapsulation-static-typing-and-unit-testing/80689/5 "2006-12-31T18:57:05Z")
Robert D. wrote: > What I meant is the following, Is it possible to hide the choice of the > implementation language from the customer, can an abstraction be made to > “get the job done”. > But this still might be OT, do not mind too much about it. > Now _that_ is an interesting philosophical question. Not “is it wise to > hide the choice of the implementation language from the customer”, but > is it _possible_? On an “agile” project, probably it is neither wise nor possible, given that the customer is probably in the loop and even in the room while the programming is going on. But on a huge project, unless the language is mandated, like Ada for certain types of defense projects, it’s not only possible but probably a good idea. I have, for example, absolutely no idea what the implementation language is for any of the major Microsoft projects – Office, the Windows kernel, or IE. I can guess it’s C++, or I could Google for it, I suppose, and given the age of the products I can rule out Java. But there’s nothing in any of these complex products that is customer-visible that rules out implementation in any sufficiently-capable language. – M. Edward (Ed) Borasky, FBG, AB, PTA, PGS, MS, MNLP, NST, ACMC(P) [http://borasky-research.blogspot.com/](http://borasky-research.blogspot.com/) If God had meant for carrots to be eaten cooked, He would have given rabbits fire. ---
**Author:** ![npenkov](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ee59a6/32.png) [@npenkov](https://www.ruby-forum.com/u/npenkov)\ **Post date:** [January 1, 2007, 12:01pm UTC](https://www.ruby-forum.com/t/strong-encapsulation-static-typing-and-unit-testing/80689/6 "2007-01-01T12:01:05Z")
On 12/31/06, M. Edward (Ed) Borasky [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > On an “agile” project, probably it is neither wise nor possible, given > that the customer is probably in the loop and even in the room while the > programming is going on. But on a huge project, unless the language is > mandated, like Ada for certain types of defense projects, it’s not only > possible but probably a good idea. I have, for example, absolutely no > idea what the implementation language is for any of the major Microsoft > projects – Office, the Windows kernel, or IE. I can guess it’s C++, or > I could Google for it, I suppose, and given the age of the products I > can rule out Java. But there’s nothing in any of these complex products > that is customer-visible that rules out implementation in any > sufficiently-capable language. Thx for sharing and Happy New Year. Robert – > M. Edward (Ed) Borasky, FBG, AB, PTA, PGS, MS, MNLP, NST, ACMC(P) > [http://borasky-research.blogspot.com/](http://borasky-research.blogspot.com/) > > If God had meant for carrots to be eaten cooked, He would have given > rabbits fire. – “The real romance is out ahead and yet to come. The computer revolution hasn’t started yet. Don’t be misled by the enormous flow of money into bad defacto standards for unsophisticated buyers using poor adaptations of incomplete ideas.” - Alan Kay ---
**Author:** ![npenkov](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ee59a6/32.png) [@npenkov](https://www.ruby-forum.com/u/npenkov)\ **Post date:** [December 31, 2006, 10:30am UTC](https://www.ruby-forum.com/t/strong-encapsulation-static-typing-and-unit-testing/80689/7 "2006-12-31T10:30:07Z")
On 12/30/06, M. Edward (Ed) Borasky [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > Nice reading but I guess we are getting off topic > say, a social web site, an algorithmic composition package or a queuing > theory model. What I meant is the following, Is it possible to hide the choice of the implementation language from the customer, can an abstraction be made to “get the job done”. But this still might be OT, do not mind too much about it. Thx for your thaughts Ed and Happy New Year to all 🙂 Cheers Robert – > – “The real romance is out ahead and yet to come. The computer revolution hasn’t started yet. Don’t be misled by the enormous flow of money into bad defacto standards for unsophisticated buyers using poor adaptations of incomplete ideas.” - Alan Kay