May 2011 - Esug-list - lists.esug.org

Fwd: Re: Proposal for Mock Objects at ESUG 2011
by Joseph Pelrine June 3, 2011

June 3, 2011

Hi all, I took the liberty of forwarding this mail to Tim Mackinnon and Steve Freeman, who invented the original Mock Objects. Here's Steve's answer. I'll forward further mails to this list. -------- Original Message -------- Subject: Re: [Esug-list] Proposal for Mock Objects at ESUG 2011 Date: Fri, 27 May 2011 09:25:30 +0100 From: Steve Freeman <steve(a)m3p.co.uk> To: Joseph Pelrine <jpelrine(a)metaprog.com> You should talk to Tim, he wrote a mocks library in about 3 classes (which is what it should take). He also has some interesting experience from the Kapital project that doesn't have unit tests. I hadn't realised that the ST world was behind in this respect. S. On 27 May 2011, at 05:41, Joseph Pelrine wrote: > FYI > > -------- Original Message -------- > Subject: [Esug-list] Proposal for Mock Objects at ESUG 2011 > Date: Fri, 27 May 2011 08:36:27 +0400 > From: Dennis Schetinin <chaetal(a)gmail.com> > To: ESUG Mailing list <esug-list(a)lists.esug.org> > > > > Hello! > > I'd like to explore interest to Mock Object in Smalltalk society. I'm > currently working on the topic, preparing a paper and presentation > targeting at ESUG 2011. > > I plan to present Mock Objects technique itself and a framework named > Mocketry as a tool helping to apply it in practice. Of course I'll > provide a small example to illustrate some of the ideas. > > Apparently, Mocks technique is not popular tool among Smalltalkers. It > even seems (to me), TDD is not as widely used as it could and should be > (despite the fact it was born in Smalltalk). I have been using TDD and > Mocks for many years in different projects with Smalltalk and other > languages. Sometimes it was hard, sometimes I was even giving it up, but > by now I think I have sufficient experience to state that TDD in general > and Mock Objects specifically do deserve (at least) more attention by > smalltalkers. Yes, Smalltalk is great language and it has great tools. > This damps some aspects of the problems TDD and Mocks address, but for > sure does not remove them totally. More than that, I can say I was most > productive in Smalltalk when I used "classic TDD" and mocks in conjunction. > > > So, are other Smalltalkers interested in this topic? Do you think it > worth to be presented at the conference? What are the problems you'd > like to discuss there? > > TIA > > -- > Dennis Schetinin > <Attached Message Part.txt> Steve Freeman Winner of the Agile Alliance Gordon Pask award 2006 Book: http://www.growing-object-oriented-software.com +44 (0) 797 179 4105 M3P Limited. http://www.m3p.co.uk Registered office. 2 Church Street, Burnham, Bucks, SL1 7HZ. Company registered in England & Wales. Number 03689627

9 12

Re: [Esug-list] ESUG SummerTalk - Fuel, binary object serializer
by Marcus Denker June 1, 2011

June 1, 2011

On May 25, 2011, at 7:35 PM, Yoshiki Ohshima wrote: > At Wed, 25 May 2011 15:28:00 +0200, > Mariano Martinez Peck wrote: >> >> One of the most important uses we want to do with Fuel (in a future) is to be able to use it for Monticello (to replace mzc). >> The idea in addition is to be able to boostrap a really small pharo image (hetzel) and be able to load stuff without needing a compiler. > > Sounds interesting! Can I learn about "hetzel" somewhere? > We are working on how to build minimal Pharo kernels (with the goal of a declarative bootstrap so you can build your own version of Smalltalk running in the normal Pharo image to experiment with new language features, as one example, or create a minimal image for deployment). There is some information from Nicolas Paez who worked on this when visiting RMOD last year: http://www.fast.org.ar/smalltalks2010/videos/Seed+project%3A+The+challenge+… http://rmod.lille.inria.fr/archives/talks/2010-Smalltalks-Paez-Seed.pdf The status is that we learned a lot and continue to work on it... more to come later ;-) Marcus -- Marcus Denker -- http://www.marcusdenker.de INRIA Lille -- Nord Europe. Team RMoD.

7 22

Re: [Esug-list] Proposal for Mock Objects at ESUG 2011
by Colin Putney June 1, 2011

June 1, 2011

On Fri, May 27, 2011 at 12:42 PM, Frank Shearar <frank.shearar(a)gmail.com> wrote: > You miss the point of mocks. Mocks are there to allow you to test your > code quickly and cheaply against things that may not work in a quick > manner. Not likely. Hernán has been around the block and he speaks from long experience and deep thinking on software design. If you read his post a little more carefully, you'll see that he distinguishes between test doubles in general and mocks as a particular form of test double. He uses test doubles - you don't get 23,000 tests to run in 7 minutes without them. It's just *mocks* that are mostly unnecessary. Personally, I find that mocks are *very* useful in a few very specific situations, but they can cause problems it other situations. They're like a very specialized tool - invaluable when you need it, but kept in the bottom of the toolbox and not used very often. Where I find them useful is in testing communication. For example, I'll use a MockWritestream to throw an exception if the code under test writes something unexpected into the stream. It's handy when testing code that writes out files in a particular format, or communicates with remote systems over the network. It might also be useful to test communications across formal module boundaries, where it's particularly important that a specific protocol be used - eg, for something like Prevalayer. My favourite testing pattern is TrivialImplementation. Instead of using a test double or an expensive "real" object, I often create a cheap/trivial implementation of the objects that collaborate with the objects I'm testing. For example, Monticello2 has several repository classes. There are implementations that store code in a single file, in a directory of files, on a remote machine via sockets, on a web server via HTTP etc. There's also a trivial implementation that just uses an in-memory Dictionary for storage. It's a complete implementation of the repository protocol, and Monticello can use it "for real", but it's not as robust as the other kinds of repository. All the repository implementations, including MemoryRepository, have a suite of tests that ensure that they work correctly. But when I'm testing other parts of Monticello that interact with a repository, those tests use a MemoryRepository. I know that BDD folks like to talk about testing behaviour rather than state, but I don't find the distinction useful. Testing state breaks the encapsulation of the objects under test, and couples the test too closely to their internal implementation. Testing behaviour using mocks *does the same thing*; it just restricts the implementation in a different way. I find it's better to give the implementation a degree of freedom by testing "results". Figuring out what result you're looking for can be difficult - it requires thinking about what a passing test really tells you. Here's an example - let's say we we're testing an implementation of Set. Here's the version that tests state: | set | set := Set new. set add: 3. self assert: (set instVarNamed: 'array') = #(nil nil nil 3 nil) Here we test behaviour: | set | mock := MockArray new: 5 mock expect: (Message selector: #at:put: arguments: #(4 3)). set := Set withArray: mock. set add: 3. I prefer this approach. It gives the implementation a lot of freedom, while ensuring that it does what we really want: | set | set := Set new. set add: 3. self assert: (set includes: 3). In short, I agree with Hernán. Mocks can be useful, but they're often overused. In most cases, they're unnecessary. Colin

4 5

Looking for a PhD position
by Stéphane Ducasse May 31, 2011

May 31, 2011

Hi guys Here is a student that is looking for a PhD grant.... I do not meet him but just forward to you his profile. Stef Dear smalltalkers, I am a student in computer sciences at the Henri Poincaré University of Nancy (France) and I am currently studying for a master's degree called "Software : theory, methods and engineering". I am looking for a Ph.D position in programming language design, component-based programming or more generally in software engineering. Please find enclosed my CV. I am at your disposal to provide any other relevant information. Cordially, Camille Teruel

1 0

Re: [Esug-list] Recherche de thèse
by Stéphane Ducasse May 31, 2011

May 31, 2011

au lieu que cela soit moi qui envoie un mail peut etre que cela serait mieux que tu le fasses. il y a esug-list ESUG Mailing list <esug-list(a)lists.esug.org> si tu ne peux pas publier alors ecrit un petit mail et je ferais un forward. sinon tu peux contacter oscar nierstrasz (universite de berne), michele lanza (universite de lugano - plus sur la visualization), theo d'hont (belgique), noury bouraqadi, Stef On May 31, 2011, at 9:52 AM, camille teruel wrote: > Bonjour M.Ducasse, > > En effet j'ai oublié de remettre la partie stage, voici le CV corrigé. > L'article, en tant que "position paper", n'a pas été publié dans les actes de la conférence, mais je l'ai quand même mentionné étant donné que c'est ma seule publication à l'heure actuelle... > > Cordialement, > Camille Teruel > > PS: J'ai regardé un peu plus en profondeur Smalltalk hier soir, du coup, je retire ce que j'ai dit, c'est un langage objet dynamique presque comme les autres. Beaucoup de monde parle de Ruby comme d'un mini-Smalltalk et de l'objet dynamique reste de l'objet dynamique alors dans ma tête c'était Ruby=Smalltalk=Groovy=..., mais au final c'est assez différent. > <cv_teruel.pdf>

1 0

Don't forget: Your talks at ESUG
by stephane ducasse May 30, 2011

May 30, 2011

19th International Smalltalk Joint Conference - Call for Contributions Edinburgh, England August 20-26 2011; Camp Smalltalk September 20-21 http://esug.org/Conferences/2011/ This call includes: Developer program Free ESUG tickets International Workshop http://esug.org/Conferences/2011/International-Workshop-on-Smalltalk-Techno… Student Volunteer http://esug.org/Conferences/2011/Student+Volunteers+program Camp Smalltalk: Saturday 20th - Sunday 21st August 2011. ESUG conference: Monday 22nd - Friday 26th August 2011. This year will be held the - 7th edition of the Innovation Technology Awards where prizes will be awarded to authors of best pieces of Smalltalk-related projects - an international workshop on Smalltalk and dynamic languages http://www.esug.org/wiki/pier/Conferences/2011/International-Workshop-on-Sm… - ESUG will offer 10 free entrance tickets. To get a free ticket you should send a mail to the esug board (board(a)esug.org) Subject: [ESUG 2011 Free entrance] + your name And you should write a small motivation. You can support the ESUG conference in many different ways: * Sponsor the conference. New sponsoring packages are described at http://www.esug.org/supportesug/becomeasponsor/ * Submit a talk, a software or a paper to one of the events. See below. * Attend the conference. We'd like to beat the previous record of attendance (156 participants at Brest and 170 people at Amsterdam, 150 at Barcelona)! * Students can get free registration and hosting if they enroll into the the Student Volunteers program. See below. Developers Forum: International Smalltalk Developers Conference ------------------------------------------------------------------------ This year we are looking for YOUR experience on using Smalltalk. In addition, we are looking for tutorials. The list of topics includes, but is not limited to the following: * XP practices * Development tools * Experience reports * Model driven development * Web development * Team management * Meta-Modeling * Security * New libraries & frameworks * Educational material * Embedded systems and robotics * SOA and Web services * Interaction with other programming languages Submissions due on 1 July 2010 Notification of acceptance on 5 of July 2010 More information at http://www.esug.org/conferences/2011 How to submit? ------------------ Pay attention: the places are limited so do not wait till the last minute to apply. Prospective presenters should submit a request to board(a)esug.org AND stephane.ducasse(a)free.fr following the template below. Please use this template since the emails will be automatically processed! Subject: [ESUG 2011 Developers] + your name First Name: Last Name: Email where you can always be reached: Title: Abstract: Bio: Any presentation not respecting this form will be discarded automatically Innovation Technology Award ------------------------------------------------------------------------ We are proud to announce the 6th Innovation Technology Awards. The top 3 teams with the most innovative software will receive, respectively, 500 Euros, 300 Euros and 200 Euros during an awards ceremony at the conference. Developers of any Smalltalk-based software are welcome to compete. This year we will request 3-5min videos. More information at http://www.esug.org/Conferences/2011/Innovation+Technology+Awards Student Volunteer Program ------------------------------------------------------------------------ If you are a student wanting to attend ESUG, have you considered being a student volunteer? Student volunteers help keep the conference running smoothly; in return, they have free accommodations, while still having most of the time to enjoy the conference. More information at http://www.esug.org/conferences/2011 http://www.esug.org/Conferences/2011/Student+Volunteers+program We hope to see you there and have fun together. Ze ESUG board_______________________________________________

2 1

Proposal for Mock Objects at ESUG 2011
by Dennis Schetinin May 28, 2011

May 28, 2011

Hello! I'd like to explore interest to Mock Object in Smalltalk society. I'm currently working on the topic, preparing a paper and presentation targeting at ESUG 2011. I plan to present Mock Objects technique itself and a framework named Mocketry as a tool helping to apply it in practice. Of course I'll provide a small example to illustrate some of the ideas. Apparently, Mocks technique is not popular tool among Smalltalkers. It even seems (to me), TDD is not as widely used as it could and should be (despite the fact it was born in Smalltalk). I have been using TDD and Mocks for many years in different projects with Smalltalk and other languages. Sometimes it was hard, sometimes I was even giving it up, but by now I think I have sufficient experience to state that TDD in general and Mock Objects specifically do deserve (at least) more attention by smalltalkers. Yes, Smalltalk is great language and it has great tools. This damps some aspects of the problems TDD and Mocks address, but for sure does not remove them totally. More than that, I can say I was most productive in Smalltalk when I used "classic TDD" and mocks in conjunction. So, are other Smalltalkers interested in this topic? Do you think it worth to be presented at the conference? What are the problems you'd like to discuss there? TIA -- Dennis Schetinin

6 5

Re: [Esug-list] Proposal for Mock Objects at ESUG 2011
by simondenier May 28, 2011

May 28, 2011

That's interesting. I recently started to use Cucumber with Rails, which looks like another step in BDD with specs written in look-alike natural language. Hard to beat in terms of readibility, even with the Smalltalk syntax. But that's another topic. http://cukes.info/ On topic I started to read the GOOS book written by two pioneers of mocks, and I think it's a recommended reading on the topic of objects + TDD + mock. Just read the first chapters for now but it's in line with my own conception of objects yet offers some interesting insights about design. I think Tim McKinnon which has been a regular participant of Smalltalk events in the past years might have a word or two on the topic :) http://www.growing-object-oriented-software.com/ -- View this message in context: http://forum.world.st/Proposal-for-Mock-Objects-at-ESUG-2011-tp3554367p3554… Sent from the ESUG mailing list archive at Nabble.com.

2 1

Re: [Esug-list] Fwd: Re: Proposal for Mock Objects at ESUG 2011
by Frank Shearar May 28, 2011

May 28, 2011

On 27 May 2011 21:56, Colin Putney <colin(a)wiresong.com> wrote: > On Fri, May 27, 2011 at 12:42 PM, Frank Shearar <frank.shearar(a)gmail.com> wrote: >> You miss the point of mocks. Mocks are there to allow you to test your >> code quickly and cheaply against things that may not work in a quick >> manner. > > Not likely. Hernán has been around the block and he speaks from long > experience and deep thinking on software design. If you read his post > a little more carefully, you'll see that he distinguishes between test > doubles in general and mocks as a particular form of test double. He > uses test doubles - you don't get 23,000 tests to run in 7 minutes > without them. It's just *mocks* that are mostly unnecessary. Hernan, I didn't mean to bite your head off. Next time I'll pause a bit longer. > Personally, I find that mocks are *very* useful in a few very specific > situations, but they can cause problems it other situations. They're > like a very specialized tool - invaluable when you need it, but kept > in the bottom of the toolbox and not used very often. Where I find > them useful is in testing communication. For example, I'll use a > MockWritestream to throw an exception if the code under test writes > something unexpected into the stream. It's handy when testing code > that writes out files in a particular format, or communicates with > remote systems over the network. It might also be useful to test > communications across formal module boundaries, where it's > particularly important that a specific protocol be used - eg, for > something like Prevalayer. Indeed, and in these cases and the other appropriate use cases I'd like to see a nicely written, widely used, standardised framework precisely so we (I) don't have to write our (my) own. Anyhow, talk's cheap, and once I've finished my current chunk of work I'll try beat SSpec into shape. frank > My favourite testing pattern is TrivialImplementation. Instead of > using a test double or an expensive "real" object, I often create a > cheap/trivial implementation of the objects that collaborate with the > objects I'm testing. For example, Monticello2 has several repository > classes. There are implementations that store code in a single file, > in a directory of files, on a remote machine via sockets, on a web > server via HTTP etc. There's also a trivial implementation that just > uses an in-memory Dictionary for storage. It's a complete > implementation of the repository protocol, and Monticello can use it > "for real", but it's not as robust as the other kinds of repository. > All the repository implementations, including MemoryRepository, have a > suite of tests that ensure that they work correctly. But when I'm > testing other parts of Monticello that interact with a repository, > those tests use a MemoryRepository. > > I know that BDD folks like to talk about testing behaviour rather than > state, but I don't find the distinction useful. Testing state breaks > the encapsulation of the objects under test, and couples the test too > closely to their internal implementation. Testing behaviour using > mocks *does the same thing*; it just restricts the implementation in a > different way. I find it's better to give the implementation a degree > of freedom by testing "results". Figuring out what result you're > looking for can be difficult - it requires thinking about what a > passing test really tells you. > > Here's an example - let's say we we're testing an implementation of > Set. Here's the version that tests state: > > | set | > set := Set new. > set add: 3. > self assert: (set instVarNamed: 'array') = #(nil nil nil 3 nil) > > Here we test behaviour: > > | set | > mock := MockArray new: 5 > mock expect: (Message selector: #at:put: arguments: #(4 3)). > set := Set withArray: mock. > set add: 3. > > I prefer this approach. It gives the implementation a lot of freedom, > while ensuring that it does what we really want: > > | set | > set := Set new. > set add: 3. > self assert: (set includes: 3). > > In short, I agree with Hernán. Mocks can be useful, but they're often > overused. In most cases, they're unnecessary. > > Colin >

4 4

Re: [Esug-list] ESUG SummerTalk - Fuel, binary object serializer
by Marcus Denker May 26, 2011

May 26, 2011

On May 26, 2011, at 9:41 PM, Mariano Martinez Peck wrote: > > > On Thu, May 26, 2011 at 9:29 PM, Yoshiki Ohshima <yoshiki(a)vpri.org> wrote: > BTW, the page (http://rmod.lille.inria.fr/web/pier/software/Fuel) > says: > ... > Gofer new > squeaksource: 'Fuel'; > package: 'ConfigurationOfFuel'; > load. > ((Smalltalk at: #ConfigurationOfFuel) project latestVersion) load: #(Core Tests Benchmarks). > > And there is always an up-to-date build on Hudson: https://pharo-ic.lille.inria.fr/hudson/job/Fuel/ This is automatically rebuild when Pharo 1.3 gets updates (which means 1-2 times per day). (And on commits to the Fuel repository, but this trigger seems to not work right now...) Marcus -- Marcus Denker -- http://www.marcusdenker.de INRIA Lille -- Nord Europe. Team RMoD.

1 0