On Sun, Apr 27, 2008 at 10:05 AM, Dan North <[EMAIL PROTECTED]> wrote: > Hi Matthew. > > I don't think it's off-topic at all. I would estimate around 80% of the > traffic on this list is about "how do I test such-and-such with rails?". > > Rails is designed for a particular subset of web applications, namely ones > that look a lot like basecamp. They mostly involve capturing, updating or > presenting data, in a very two-tier, database-on-the-screen kind of way. The > giveaway is having ActiveRecord as the persistence layer. The other clue is > in the fact that you have to define a database before you can fire it up and > get the "you're on rails" welcome page. All the examples and tutorials I've > seen (outside of the rspec world) start by defining database tables and > their corresponding ActiveRecord classes, and then building up the > application from there. > > I describe these applications as being mostly surface area (i.e. front end > and back end), with very little volume (i.e. interesting behaviour other > than CRUD and presentation). Now don't get me wrong, you can do a lot with > these kinds of applications, and they are incredibly useful. In fact most > "enterprise" applications are simply variations on this theme. But the rails > stack simply isn't geared up for outside-in development, or, I would venture > to say, for many of the applications it is being targeted at. > > I presented rspec and rails in a session with David Chelimsky and Aslak at > last year's RailsConf Europe and I was amazed at how brilliantly David and > Aslak had beaten rails into submission in order to present an outside-in, > view-first approach to developing an application. I would never have thought > of the approach they came up with - I would have given up in despair long > before that! > > The tight coupling between the domain object classes and the persistence > mechanism means you either have to mock domain objects - which simply > doesn't make any sense for anaemic data-only objects - or couple every > example to your database, and life's too short to have a 30 minute build for > a web app. > > So now you have one of two options. Firsly, you can accept that rails is > designed for large surface area applications, and be prepared to compromise > on testability and the ability to do outside-in development. The other is to > use a different ruby web stack such as ramaze (http://ramaze.net) which > allows you to start at the outside and work inwards, evolving separate > views, controllers and models as you need to (and only when you need to). > Side note: I just noticed that when you run ramaze --create blah, you get a > spec directory with some simple "GET / should return 200" specs. And not a > database in sight. Sweet! > > Cheers, > Dan > > ps. I'll be turning this into a longer and more detailed rant on my blog > soon :)
Please do. I'd especially like to know more about outside-in style you mentioned. Rails is my first experience with web development and I don't have a good intuitive notion of what that different approach would be. Send me (us?) the link when it's done :) Cheers, Helder > > > 2008/4/24 Matthew Lins <[EMAIL PROTECTED]>: > > > > > > > This is a little off topic, but I use rSpec and I'm starting to question > the quality of my specs. In my research and attempt to learn how to write > better specs, I've came across a few things that I'd like to discuss. > > > > I'm having more and more difficulty understanding BDD. The more I read > and the more I watch, the more questions I come up with. Let me just ask a > couple of general questions to start this off. > > > > Is 'shoulda' actually following the principals of BDD? But, I guess > that's not really a good question. Is 'shoulda' encouraging it's users to > follow the principals of BDD? I see all of the macros like: > > > > should_belong_to > > > > should_require_attributes > > > > To me, that is not BDD. Basically that's just testing whether or not your > model contains a certain code fragment. But, that brings me to my next > question. > > > > Is BDD even possible with Rails? (I think it is, but I ask myself that > more and more lately) > > > > I just picked a random model in the application I'm currently working on. > The 'Picture' model. I use the attachment_fu plugin, which helps this model > handle pictures (it creates thumbnails, validates sizes, etc.) I wiped out > all the code I had and all the specs I had. I started from scratch: > > > > > > ---------------------------------- > > > > class Picture < ActiveRecord::Base > > > > end > > > > ---------------------------------- > > > > The first piece of code I would write if I wasn't using BDD, would be: > > > > > > ---------------------------------- > > > > class Picture < ActiveRecord::Base > > > > validates_as_attachment > > > > end > > > > ---------------------------------- > > > > Which basically handles all of my validation. So, from a BDD perspective, > how do I spec that? I know, I know, I should be writing the specs first. > But, what do I do about these helpers that come with plugins. Do I write a > spec: > > > > ---------------------------------- > > > > describe Picture, 'with a blank filename' do > > > > before(:each) do > > @picture = Picture.new valid_picture_attributes.except(:filename) # > This uses some rSpec helpers > > end > > > > it do > > @picture.should_not be_valid > > end > > > > end > > > > ----------------------------------- > > > > So, the most simple way to solve that would be (this is part of what > 'validates_as_attachment' does): > > > > ---------------------------------- > > > > class Picture < ActiveRecord::Base > > > > validates_presence_of :filename > > > > end > > > > ---------------------------------- > > > > But, now what, I'm going to reverse engineer this plugin's helper? I'll > just spec it all out and eventually refactor and put the > 'validates_as_attachment' back? Or, maybe since this is a plugins helper I > don't even need to test any of this. It's the author of the plugin's > responsibility. This is were my brain enters an infinite loop (one example > anyway, hehe). I just can't seem to nail down the workflow when specing > rails apps. I also have a hard time determining what to spec. > > > > I know I asked a lot of questions, but basically I'm just trying to find > out if people are actually following the BDD principals strictly when > writing Rails apps. If you are can you give me some insight in the above > example? > > > > Thanks, > > > > Matt Lins > > > > _______________________________________________ > > > > rspec-users mailing list > > rspec-users@rubyforge.org > > http://rubyforge.org/mailman/listinfo/rspec-users > > > > > _______________________________________________ > rspec-users mailing list > rspec-users@rubyforge.org > http://rubyforge.org/mailman/listinfo/rspec-users > -- "If I have not seen as far as others, it is because giants were standing on my shoulders" -- Jeff Goll _______________________________________________ rspec-users mailing list rspec-users@rubyforge.org http://rubyforge.org/mailman/listinfo/rspec-users
