validates_presence_of :purpose

Do you know what's behind these buzzwords: CouchDB / Couchapp / Sammy.js? Not really? Then please look at this article now: Sammy.js, CouchDB, and the new web architecture. The title says it all.

This setup happens to be the field of my diploma thesis, friendly sponsored and supported by Upstream. During the next months I'll develop a super duper thing with these technologies, and then I'll write 80 scientific pages about it. Yees, I'm not that much looking forward to the second part! Until then, I'm planning to semi-regularly blog about my findings.

I'm not allowed to share the code before I have the diploma in my hands. But, because my workmate Frank Proessdorf is so jealous of what I do, he and I started working on an app with a similar setup on our Upstream Research Fridays, to try things out. Here it is. Don't expect anything yet.

Today I'm going to tell you about some details of my testing setup. My *cough* supervising tutor Alexander Lang already wrote down all there is to know yet about Test-Driven Development with Cucumber-Culerity-Celerity and Couchapps.

But there are a few things that will make your life hard, when the almost perfect Rails testing world has spoiled you as much as me. One thing is that we have to deal with a lot of asynchrony. Sammy renders the page, loads the data from the couch, and whenever the data is there it gets rendered into the page. The best way to do this is via callbacks. I'm going to write another blog post about that soon.

In the integration test the problem is that celerity doesn't behave as it claims it does:

$browser.wait

is supposed to make the test wait until everything is rendered completely. But for whatever reason it doesn't. The result is that your test fails because it searches for your expressions in an unfinished page.

Because of that, in culerity we need something like:

sleep 0.4

after every follow, press and go-to-path step. When using culerity in a Rails environment, this usually is enough. Sammy behaves a bit more unpredictable - it sometimes takes more than a whole second until everything is loaded.

Solution? We can either increase the sleep time a lot, but that's not very nice, the features need long enough to run as it is. Fortunately we can use another method that's build into celerity: wait_while.

I created a div "spinner" somewhere in index.html:

 <div id="spinner"></div>

You can also add an actual spinner gif here. Just take care to place the div outside of your sammy element selector ("#main" by default), because this div gets replaced all the time.

We need to show that div before every route that gets run. In application.js:

before(function() {
  $('#spinner').show();
});

And we need to hide it after your rendering is completed. I haven't found an ideal solution where to do that, it depends on the application you are writing. As a quick and dirty fix, you can add it as a last line in sammy's partial function, in sammy.js:

partial: function(path, data, callback) {
  //...
  $('#spinner').hide();
},

I prefer to have more control about when I hide it, as my partial calls sometimes have nested callbacks. So I put it in application.js, resp. in my controllers, after each render call or in the partial callbacks. I admit this still sucks a bit.

Finally, amend the cucumber step:

When /I wait for the AJAX call to finish/ do
  sleep 0.2
  puts 'Waiting for page to load ...' if $browser.div(:id, 'spinner').visible?
  $browser.wait_while { $browser.div(:id, 'spinner').visible?} 
end

The browser still needs to sleep a bit before it actually finds the spinner div. But with this step in my common_culerity_steps.rb, the features finally run smoothly.