Sprinkle Some Integration Tests into a Mock Heavy Test Suite

I like mocks and stubs and I use them liberally in my tests. This practice, however, is not without danger: If my models, views, and controllers are all tested in isolation then how will I know if a model change busts a controller or a view? Here's something I like to drop in at the end of every controller spec:




1
2
3
4
5
6
7
8
9
10
11
12
 
describe JerkStoreController, "with views integrated and real objects" do
  integrate_views
  
  it "should render the page without blowing up" do
    store = JerkStore.create!(:name => "Costanza's house of bargins")
    store.products << Jerk.create!(:name => "Puddy") <<
                      Jerk.create!(:name => "Newman") <<
                      Jerk.create!(:name => "Steinbrenner")

    post :show, :id => store.id
  end
end
Not a mock or a stub as far as the eye can see and I'm even integrating views. Normally RSpec doesn't render the view in a controller spec, but if you include "integrate_views" it will. So now if I make some changes that bust MVC integration my spec will let me know. I don't try to exercise all the possible paths with these tests -- rather they are a safety net for problems isolated specs won't detect.

Comments

Michael said…
This can get very complex once your create/view logic is not so simple anymore(not to mention validations...). Therefor i try to stay with the
it "renders" do;assigns[:post]=posts(:one); render 'show';end

approach
December 3, 2008 at 2:06 AM
Anonymous said…
i think that's a good start but ultimately you might want to start writing full blown integration/acceptance tests.

have you considered cucumber/webrat - by rendering your views and clicking on actual links and filling out forms instead of just posting to your actions this spans a much wider range of problems than a simple "render this view in this action" call
December 4, 2008 at 5:14 AM
Post a Comment

Popular posts from this blog

What's a Good Flog Score?

I've been using Flog to measure the complexity of my Ruby code and I was wondering how others interpret Flog numbers. I'll go first with my opinions: Score of Means 0-10 Awesome 11-20 Good enough 21-40 Might need refactoring 41-60 Possible to justify 61-100 Danger 100-200 Whoop, whoop, whoop 200 + Someone please think of the children (note: these are scores for an individual method) The 20 - 60 range is interesting to me. Sometimes the complexity of what you're doing will justify the score and other times the method is in desperate need of refactoring. The highest Flog score I've seen in the wild was in the 300's. What's you're personal high and what do you think of my rankings? In other news, I've redesigned the look of my blog so if you only see my post through a reader you might want to stop on by, take a look, and tell me what you think.
Read more

SICP Wasn’t Written for You

The number of software luminaries who sing the praises of “ Structure and Interpretation of Computer Programs ” (referred to as SICP) is such a long list that you might think only a crazy person would take issue with it. However, to ignore SICP’s problems and continue to blindly recommend it seems just as crazy. SICP was the textbook for MIT’s introductory programming class and was a bit of a departure from other into to computer science textbooks at the time.  Wikipedia sums it up nicely:  “Before SICP, the introductory courses were almost always filled with learning the details of some programming language, while SICP focuses on finding general patterns from specific problems and building software tools that embody each pattern.”  Which sounds awesome, but does essentially say that abstract principles will be introduced before the nuts and bolts of a language.  If you think about that for a minute, you may see where the problems will be. When I was training to be a...
Read more

Point Inside a Polygon in Ruby

Recently my team needed to find out if a point was inside a given polygon and, as usual, we found some code on the internet that did what we wanted. And, as usual, there wasn't much explanation as to what it was doing. Here's the code (after we converted it to Ruby): 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 def contains_point? (point) c = false i = -1 j = self .size - 1 while (i += 1 ) < self .size if (( self [i].y <= point.y && point.y < self [j].y) || ( self [j].y <= point.y && point.y < self [i].y)) if (point.x < ( self [j].x - self [i].x) * (point.y - self [i].y) / ( self [j].y - self [i].y) + self [i].x) c = !c end end j = i end return c end end So, you know, it works and I'm grateful to somebody for posting it but we had no idea how it works. So we wrapped 2 tests around it (one where the point is not in the polygon and another where it is...
Read more