Baby Step #1 with Rails, RSpec and Cucumber

There are lots of resources on the web to help get started with RSpec and Cucumber but there's still a learning curve that I think only experience will overcome. So I decided just to dive in. I don't claim what I've done here is right, or even a good idea, but it's where I started.

My initial goal is just to walk through the 'outside in' red/green/refactor process of writing a feature then examples without spending to much time worrying if I selected the right story or if it's implemented it correctly.

This initial cycle is mostly about learning what the tools can do for me.

The simplest story that I can imagine goes like this:

as a reader I want to browse the site so that I can read it's content.

So with that story in hand It's time to write my first feature

 #  ./features/reader_browses.feature
Feature: browsing
 As a reader
 I want to browse the site
 So that I can view it's content

Scenario: visit the homepage
 When I go to the homepage
 Then I should see "Hello world!"

Next I run Cucumber, 'rake features', and get the following....

 Feature: browsing
 As a reader
 I want to browse the site
 So that I can view it's content

Scenario: visit the homepage       # features/reader_browses.feature:6
 When I go to the homepage        # features/step_definitions/webrat_steps.rb:10
   undefined method `root_path' for # (NoMethodError)
   /home/mgreenly/Projects/blog/features/support/paths.rb:6:in `/^I go to (.+)$/'
   features/reader_browses.feature:7:in `When I go to the homepage'
 Then I should see "Hello world!" # features/step_definitions/webrat_steps.rb:93

1 scenario
1 failed step
1 skipped step
rake aborted!

So the first error I get is because we don't have a default route, so lets fix it by adding the following line in "./config/routes.rb"

map.root :controller => 'posts'

Then I run Cucumber again, "rake features", and get the following....

 Feature: browsing
As a reader
I want to browse the site
So that I can read it's content

Scenario: visit the homepage       # features/reader_browse.feature:6
 When I go to the homepage        # features/step_definitions/webrat_steps.rb:10
   uninitialized constant PostsController (NameError)
   (eval):2:in `/^I go to (.+)$/'
   features/reader_browse.feature:7:in `When I go to the homepage'
 Then I should see "Hello world!" # features/step_definitions/webrat_steps.rb:93

1 scenario
1 failed step
1 skipped step
rake aborted!

So now it's telling me that the default route points to a PostsController and that controller doesn't exist. So lets create both the controller and it's rspec framework with the built in generator.

./script/generate rspec_controller posts

Now I'll run the spec, "rake spec", to see what I get

 ..

Finished in 0.045209 seconds

2 examples, 0 failures

It passes of course because the controller doesn't do anything and the spec doesn't make any requirements on it.

So lets see what Cucumber says now, "rake features"

 Feature: browsing
 As a reader
 I want to browse the site
 So that I can view it's content

Scenario: visit the homepage       # features/reader_browses.feature:6
 When I go to the homepage        # features/step_definitions/webrat_steps.rb:10
   No action responded to index. Actions:  (ActionController::UnknownAction)
   /usr/local/stow/ruby-1.8.7-p72/lib/ruby/1.8/benchmark.rb:308:in `realtime'
   (eval):2:in `/^I go to (.+)$/'
   features/reader_browses.feature:7:in `When I go to the homepage'
 Then I should see "Hello world!" # features/step_definitions/webrat_steps.rb:93

1 scenario
1 failed step
1 skipped step
rake aborted!

There's still an error but it's changed. Now it's complaining because the there's no 'index' action on the Posts controller. So lets drop back to the rspec example for the Posts controller and create a requirement for the index action. Remember first I want it to fail, then pass.

# in ./spec/controllers/posts_controller_spec.rb
describe "GET 'index'" do
it "should be successful" do
get 'index'
  response.should be_success
end
end

So now when I run "rake spec" I get....

.F.

1)
ActionController::UnknownAction in 'PostsController GET 'index' should be successful'
No action responded to index. Actions:
./spec/controllers/posts_controller_spec.rb:12:

Finished in 0.052123 seconds

3 examples, 1 failure
rake aborted!

Now that the spec is failing we can try to satisfy it. To do that I just create an empty file at "app/views/posts/index.erb" and then rerun "rake spec"

 ...

Finished in 0.049891 seconds

3 examples, 0 failures

So now that the spec passes I run Cucumber again, "rake features", and get ....

 Feature: browsing
 As a reader
 I want to browse the site
 So that I can view it's content

Scenario: visit the homepage       # features/reader_browses.feature:6
 When I go to the homepage        # features/step_definitions/webrat_steps.rb:10
 Then I should see "Hello world!" # features/step_definitions/webrat_steps.rb:93
   Could not parse document (RuntimeError)
   features/reader_browses.feature:8:in `Then I should see "Hello world!"'

1 scenario
1 failed step
1 passed step
rake aborted!

It's still failing but now it's upset because it can't find the "Hello world!" text on the index page. This is easy to fix, I just need to add the text to "app/views/posts/index.erb". Now I run "rake features".....

Feature: browsing
 As a reader
 I want to browse the site
 So that I can view it's content

Scenario: visit the homepage       # features/reader_browses.feature:6
 When I go to the homepage        # features/step_definitions/webrat_steps.rb:10
 Then I should see "Hello world!" # features/step_definitions/webrat_steps.rb:93

1 scenario
2 passed steps

It passes. Just to make sure I didn't screw anything up I run "rake spec" on more time.

...
Finished in 0.049713 seconds
3 examples, 0 failures

That makes one successfull pass through an outside-in red/green/refactor cycle using Cucumber and Rspec with Rails.