Category: Rails

The test_spec_on_rails plugin, which provides some nice helpers for testing Rails applications when using test/spec, has moved from Subversion to Git.

Check out the profile page or clone the repository itself from this path:

git://github.com/pelargir/test_spec_on_rails.git

I’ve added a new assertion to test_spec_on_rails that enables verification that validates_presence_of is being called correctly on your ActiveRecord models. For example, say you have a model like this:

class User < ActiveRecord::Base
  validates_presence_of :first_name, :last_name
end

You would typically test this validation by leaving a field blank, calling valid? or save on the instance, and checking the errors collection for messages:

describe "User" do
  it "should validate presence of first name" do
    user = User.new(:first_name => nil)
    user.valid?
    user.errors.on(:first_name).should == "can't be blank"
  end
end

Aside from being tedious to write, this method of testing isn't very fast. With the latest version of test_spec_on_rails your test becomes:

describe "User" do
  it_should_validate_presence_of :first_name, :last_name
end

Nice, simple... and fast. Behind the scenes, validation reflection is being used to ensure that validates_presence_of is being called on the model class. The model itself is never instantiated which speeds things up. The test itself is also very clean and easy to read. (You can't get much cleaner than a single line of code, right?)

What about verifying options that are passed to the validation? This new enhancement handles that too:

class User < ActiveRecord::Base
  validates_presence_of :ssn, :if => :ssn_required?
end

describe "User" do
  it_should_validate_presence_of :ssn, :if => :ssn_required?
end

If the options passed to the assertion aren't used on the actual validation then the test will fail.

Ready to start rolling with this new hotness? test_spec_on_rails is now on Git so unless you're running Edge Rails you can't use script/install to grab it. My suggestion is to clone from Git into vendor/plugins and then svn:ignore the .git file:

git clone git://github.com/pelargir/test_spec_on_rails.git vendor/plugins/test_spec_on_rails
svn propset svn:ignore .git vendor/plugins/test_spec_on_rails

I noticed an interesting side effect of the default behavior of Rails today. A fresh Rails 2.0.2 app includes a line in app/controllers/application.rb that looks like this:

helper :all # include all helpers, all the time

It looks innocuous enough, but this line can actually cause some unexpected behavior when overriding Streamlined’s streamlined_top_menu and streamlined_side_menu helper methods on a controller-by-controller basis.

I had two Streamlined controllers setup, one for users and one for roles. I defined the users side menu and the roles side menu to each have certain links, like so:

# users_helper.rb
def streamlined_side_menu
   # stuff here
end

# roles_helper.rb
def streamlined_side_menu
  # different stuff here
end

When I visited the users controller, I saw the menu contents for the users controller. When I visited the roles controller, however, I saw the menu contents for… the users controller. What was happening was that ALL the helpers were being loaded for each controller, which meant that the streamlined_side_menu method defined in the roles helper got overridden by the users helper since the users helper was loaded after the roles helper.

Removing helper: all fixed the problem for me.

This is one of the reasons I’m doing mostly Rails consulting right now.

The problem I recently blogged about has been fixed in fixture_replacement2. Thanks, guys!