bdd

I've been having a lot of fun the last couple days doing Behaviour Driven Development (BDD) with test/spec on that new Personal Training online site that I'm coding in Ruby on Rails.

I first setup a User class, modifying the User class generated by acts_as_authenticated.

Then, I added Trainer and Client classes that use a polymorphic association to subclass the User class. It was a little strange, I first was thinking about using Single Table Inheritance (STI), but I figured that the Trainer and Client classes are sufficiently different from each other to warrant their own classes.

If I used STI, I would have had to put all the data for both the Trainer and the Client into the User model. These two roles are quite different, for example, a Trainer would receive a monthly invoice from us, but a Client would receive a monthly invoice from the Trainer. With STI, things could get pretty complicated, so I'm going to try polymorphic associations for now.

To do those polymorphic association for the User, I added a role_id and role_type fields to the model, and :polymorphic to the :belongs_to

#  role_id                   :integer(11)
#  role_type                 :string(255)
class User < ActiveRecord::Base
  belongs_to :role, :polymorphic => true
end

Added the "has_one :user" and the "has_many :clients" to the Trainer:

class Trainer < ActiveRecord::Base

  has_one :user, :as => :role
  has_many :clients

end

and added the "has_one :user" and "belongs_to :trainer" to the Client:

class Client < ActiveRecord::Base

  has_one :user, :as => :role
  belongs_to :trainer

end

Then, I wrote a whole bunch of specifications to test everything backward and forward. Here's the test for the Client class, the Trainer class is almost identical:

  context "" do

    fixtures :trainers
    fixtures :clients
    fixtures :users

    setup do
      # Trainers
      @deryn = trainers(:deryn)
      @gordo = trainers(:gordo)
      # Clients
      @sness = clients(:sness)
      @matt = clients(:matt)
      @melissa = clients(:melissa)
    end

    specify "Client and User should be easy to create and link together" do
      t = Client.new
      u = User.new
      u.login = "userlogin"
      u.role = t
      u.save_without_validation
      u.role.should.be t
      t.user.should.equal u
    end

    specify "Client should be able to be associated with a User" do
      @matt.user.should.equal users(:matt)
    end

    specify "Client should be associated with a trainer" do
      @matt.trainer.should.equal @deryn
      @sness.trainer.should.equal @deryn
      @melissa.trainer.should.equal @gordo
    end

    specify "Should be able to add a Trainer to a Client" do
      c = Client.new
      c.trainer = @deryn
      c.save
      @deryn.clients.length.should.equal 3
    end



  end