Consider the following:
ScheduledSession ------> Applicant <------ ApplicantSignup
Points to note:
- A ScheduledSession will exist in the system at all times; think of this as a class or course.
- The intent here is to validate the ApplicantSignup model against an attribute on ScheduledSession during
signups_controller#create
Associations
class ScheduledSession < ActiveRecord::Base
has_many :applicants, :dependent => :destroy
has_many :applicant_signups, :through => :applicants
#...
end
class ApplicantSignup < ActiveRecord::Base
has_many :applicants, :dependent => :destroy
has_many :scheduled_sessions, :through => :applicants
#...
end
class Applicant < ActiveRecord::Base
belongs_to :scheduled_session
belongs_to :applicant_signup
# TODO: enforce validations for presence
# and uniqueness constraints etc.
#...
end
SignupsController
Resources are RESTful, i.e. the #create action will have a path that's similar to /scheduled_sessions/:id/signups/new
def new
@session = ScheduledSession.find(params[:scheduled_session_id])
@signup = @session.signups.new
end
def create
@session = ScheduledSession.find(params[:scheduled_session_id])
@session.duration = (@session.end.to_time - @session.start.to_time).to_i
@signup = ApplicantSignup.new(params[:signup].merge(:sessions => [@session]))
if @signup.save
# ...
else
render :new
end
end
You'll notice I'm setting a virtual attribute above @session.duration to prevent Session from being considered invalid. The real 'magic' if you will happens in @signup = ApplicantSignup.new(params[:signup].merge(:sessions => [@session])) which now means that in the model I can select from self.scheduled_sessions and access the ScheduledSession this ApplicantSignup is being built against, even though at this very point in time, there is no record present in the join table.
Model validations for example look like
def ensure_session_is_upcoming
errors[:base] << "Cannot signup for an expired session" unless self.scheduled_sessions.select { |r| r.upcoming? }.size > 0
end
def ensure_published_session
errors[:base] << "Cannot signup for an unpublished session" if self.scheduled_sessions.any? { |r| r.published == false }
end
def validate_allowed_age
# raise StandardError, self.scheduled_sessions.inspect
if self.scheduled_sessions.select { |r| r.allowed_age == "adults" }.size > 0
errors.add(:dob_year) unless (dob_year.to_i >= Time.now.strftime('%Y').to_i-85 && dob_year.to_i <= Time.now.strftime('%Y').to_i-18)
# elsif ... == "children"
end
end
The above works quite well in development and the validations work as expected — but how does one test with with Factory Girl? I want unit tests to guarantee the business logic I've implemented after all — sure, this is after the fact but is still one way of going about TDD.
You'll notice I've got a commented out raise StandardError, self.scheduled_sessions.inspect in the last validation above — this returns [] for self.scheduled_sessions which indicates that my Factory setup is just not right.
One of Many Attempts =)
it "should be able to signup to a session" do
scheduled_session = Factory.build(:scheduled_session)
applicant_signup = Factory.build(:applicant_signup)
applicant = Factory.create(:applicant, :scheduled_session => scheduled_session, :applicant_signup => applicant_signup)
applicant_signup.should be_valid
end
it "should be able to signup to a session for adults if between 18 and 85 years" do
scheduled_session = Factory.build(:scheduled_session)
applicant_signup = Factory.build(:applicant_signup)
applicant_signup.dob_year = 1983 # 28-years old
applicant = Factory.create(:applicant, :scheduled_session => scheduled_session, :applicant_signup => applicant_signup)
applicant_signup.should have(0).error_on(:dob_year)
end
The first one passes, but I honestly do not believe it's properly validating the applicant_signup model; the fact that self.scheduled_sessions is returning [] simply means that the above just isn't right.
It's quite possible that I'm trying to test something outside the scope of Factory Girl, or is there a far better approach to tackling this? Appreciate all comments, advice and constructive criticism!
Updates:
- Not sure what this is called but this is the approach taken at least with regards to how it's implemented at the controller level
- I need to consider ignoring Factory Girl for the association aspect at least and attempt to return the
scheduled_sessionby mockingscheduled_sessionson theapplicant_signupmodel.
Factories
FactoryGirl.define do
factory :signup do
title "Mr."
first_name "Franklin"
middle_name "Delano"
last_name "Roosevelt"
sequence(:civil_id) {"#{'%012d' % Random.new.rand((10 ** 11)...(10 ** 12))}"}
sequence(:email) {|n| "person#{n}@#{(1..100).to_a.sample}example.com" }
gender "male"
dob_year "1980"
sequence(:phone_number) { |n| "#{'%08d' % Random.new.rand((10 ** 7)...(10 ** 8))}" }
address_line1 "some road"
address_line2 "near a pile of sand"
occupation "code ninja"
work_place "Dharma Initiative"
end
factory :session do
title "Example title"
start DateTime.civil_from_format(:local,2011,12,27,16,0,0)
duration 90
language "Arabic"
slides_language "Arabic & English"
venue "Main Room"
audience "Diabetic Adults"
allowed_age "adults"
allowed_gender "both"
capacity 15
published true
after_build do |session|
# signups will be assigned manually on a per test basis
# session.signups << FactoryGirl.build(:signup, :session => session)
end
end
factory :applicant do
association :session
association :signup
end
#...
end
