Rails model default_value method conflict with presence true - ruby-on-rails

Question

I have this simplified model:
class Contract < ActiveRecord::Base
belongs_to :user belongs_to :plan
before_validation :set_default_is_voided
before_validation :set_default_expiration
validates :user, presence: true
validates :plan, presence: true
validates :contract_date, presence: true
validates :is_voided, presence: true
validates :expiration, presence: true
protected
def set_default_is_voided
if self.is_voided.nil?
self.is_voided = false
ap self.is_voided.present?
ap self.is_voided
end
end
def set_default_expiration
if self.contract_date.present?
self.expiration = self.contract_date+1.month
end
end
end
And this rspec simplified test:
context "Should create default values" do
it "Have to create is_voided" do
user = FactoryGirl.create(:user)
plan = FactoryGirl.create(:planContract)
ap "HERE"
contractDefault = FactoryGirl.create(:contractDefault, plan: plan, user: user)
ap contractDefault
expect(contractDefault.is_voided).to eq(false)
end
it "Have to create expiration" do
#expect(contract.expiration).should eq(Date.today()+1.month)
end
end
FactoryGirl:
FactoryGirl.define do
factory :contractVoid, class:Contract do
end
factory :contractDefault, class:Contract do
contract_date Date.today
end
end
This test fail with an 'is_voided can't be blank'.
And the question is:
Why the method "set_default_is_voided" in before_validation don't pass the presence true validation? Moreover, the self.is_voided.present? return false, why is it happing?

Answer 1

You answered your own question as to why set_default_is_voided doesn't pass the the presence: true validation, namely that self.is_voided.present? returns false, which is how presence: true is determined.
self.is_voided.present? returns false because false.present? == false per A concise explanation of nil v. empty v. blank in Ruby on Rails
See Rails: how do I validate that something is a boolean? for one way to validate that a boolean field is not nil.
See http://www.quora.com/Why-does-Rails-make-false-blank-true for a Q&A on the motivation behind the definition of blank?.