RSpec fails when using custom validator

Question

I am using such kind of validation in my rails 3.1 project.

validates_presence_of :sales_price
validates_presence_of :retail_price
validates_numericality_of :sales_price, :greater_than => 0,
                          :allow_blank => true
validates_numericality_of :retail_price, :greater_than => 0,
                          :allow_blank => true

validate :sales_price_less_than_retail

def sales_price_less_than_retail
  if sales_price >= retail_price
    errors.add(:sales_price, "must be less than retail price.")
  end
end

I'm testing models using rspec. Everything was ok when i used only rails standard validation helpers. But when i wrote custom validator(sales_price_less_than_retail) tests started to fail.

Here is the code of the test:

it { should validate_presence_of :sales_price }
it { should validate_presence_of :retail_price }
it { should validate_numericality_of :sales_price }
it { should validate_numericality_of :retail_price }

Here is the factory:

Factory.define :offer_option do |f|
  f.sales_price          rand(21) + 10  # $10-$30
  f.retail_price         { |a| a.sales_price * 2 }
end

When i run the test i get such errors:

Failures:

1) OfferOption

Failure/Error: it { should validate_presence_of :sales_price }
 NoMethodError:
   undefined method `>=' for nil:NilClass
 # ./app/models/offer_option.rb:38:in `sales_price_less_than_retail'
 # ./spec/models/offer_option_spec.rb:18:in `block (2 levels) in <top (required)>'

2) OfferOption

 Failure/Error: it { should validate_presence_of :retail_price }
 ArgumentError:
   comparison of BigDecimal with nil failed
 # ./app/models/offer_option.rb:38:in `>='
 # ./app/models/offer_option.rb:38:in `sales_price_less_than_retail'
 # ./spec/models/offer_option_spec.rb:19:in `block (2 levels) in <top (required)>'

I guess everything should be ok because rspec should test validators separately, but it seems that it calls custom validator after calling validates_presence_of in my test. The problem disappears when i remove custom validator.

What am I doing wrong?

sparrovv · Accepted Answer · 2011-11-14 13:06:28Z

7

I assume that this is because validate_presence_of rspec helper set offer_option.sales_price = nil and then call valid? on offer_option. When calling valid?, it runs all your validations, so your custom validation as well. And then you get this error, cause there is no '>=' method on nil.

if you change sales_price_less_than_retail to:

def sales_price_less_than_retail
  return if sales_prices.blank? || retail_price.blank?

  if sales_price >= retail_price
    errors.add(:sales_price, "must be less than retail price.")
  end 
end

Then it should works.

edited Nov 14, 2011 at 13:06

answered Nov 14, 2011 at 12:05

sparrovv

7,8843 gold badges32 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Peter Brown Over a year ago

I don't think this would work if the sales_price or retail_price were set to empty strings from a form input. You would need to check if they were present. I will usually return from the method if the conditions aren't met rather than having a long chain of conditionals. return if sales_price.blank? || retail_price.blank?

sparrovv Over a year ago

True, I need to improve my example

JerryA Over a year ago

Thanks for this! Although this seems like a hack, is there something fundamentaly wrong with how we are writing out test?

Collectives™ on Stack Overflow

RSpec fails when using custom validator

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related