Rspec and FactoryGirl Uniqueness Failing - ruby

Question

I'll be brief with the code samples, as all of my tests pass except the one below. I got it to pass by changing things up a bit, but I'm not sure why version 1 fails and version 2 works.
My model:
# app/models/person.rb
class Person
validates :contact_number, uniqueness: true
end
Model spec
# spec/models/person_spec.rb
require 'spec_helper'
describe Person do
it 'is a valid factory' do
create(:person).should be_valid # passes
end
it 'has a unique phone number' do
create(:person)
build(:person).should_not be_valid # fails
end
it 'also has a unique phone number' do
person1 = create(:person)
person2 = person1.dup
person2.should_not be_valid # passes
end
end
As far as I can tell, the two uniqueness tests should be doing the same thing, however one passes and one fails.
If it matters, I am using mongoid, though I don't think that should have any effect. I'm also not doing anything with nested contexts or describes in my test, so I think the scope is correct. Any insight is appreciated.
UPDATE 1: I realized in my factory I am adding an initialize_with block like this:
initialize_with { Person.find_or_create_by(contact_number: contact_number) }
I realized that this may be the reason the validation was failing -- I was just getting the same person back. However, commenting out that line gives the following error:
Mongoid::Errors::Validations:
Problem:
Validation of Person failed.
Summary:
The following errors were found: Contact number is already taken
Resolution:
Try persisting the document with valid data or remove the validations.
Which, in theory is good, I suppose, since it won't let me save a second person with the same contact number, but I'd prefer my test to pass.

Answer 1

Probably your person factory has a sequence in contact_number making a diferent contact_number in each person.
Just realize that the build(:person) doesnt validate. The validation occurs only in create.
I strongly suggest use of shoulda-matchers for this kind of validations.

Answer 2

It is possible that your database is being cleaned (do you have database-cleaner in your Gemfile), or your tests are not being run in the order you think they are. (Check for :random in your spec_helper.rb)
While the above answer regarding using shoulda-matchers will help you run this particular test in RSpec more concisely, you probably want to have your unique phone number test be able to be run completely on its own without relying on another spec having executed. Your second test is an example of Obscure Test (and also a little bit of Mystery Guest http://robots.thoughtbot.com/mystery-guest), where it's not clear from the test code what is actually being tested. Your phone number parameter is defined in another file (the factory), and the prior data setup is being run in another spec somewhere else in the file.
Your second test is already better because it is more explicitly showing what you're testing, and doesn't rely on another spec having been run. I would actually write it like this to make it more explicit:
it 'has a unique phone number' do
person1 = create(:person, phone_number: '555-123-4567')
person2 = create(:person, phone_number: '555-123-4567')
# can use 'should' here instead
expect(person2).not_to be_valid
end
If you don't explicitly make it about the phone number, then if you change your factory this test might start failing even though your code is still sound. In addition, if you have other attributes for which you are validating uniqueness, your previous test might pass even though the phone number validation is missing.

Answer 3

I figured it out! On a whim, I checked out the test database and noticed that a Person object was lingering around. So, it actually wasn't the
build(:person).should_not be_valid that was raising the Mongoid exception. It was the create call on the line before. Clearing out the DB and running the spec again passed, but again the data was persisting. I double checked my spec_helper.rb file and noticed I wasn't calling start on the DatabaseCleaner. My updated spec_helper.rb file looks like this, and now everything works:
# Clean up the database
require 'database_cleaner'
config.mock_with :rspec
config.before(:suite) do
DatabaseCleaner.strategy = :truncation
DatabaseCleaner.orm = "mongoid"
end
config.before(:each) do
DatabaseCleaner.start
end
config.after(:each) do
DatabaseCleaner.clean
end