Scope that only returns users who are 21 or older

spec_results.txt

Failures:

  1) User scopes .adult_purchases_enabled does not return users who are not at least 21 years old
     Failure/Error: User.adult_purchases_enabled.should_not include(subject)
       expected [#<User id: 338, first_name: "Romaine", last_name: "Mohr", address1: "87010 Derick Heights", address2: nil, city: "Welchton", state: "Arkansas", zip_code: "11561", avatar: nil, birth_date: "1993-08-06", email: "foo-16@bar.com", about: nil, created_at: "2013-08-06 13:31:54", updated_at: "2013-08-06 13:31:55", latitude: 40.5895, longitude: -73.6389, active: false>] not to include #<User id: 338, first_name: "Romaine", last_name: "Mohr", address1: "87010 Derick Heights", address2: nil, city: "Welchton", state: "Arkansas", zip_code: "11561", avatar: nil, birth_date: "1993-08-06 00:00:00", email: "foo-16@bar.com", about: nil, created_at: "2013-08-06 13:31:54", updated_at: "2013-08-06 13:31:55", latitude: 40.5895272, longitude: -73.6389038, active: false>
       Diff:
       @@ -1,2 +1,2 @@
       -[#<User id: 338, first_name: "Romaine", last_name: "Mohr", address1: "87010 Derick Heights", address2: nil, city: "Welchton", state: "Arkansas", zip_code: "11561", avatar: nil, birth_date: "1993-08-06 00:00:00", email: "foo-16@bar.com", about: nil, created_at: "2013-08-06 13:31:54", updated_at: "2013-08-06 13:31:55", latitude: 40.5895272, longitude: -73.6389038, active: false>]
       +[#<User id: 338, first_name: "Romaine", last_name: "Mohr", address1: "87010 Derick Heights", address2: nil, city: "Welchton", state: "Arkansas", zip_code: "11561", avatar: nil, birth_date: "1993-08-06", email: "foo-16@bar.com", about: nil, created_at: "2013-08-06 13:31:54", updated_at: "2013-08-06 13:31:55", latitude: 40.5895, longitude: -73.6389, active: false>]
       
     # ./spec/models/user_spec.rb:80:in `block (4 levels) in <top (required)>'

  2) User scopes .adult_purchases_enabled returns users who are at least 21 years old
     Failure/Error: User.adult_purchases_enabled.should include(subject)
       expected [] to include #<User id: 339, first_name: "Romaine", last_name: "Mohr", address1: "87010 Derick Heights", address2: nil, city: "Welchton", state: "Arkansas", zip_code: "11561", avatar: nil, birth_date: "1992-08-06 00:00:00", email: "foo-17@bar.com", about: nil, created_at: "2013-08-06 13:31:55", updated_at: "2013-08-06 13:31:55", latitude: 40.5895272, longitude: -73.6389038, active: false>
       Diff:
       @@ -1,2 +1,2 @@
       -[#<User id: 339, first_name: "Romaine", last_name: "Mohr", address1: "87010 Derick Heights", address2: nil, city: "Welchton", state: "Arkansas", zip_code: "11561", avatar: nil, birth_date: "1992-08-06 00:00:00", email: "foo-17@bar.com", about: nil, created_at: "2013-08-06 13:31:55", updated_at: "2013-08-06 13:31:55", latitude: 40.5895272, longitude: -73.6389038, active: false>]
       +[]
       
     # ./spec/models/user_spec.rb:86:in `block (4 levels) in <top (required)>'

Finished in 11.66 seconds
34 examples, 2 failures

Failed examples:

rspec ./spec/models/user_spec.rb:77 # User scopes .adult_purchases_enabled does not return users who are not at least 21 years old
rspec ./spec/models/user_spec.rb:83 # User scopes .adult_purchases_enabled returns users who are at least 21 years old

user.rb

class User < ActiveRecord::Base
  # ...
  scope :adult_purchases_enabled, -> { where('birth_date >= ?', 21.years.ago.midnight) }
  # ...
end

user_spec.rb

describe User do
  let(:user) { FactoryGirl.create(:valid_user) }
  subject { user }
  # ...
  describe '.adult_purchases_enabled' do
    it 'does not return users who are not at least 21 years old' do
      subject.birth_date = 20.years.ago.midnight
      subject.save!
      User.adult_purchases_enabled.should_not include(subject)
    end
  
    it 'returns users who are at least 21 years old' do
      subject.birth_date = 21.years.ago.midnight
      subject.save!
      User.adult_purchases_enabled.should include(subject)
    end
  end
  # ...
end