Rails 3.1, RSpec: testing model validations

Question

I have started my journey with TDD in Rails and have run into a small issue regarding tests for model validations that I can\'t seem to find a solution to. Let\'s say I have a U

Answer 1

A little late to the party here, but if you don't want to add shoulda matchers, this should work with rspec-rails and factorybot:

# ./spec/factories/user.rb
FactoryBot.define do
  factory :user do
    sequence(:username) { |n| "user_#{n}" }
  end
end

# ./spec/models/user_spec.rb
describe User, type: :model do
  context 'without a username' do
    let(:user) { create :user, username: nil }

    it "should NOT be valid with a username error" do
      expect(user).not_to be_valid
      expect(user.errors).to have_key(:username)
    end
  end
end