user_spec.rb

require 'spec_helper'

describe User do
  it "has a valid factory" do
    build(:user).should be_valid
  end

  it "is invalid without an email" do
    build(:user, email: nil).should_not be_valid
  end

  it "is invalid if the username is shorter than 3 characters" do 
    build(:user, username: 'ln').should_not be_valid
  end

  it "is invalid if password is shorter than 6 characters" do
    build(:user, password: '12345', password_confirmation: '12345').should_not be_valid
  end

  it "is invalid if password doesn't match" do
    build(:user, password: 'test123', password_confirmation: 'test321').should_not be_valid
  end

  it "is invalid if username is not unique" do
    create(:user, username: 'ellen.u').should be_valid
    create(:user, username: 'ellen.u').should be_valid
  end

  it "is invalid if email is not unique" do
    create(:user, email: '[email protected]').should be_valid
    create(:user, email: '[email protected]').should be_valid
  end
end

users.rb

require 'faker'
FactoryGirl.define do
  factory :user do 
    email {Faker::Internet.email}
    username {Faker::Internet.user_name}
    first_name {Faker::Name.first_name}
    last_name {Faker::Name.last_name}
    password 'test123'
    password_confirmation 'test123'
  end
end