A Rails model test "hello world"

What we’re going to do in this post is:Initialize a new Rails applicationInstall RSpec using the rspec-rails gemGenerate a User modelWrite a single test for that User modelThe test we’ll write will be a trivial one. The user will have both a first and last name. On the User model we’ll define a full_name method that concatenates first and last name. Our test will verify that this method works properly. Let’s now begin the first step, initializing the Rails application.