```ruby
require 'test_helper'

class CartItemTest < ActiveSupport::TestCase
  # test "the truth" do
  #   assert true
  # end
end
```

Add tests for CartItem model
user
```ruby
require 'test_helper'

class CartItemTest < ActiveSupport::TestCase
  test "CartItem Weight should match" do
    assert_equal 200, cart_items(:george_one).weight
  end

  test "CartItem cost should match" do
    assert_equal 49.9, cart_items(:george_one).cost
  end
end
```
assistant