```ruby
require 'test_helper'

class UserTest < ActiveSupport::TestCase
  def setup
    @user = User.new(name: 'Example user', email: 'example@example.com')
  end

  test 'should be valid' do
    assert @user.valid?
  end

  test 'name should be present' do
    @user.name = '     '
    assert_not @user.valid?
  end
end
```

Add test case for user's email presence
user
```ruby
require 'test_helper'

class UserTest < ActiveSupport::TestCase
  def setup
    @user = User.new(name: 'Example user', email: 'example@example.com')
  end

  test 'should be valid' do
    assert @user.valid?
  end

  test 'name should be present' do
    @user.name = '     '
    assert_not @user.valid?
  end

  test 'email should be present' do
    @user.email = ' '
    assert_not @user.valid?
  end
end
```
assistant