```ruby
# # encoding: utf-8

# Inspec test for recipe universe-ubuntu::default

# The Inspec reference, with examples and extensive documentation, can be
# found at https://docs.chef.io/inspec_reference.html

unless os.windows?
  describe user('root') do
    it { should exist }
    skip 'This is an example test, replace with your own test.'
  end
end

describe port(80) do
  it { should_not be_listening }
  skip 'This is an example test, replace with your own test.'
end
```

Add test on installed packages
user
```ruby
# # encoding: utf-8

# Inspec test for recipe universe-ubuntu::default

# The Inspec reference, with examples and extensive documentation, can be
# found at https://docs.chef.io/inspec_reference.html

packages = %w(golang
              libjpeg-turbo8-dev
              make
              tmux
              htop
              chromium-browser
              git
              cmake
              zlib1g-dev
              libjpeg-dev
              xvfb
              libav-tools
              xorg-dev
              python-opengl
              libboost-all-dev
              libsdl2-dev
              swig)
              
packages.each do |item|
  describe package item do
    it { should be_installed }
  end
end
```
assistant