Testing https://stackoverflow.com/a/55142359/3787051

gistfile1.txt

# common.yaml:

---
service::common::httpd::packages: [ "Package['package-x']", "Package['package-y']" ]

# init.pp:

class test {
  package { 'package-x': ensure => installed }
  package { 'package-y': ensure => installed }
  $packages = lookup('service::common::httpd::packages')
  notify { 'message':
    require => $packages,
  }
}

# test case

describe 'test' do
  let(:hiera_config) { 'spec/fixtures/hiera/hiera.yaml' }
  it 'should compile' do
    is_expected.to compile
    File.write(
      'myclass.json',
      PSON.pretty_generate(catalogue)
    )
  end
end

Results:

Puppet 6.3

Failures:

  1) test should compile
     Failure/Error: is_expected.to compile
       error during compilation: Could not find resource 'Package['package-x']' in parameter 'require' (file: /Users/alexharvey/git/home/puppet-test/spec/fixtures/modules/test/manifests/init.pp, line: 7) on node alexs-macbook-pro.local
     # ./spec/classes/test_spec.rb:6:in `block (2 levels) in <top (required)>'

Interestingly it fails in a different way for Puppet 4.10.12 and 5.5.10:

Failures:

  1) test should compile
     Failure/Error: is_expected.to compile
       error during compilation: Could not retrieve dependency 'Package['package-x']' of Notify[message]
     # ./spec/classes/test_spec.rb:6:in `block (2 levels) in <top (required)>'

For both latest Puppet 6 and 4, the fix is the same, to remove the single quotes from the YAML.

Testing for Puppet 3 was too much trouble to set up. 
https://stackoverflow.com/a/55142359/3787051