See also https://github.com/DavidS/david-testmod/commit/d2c3db5a7f5f4d821a5a48573df1c4154154c23a

lib-puppet-type-file_test.rb

require 'puppet/resource_api'

Puppet::ResourceApi.register_type(
  name: 'file_test',
  docs: <<-EOS,
      This type provides Puppet with the capabilities to manage ...
    EOS
  features: [],
  title_patterns: [
    {
      pattern: %r{^(?<target>.*)#(?<key>[^#]*)$},
      desc: 'Provide the target and the key in one piece, separated with a hash (`#`). For example: `/etc/puppet/puppet.conf#noop` ',
    },
  ],
  attributes:   {
    ensure:      {
      type:    'Enum[present, absent]',
      desc:    'Whether this resource should be present or absent on the target system.',
      default: 'present',
    },
    target:        {
      type:      'String',
      desc:      'The file containing the record.',
      behaviour: :namevar,
    },
    key:        {
      type:      'String',
      desc:      'The key of the record.',
      behaviour: :namevar,
    },
    value:        {
      type:      'String',
      desc:      'The value of the record.',
    },
  },
)

usage

david@davids:~/git/david-testmod$ bundle exec puppet resource --modulepath ./spec/fixtures/modules/ file_test "/etc/puppet/puppet.conf#noop" 
file_test { '/etc/puppet/puppet.conf#noop': 
  ensure => 'absent',
  target => '/etc/puppet/puppet.conf',
  key => 'noop',
}
david@davids:~/git/david-testmod$