Configure ChefSolo and specify platform on default_spec.rb

default_spec.rb

require 'spec_helper'

describe 'cookbook::default' do
  context 'When applying cookbooks on an Ubuntu instance' do
    let(:chef_run) do
      runner = ChefSpec::SoloRunner.new(platform: 'ubuntu', version: '16.04')
      runner.converge(described_recipe)
    end

    it 'converges successfully' do
      expect { chef_run }.to_not raise_error
    end
  end
end