More hardware-specific testing

Most of chefspec examples test whether recipes create various resources. While useful, don’t overlook that attribute files can also contain logic. This code is just as worthy of unit tests as recipes.

Say you have a recipe that configures the machine’s serial console. Using Chef::Util::FileEdit it manipulates /etc/inittab. Based on the hardware, it could be ttyS0 or ttyS1. And since VMs don’t have serial consoles, you don’t want to run agetty.

So you’ve split the logic up between attributes and the recipe. Given the following attributes file:

require 'chef/sugar'

default['console'].tap do |console|
  console['port'] = 'S1'
  console['baud'] = '115200'
  console['term'] = 'ansi'

  unless node.deep_fetch('virtualization', 'role').nil?
    # VMs don't have serial consoles
    console['port'] = nil
  end

  case node.deep_fetch('dmi', 'system', 'product_name')
  when 'PowerEdge M610', 'PowerEdge M710HD', 'PowerEdge M620'
    console['port'] = 'S0'
  end
end

There are five different paths through this code. The net result is three different values for node['console']['port']: S0, S1, and nil.

describe 'console::default' do
  CSH.each_hardware do |desc, ohai|
    context "on #{desc}" do
      let :runner do
        ChefSpec::Runner.new do |node|
          node.automatic.merge! ohai['automatic']
        end.converge(described_recipe)
      end

      it 'converges' do
        case desc
        when /_Guest$/
          expect(runner.node['console']['port']).to be_nil
        when /^PowerEdge_(M610|M710HD|M620)$/
          expect(runner.node['console']['port']).to eq('S0')
        else
          expect(runner.node['console']['port']).to eq('S1')
        end

        expect(runner.node['console']['baud']).to eq('115200')
        expect(runner.node['console']['term']).to eq('ansi')
      end
    end
  end
end

Now that the attributes have been verified, you can write spec tests for the recipe code.