I have a simple test for the nginx cookbook:
require 'spec_helper'
describe 'my_cookbook::nginx' do
  let(:chef_run) do
    ChefSpec::Runner.new do |node|
      node.set['nginx']['dir'] = '/etc/nginx'
    end.converge(described_recipe)
  end
  it 'should create configuration directory' do
    expect(chef_run).to create_directory("#{node['nginx']['dir']}")
  end
end
Which is failing:
Failures:
  1) my_cookbook::nginx should create configuration directory
     Failure/Error: expect(chef_run).to create_directory("#{node['nginx']['dir']}")
     NameError:
       undefined local variable or method `node' for #<RSpec::Core::ExampleGroup::Nested_1:0x00000007993570>
I'm attempting to set the node attributes as described in the docs, is there something obvious I'm missing?