Using nested context blocks in rspec

spreadsheet_validator_spec.rb

class SpreadsheetValidator
  def initialize(spreadsheet_reader)
    @reader = spreadsheet_reader
    @errors = []
  end

  def has_errors?
    @errors.length > 0
  end

  def validate
    @reader.rows.each do |row|
      if !['Hired', 'Rejected'].include?(row[:status])
        @errors << "Invalid Status '#{row[:status]}'"
      end
    end
  end
end

describe SpreadsheetValidator do
  let(:reader) { double }
  let(:rows) { [] }
  let(:valid_row) do
    {
      :id => 42,
      :first_name => 'George',
      :last_name => 'Costanza',
      :company => 'Vandelay Industries',
      :title => 'Latex Salesman',
      :status => 'Hired'
    }
  end
  subject { SpreadsheetValidator.new(reader) }

  before do
    allow(reader).to receive(:rows).and_return(rows)
  end

  describe 'validate' do
    context 'with valid rows' do
      let(:rows) { [ valid_row ] }

      it 'should not have errors' do
        subject.validate
        expect(subject.has_errors?).to eq(false)
      end
    end

    context 'with invalid status' do
      let(:rows) { [ valid_row.merge(:status => 'some bullshit status') ] }

      it 'should have errors' do
        subject.validate
        expect(subject.has_errors?).to eq(true)
      end
    end
  end
end