or_else_what.rb

class Object
  def or_else
    self
  end
end

class NilClass
  def or_else
    yield
  end
end

or_else_what_spec.rb

RSpec.describe OrElseWhat do
  describe 'nil.or_else { value }' do
    it 'returns the value' do
      expect(nil.or_else { 'chicken' }).to eq('chicken')
    end
  end

  describe 'false.or_else { value }' do
    it 'returns false' do
      expect(false.or_else { 'chicken' }).to be(false)
    end
  end
end