RSpec Test Patterns

test_file_existance.rb

# Test the existance of a file after a method call
it('will create a file') do
  expect { subject.create_the_file }.to change { File.exists? my_file }.from(false).to(true)
end

test_private_method.rb

it('will do something') do
  expect { subject.instance_eval { my_private_method } }.to be_true
end