Capybara: How to find a hidden field by its label

To find an input with the type hidden, you need to specify the type hidden:

Copyfind_field('Some label', type: :hidden)

Otherwise you will see an exception :

Copyfind_field('Some label')
# => Capybara::ElementNotFound: Unable to find field "Some label" that is not disabled`.

Note: Usually you don't need to check the input of hidden fields in an integration test. But e.g. waiting for a datepicker library to write the expected value to this field before continuing the test, which prevents flaky tests, is a valid use case.