module ActiveModel::Lint::Tests

object will route to the update action.
will route to the create action. If it is persisted, a form for the
If the object is not persisted, a form for that object, for instance,
persisted? is used when calculating the URL for an object.

calling this method returns either +true+ or +false+. Fails otherwise.
Passes if the object's model responds to persisted? and if

def test_persisted?
  assert model.respond_to?(:persisted?), "The model should respond to persisted?"
  assert_boolean model.persisted?, "persisted?"
end