Api::CompatibilityChecker#check_create_host_nested iterates over nested attributes in a params hash and should work for both arrays and hash styles of nested attrs, but it does so using a single each call yielding a single argument.

This works on Rails 4 where ActionController::Parameters inherits each from a Hash, as an array of [key, value] would be yielded instead, which the block checks for (attribute[1] if attribute.is_a?(Array)).

In Rails 5.0, AC::Parameters has its own each implementation that only yields to two arguments. Using each do |attribute| will instead be yielded only the key name. This causes:

Api::V2::HostsControllerTest#test_0010_should create host with host_parameters_attributes sent in a hash [test/controllers/api/v2/hosts_controller_test.rb:186]:
"Host.count" didn't change by 1.
Expected: 2
  Actual: 1

The iteration should be handled differently for arrays and AC::Parameters/hashes.