ansible/test/integration/targets/loop_control/inner.yml

- name: assert ansible_loop variables in include_tasks
  assert:
    that:
      - ansible_loop.index == ansible_loop.index0 + 1
      - ansible_loop.revindex == ansible_loop.revindex0 + 1
      - ansible_loop.first == {{ ansible_loop.index == 1 }}
      - ansible_loop.last == {{ ansible_loop.index == ansible_loop.length }}
      - ansible_loop.length == 3
      - ansible_loop.allitems|join(',') == 'first,second,third'