ansible/test/integration/targets/lookup_together/tasks/main.yml

- name: test with_together
  #shell: echo {{ item }}
  set_fact: "{{ item.0 }}={{ item.1 }}"
  with_together:
    - [ 'a', 'b', 'c', 'd' ]
    - [ '1', '2', '3', '4' ]

- name: verify with_together results
  assert:
    that:
        - "a == '1'"
        - "b == '2'"
        - "c == '3'"
        - "d == '4'"

- block:
    - name: "EXPECTED FAILURE - test empty list"
      debug:
        msg: "{{ item.0 }} and {{ item.1 }}"
      with_together: []

    - fail:
        msg: "should not get here"

  rescue:
    - assert:
        that:
          - ansible_failed_task.name == "EXPECTED FAILURE - test empty list"
          - ansible_failed_result.msg == "with_together requires at least one element in each list"