community.general/test/integration/targets/template/corner_cases.yml

- name: test tempating corner cases
  hosts: localhost
  gather_facts: false
  vars:
    empty_list: []
    dont: I SHOULD NOT BE TEMPLATED
    other: I WORK
  tasks:
    - name: 'ensure we are not interpolating data from outside of j2 delmiters'
      assert:
        that:
            - '"I SHOULD NOT BE TEMPLATED" not in adjacent'
            - globals1 == "[[], globals()]"
            - globals2 == "[[], globals]"
      vars:
        adjacent: "{{ empty_list }} + [dont]"
        globals1: "[{{ empty_list }}, globals()]"
        globals2: "[{{ empty_list }}, globals]"

    - name: 'ensure we can add lists'
      assert:
        that:
            - (empty_list + [other]) == [other]
            - (empty_list + [other, other]) == [other, other]
            - (dont_exist|default([]) + [other]) == [other]
            - ([other] + [empty_list, other]) == [other, [], other]

    - name: 'ensure comments go away and we still dont interpolate in string'
      assert:
        that:
            - 'comm1 == " + [dont]"'
            - 'comm2 == " #} + [dont]"'
      vars:
        comm1: '{# {{nothing}} {# #} + [dont]'
        comm2: "{# {{nothing}} {# #} #} + [dont]"

    - name: test additions with facts, set them up
      set_fact:
        inames: []
        iname: "{{ prefix ~ '-options' }}"
        iname_1: "{{ prefix ~ '-options-1' }}"
      vars:
        prefix: 'bo'

    - name: add the facts
      set_fact:
        inames: '{{ inames + [iname, iname_1] }}'

    - assert:
        that:
            - inames == ['bo-options', 'bo-options-1']