ansible/test/integration/targets/systemd/tasks/test_mask.yml

- name: Copy service file for mask operation
  template:
    src: mask_me.service
    dest: /etc/systemd/system/mask_me.service
    owner: root
    group: root
    mode: '0644'
  notify: remove unit file

- name: Reload systemd
  systemd:
    daemon_reload: true

- name: Try to mask already masked service
  systemd:
    name: mask_me.service
    masked: true
  register: mask_test_1
  ignore_errors: true

- name: Test mask service test
  assert:
    that:
      - mask_test_1 is not changed
      - "'Failed to mask' in mask_test_1.msg"