ansible/test/integration/targets/blockinfile/tasks/create_dir.yml

- name: Set up a directory to test module error handling
  file:
    path: "{{ remote_tmp_dir_test }}/unreadable"
    state: directory
    mode: "000"

- name: Create a directory and file with blockinfile
  blockinfile:
    path: "{{ remote_tmp_dir_test }}/unreadable/createme/file.txt"
    block: |
      line 1
      line 2      
    state: present
    create: yes
  register: permissions_error
  ignore_errors: yes

- name: assert the error looks right
  assert:
    that:
      - permissions_error.msg.startswith('Error creating')
  when: "ansible_user_id != 'root'"

- name: otherwise (root) assert the directory and file exists
  stat:
    path: "{{ remote_tmp_dir_test }}/unreadable/createme/file.txt"
  register: path_created
  failed_when: path_created.exists is false
  when: "ansible_user_id == 'root'"