[SOLVED] for what reason is the string constantly inserted at the end of the file?

for what reason is the string constantly inserted at the end of the file?

I want to insert a line with a user test999 before a construction site with a user test3 .I can't insert a line before another one, it is constantly inserted into the last one, for what reason can this happen?

---
- hosts: app_stage
  become: yes
  vars:
    user: test999
  tasks:
    - name: remove immutable
      file:
        path: /etc/sudoers
        attr: '-i'
    - name: change permission
      file:
        path: /etc/sudoers
        mode: 0660
    - name: Allow ‘user’ to have passwordless sudo
      lineinfile:
        dest: /etc/sudoers
        state: present
        regexp: '^test3 ALL=(ALL) NOPASSWD: ALL'
        insertbefore: '^test3 ALL=(ALL) NOPASSWD: ALL'
        line: '{{ user }} ALL=(ALL) NOPASSWD: ALL'
        validate: visudo -cf %s
    - name: change permissions back
      file:
        path: /etc/sudoers
        mode: 0440
        owner: root
        group: root
    - name: back immutable
      file:
        path: /etc/sudoers
        attr: '+i'

Solution

Check the lineinfile module documentation for insertbefore:

Used with state=present

If specified regular expression has no matches, the line will be inserted at the end of the file.

If regular expressions are passed to both regexp and insertbefore, insertbefore is only honored if no match for regexp is found.