community.general/test/integration/targets/lookup_inventory_hostnames/main.yml

---
- hosts: localhost
  gather_facts: no
  tasks:
  - set_fact:
      hosts_a: "{{ lookup('inventory_hostnames', 'group01', wantlist=true) }}"

  - set_fact:
      hosts_b: "{{ groups['group01'] }}"

  - assert:
      that:
        - hosts_a == hosts_b