community.general/test/integration/test_hosts_field.yml

---
#- name: Host in playbook is an integer
#  hosts: 42
#  tags: numeric_host
#  tasks:
#    - command: echo 'Running on {{ inventory_hostname }}'

#- name: Host in playbook is a string of digits
#  hosts: "42"
#  tags: string_digit_host
#  tasks:
#    - command: echo 'Running on {{ inventory_hostname }}'

#- name: Host in playbook is a list of integer
#  hosts:
#    - 42
#  tags: numeric_host_in_list
#  tasks:
#    - command: echo 'Running on {{ inventory_hostname }}'

- name: Host in playbook is a list of strings of digits
  hosts:
    - "42"
  gather_facts: False
  tags: string_digit_host_in_list
  tasks:
    - command: echo 'Running on {{ inventory_hostname }}'

- name: Hosts taken from kv extra_var on the CLI
  hosts: "{{ target_kv }}"
  gather_facts: False
  tags: hosts_from_kv_string
  tasks:
    - command: echo 'Running on {{ inventory_hostname }}'

- name: Hosts taken from a json string on the CLI
  hosts: "{{ target_json_cli }}"
  gather_facts: False
  tags: hosts_from_cli_json_string
  tasks:
    - command: echo 'Running on {{ inventory_hostname }}'

- name: Hosts taken from a json list on the CLI
  hosts: "{{ target_json_cli_list }}"
  gather_facts: False
  tags: hosts_from_cli_json_list
  tasks:
    - command: echo 'Running on {{ inventory_hostname }}'

- name: Hosts is taken from a json string in an extra_vars file
  hosts: "{{ target_json_file }}"
  gather_facts: False
  tags: hosts_from_json_file_string
  tasks:
    - command: echo 'Running on {{ inventory_hostname }}'

- name: Hosts is taken from a json list in an extra_vars file
  hosts: "{{ target_json_file_list }}"
  gather_facts: False
  tags: hosts_from_json_file_list
  tasks:
    - command: echo 'Running on {{ inventory_hostname }}'