Add test plugin which allows to query whether a module or action plugin is available (#3628)

* Add test which allows to query whether an action is available.

* Add documentation.

* Fix FreeBSD / macOS compatibility.

* Rename an_action -> a_module.

* Forgot one place.

tests/integration/targets/test_a_module/aliases

@@ -0,0 +1 @@
+shippable/posix/group3

tests/integration/targets/test_a_module/collections/ansible_collections/testns/testcoll/galaxy.yml

@@ -0,0 +1,7 @@
+namespace: testns
+name: testcoll
+version: 0.0.1
+authors:
+  - Ansible (https://github.com/ansible)
+description: null
+tags: [community]

tests/integration/targets/test_a_module/collections/ansible_collections/testns/testcoll/plugins/modules/collection_module.py

@@ -0,0 +1,32 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# (c) 2021, Felix Fontein <felix@fontein.de>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+DOCUMENTATION = '''
+---
+module: collection_module
+short_description: Test collection module
+description:
+  - This is a test module in a local collection.
+author: "Felix Fontein (@felixfontein)"
+options: {}
+'''
+
+EXAMPLES = ''' # '''
+
+RETURN = ''' # '''
+
+from ansible.module_utils.basic import AnsibleModule
+
+
+def main():
+    AnsibleModule(argument_spec={}).exit_json()
+
+
+if __name__ == '__main__':
+    main()

tests/integration/targets/test_a_module/library/local_module.py

@@ -0,0 +1,32 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# (c) 2021, Felix Fontein <felix@fontein.de>
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+DOCUMENTATION = '''
+---
+module: local_module
+short_description: Test local module
+description:
+  - This is a test module locally next to a playbook.
+author: "Felix Fontein (@felixfontein)"
+options: {}
+'''
+
+EXAMPLES = ''' # '''
+
+RETURN = ''' # '''
+
+from ansible.module_utils.basic import AnsibleModule
+
+
+def main():
+    AnsibleModule(argument_spec={}).exit_json()
+
+
+if __name__ == '__main__':
+    main()

tests/integration/targets/test_a_module/runme.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+set -eux
+
+export ANSIBLE_TEST_PREFER_VENV=1  # see https://github.com/ansible/ansible/pull/73000#issuecomment-757012395; can be removed once Ansible 2.9 and ansible-base 2.10 support has been dropped
+source virtualenv.sh
+
+# The collection loader ignores paths which have more than one ansible_collections in it.
+# That's why we have to copy this directory to a temporary place and run the test there.
+
+# Create temporary folder
+TEMPDIR=$(mktemp -d)
+trap '{ rm -rf ${TEMPDIR}; }' EXIT
+
+cp -r . "${TEMPDIR}"
+cd "${TEMPDIR}"
+
+ansible-playbook runme.yml "$@"

tests/integration/targets/test_a_module/runme.yml

@@ -0,0 +1,25 @@
+- hosts: localhost
+  tasks:
+    - name: Test a_module
+      assert:
+        that:
+          # Modules/actions that do not exist
+          - "'foo_bar' is not community.general.a_module"
+          - "'foo.bar.baz' is not community.general.a_module"
+          # Short name and FQCN for builtin and other collections
+          - "'file' is community.general.a_module"
+          - "'set_fact' is community.general.a_module"
+          - "'ansible.builtin.file' is community.general.a_module"
+          - "'ansible.builtin.set_fact' is community.general.a_module"
+          - "'ansible.builtin.foo_bar' is not community.general.a_module"
+          - "'community.crypto.acme_certificate' is community.general.a_module"
+          - "'community.crypto.openssl_privatekey_pipe' is community.general.a_module"
+          - "'community.crypto.foo_bar' is not community.general.a_module"
+          # Modules from this collection (that exist or not)
+          - "'community.general.ufw' is community.general.a_module"
+          - "'community.general.foooo_really_does_not_exist' is not community.general.a_module"
+          # Local module
+          - "'local_module' is community.general.a_module"
+          # Local collection module (that exist or not)
+          - "'testns.testcoll.collection_module' is community.general.a_module"
+          - "'testns.testcoll.foobar' is not community.general.a_module"