Add integration tests for basic.py _set_cwd.

These tests verify that AnsibleModule can be instantiated when cwd does not exist or is unreadable.

test/integration/targets/module_utils/aliases

@@ -1 +1,3 @@
 shippable/posix/group3
+needs/root
+needs/target/setup_nobody

test/integration/targets/module_utils/library/test_cwd_missing.py

@@ -0,0 +1,33 @@
+#!/usr/bin/python
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+import os
+
+from ansible.module_utils.basic import AnsibleModule
+
+
+def main():
+    # This module verifies that AnsibleModule works when cwd does not exist.
+    # This situation can occur as a race condition when the following conditions are met:
+    #
+    # 1) Execute a module which has high startup overhead prior to instantiating AnsibleModule (0.5s is enough in many cases).
+    # 2) Run the module async as the last task in a playbook using connection=local (a fire-and-forget task).
+    # 3) Remove the directory containing the playbook immediately after playbook execution ends (playbook in a temp dir).
+    #
+    # To ease testing of this race condition the deletion of cwd is handled in this module.
+    # This avoids race conditions in the test, including timing cwd deletion between AnsiballZ wrapper execution and AnsibleModule instantiation.
+    # The timing issue with AnsiballZ is due to cwd checking in the wrapper when code coverage is enabled.
+
+    temp = os.path.abspath('temp')
+
+    os.mkdir(temp)
+    os.chdir(temp)
+    os.rmdir(temp)
+
+    module = AnsibleModule(argument_spec=dict())
+    module.exit_json(before=temp, after=os.getcwd())
+
+
+if __name__ == '__main__':
+    main()

test/integration/targets/module_utils/library/test_cwd_unreadable.py

@@ -0,0 +1,28 @@
+#!/usr/bin/python
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+import os
+
+from ansible.module_utils.basic import AnsibleModule
+
+
+def main():
+    # This module verifies that AnsibleModule works when cwd exists but is unreadable.
+    # This situation can occur when running tasks as an unprivileged user.
+
+    try:
+        cwd = os.getcwd()
+    except OSError:
+        # Compensate for macOS being unable to access cwd as an unprivileged user.
+        # This test is a no-op in this case.
+        # Testing for os.getcwd() failures is handled by the test_cwd_missing module.
+        cwd = '/'
+        os.chdir(cwd)
+
+    module = AnsibleModule(argument_spec=dict())
+    module.exit_json(before=cwd, after=os.getcwd())
+
+
+if __name__ == '__main__':
+    main()

test/integration/targets/module_utils/module_utils_basic_setcwd.yml

@@ -0,0 +1,22 @@
+- hosts: testhost
+  gather_facts: no
+  tasks:
+    - name: make sure the nobody user is available
+      include_role:
+        name: setup_nobody
+
+    - name: verify AnsibleModule works when cwd is missing
+      test_cwd_missing:
+      register: missing
+
+    - name: verify AnsibleModule works when cwd is unreadable
+      test_cwd_unreadable:
+      register: unreadable
+      become: yes
+      become_user: nobody  # root can read cwd regardless of permissions, so a non-root user is required here
+
+    - name: verify AnsibleModule was able to adjust cwd as expected
+      assert:
+        that:
+          - missing.before != missing.after
+          - unreadable.before != unreadable.after or unreadable.before == '/'  # allow / fallback on macOS when using an unprivileged user

test/integration/targets/module_utils/runme.sh

@@ -2,5 +2,7 @@
 
 set -eux
 
+ANSIBLE_ROLES_PATH=../ ansible-playbook module_utils_basic_setcwd.yml -i ../../inventory "$@"
+
 ansible-playbook module_utils_test.yml -i ../../inventory -v "$@"
 ANSIBLE_MODULE_UTILS=other_mu_dir ansible-playbook module_utils_envvar.yml -i ../../inventory -v "$@"