Unit tests: share common code (#31456)

* move set_module_args to units.modules.utils
* unit tests: reuse set_module_args
* unit tests: mock exit/fail_json in module.utils.ModuleTestCase
* unit tests: use module.utils.ModuleTestCase
* unit tests: fix 'import shadowed by loop variable'

test/units/modules/system/test_iptables.py

@@ -1,52 +1,21 @@
-import json
-
 from ansible.compat.tests import unittest
 from ansible.compat.tests.mock import patch
 from ansible.module_utils import basic
 from ansible.modules.system import iptables
-from ansible.module_utils._text import to_bytes
-
-
-def set_module_args(args):
-    args = json.dumps({'ANSIBLE_MODULE_ARGS': args})
-    basic._ANSIBLE_ARGS = to_bytes(args)
-
-
-class AnsibleExitJson(Exception):
-    pass
-
-
-class AnsibleFailJson(Exception):
-    pass
-
-
-def exit_json(*args, **kwargs):
-    if 'changed' not in kwargs:
-        kwargs['changed'] = False
-    raise AnsibleExitJson(kwargs)
-
-
-def fail_json(*args, **kwargs):
-    kwargs['failed'] = True
-    raise AnsibleFailJson(kwargs)
+from units.modules.utils import AnsibleExitJson, AnsibleFailJson, ModuleTestCase, set_module_args
 
 
 def get_bin_path(*args, **kwargs):
     return "/sbin/iptables"
 
 
-class TestIptables(unittest.TestCase):
+class TestIptables(ModuleTestCase):
 
     def setUp(self):
-        self.mock_basic = patch.multiple(basic.AnsibleModule,
-                                         exit_json=exit_json,
-                                         fail_json=fail_json,
-                                         get_bin_path=get_bin_path)
-        self.mock_basic.start()
-        self.addCleanup(self.mock_basic.stop)
-
-    def tearDown(self):
-        pass
+        super(TestIptables, self).setUp()
+        self.mock_get_bin_path = patch.object(basic.AnsibleModule, 'get_bin_path', get_bin_path)
+        self.mock_get_bin_path.start()
+        self.addCleanup(self.mock_get_bin_path.stop)  # ensure that the patching is 'undone'
 
     def test_without_required_parameters(self):
         """Failure must occurs when all parameters are missing"""