add _load_params debug overrides for module args/file passed on cmdline

Updated python module wrapper explode method to drop 'args' file next to module.
Both execute() and excommunicate() debug methods now pass the module args via file to enable debuggers that are picky about stdin.
Updated unit tests to use a context manager for masking/restoring default streams and argv.

lib/ansible/executor/module_common.py

@@ -142,6 +142,7 @@ def debug(command, zipped_mod, json_params):
 
     # Okay to use __file__ here because we're running from a kept file
     basedir = os.path.abspath(os.path.dirname(__file__))
+    args_path = os.path.join(basedir, 'args')
     if command == 'explode':
         # transform the ZIPDATA into an exploded directory of code and then
         # print the path to the code.  This is an easy way for people to look
@@ -163,6 +164,11 @@ def debug(command, zipped_mod, json_params):
                 f.write(z.read(filename))
                 f.close()
 
+        # write the args file
+        f = open(args_path, 'w')
+        f.write(json_params)
+        f.close()
+
         print('Module expanded into:')
         print('%%s' %% os.path.join(basedir, 'ansible'))
         exitcode = 0
@@ -171,7 +177,29 @@ def debug(command, zipped_mod, json_params):
         # Execute the exploded code instead of executing the module from the
         # embedded ZIPDATA.  This allows people to easily run their modified
         # code on the remote machine to see how changes will affect it.
-        exitcode = invoke_module(os.path.join(basedir, 'ansible_module_%(ansible_module)s.py'), basedir, json_params)
+        # This differs slightly from default Ansible execution of Python modules
+        # as it passes the arguments to the module via a file instead of stdin.
+
+        pythonpath = os.environ.get('PYTHONPATH')
+        if pythonpath:
+            os.environ['PYTHONPATH'] = ':'.join((basedir, pythonpath))
+        else:
+            os.environ['PYTHONPATH'] = basedir
+
+        p = subprocess.Popen(['%(interpreter)s', 'ansible_module_%(ansible_module)s.py', args_path], env=os.environ, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE, stdin=subprocess.PIPE)
+        (stdout, stderr) = p.communicate()
+
+        if not isinstance(stderr, (bytes, unicode)):
+            stderr = stderr.read()
+        if not isinstance(stdout, (bytes, unicode)):
+            stdout = stdout.read()
+        if PY3:
+            sys.stderr.buffer.write(stderr)
+            sys.stdout.buffer.write(stdout)
+        else:
+            sys.stderr.write(stderr)
+            sys.stdout.write(stdout)
+        return p.returncode
 
     elif command == 'excommunicate':
         # This attempts to run the module in-process (by importing a main
@@ -182,8 +210,9 @@ def debug(command, zipped_mod, json_params):
         # when using this that are only artifacts of how we're invoking here,
         # not actual bugs (as they don't affect the real way that we invoke
         # ansible modules)
-        sys.stdin = IOStream(json_params)
-        sys.path.insert(0, basedir)
+
+        # stub the
+        sys.argv = ['%(ansible_module)s', args_path]
         from ansible_module_%(ansible_module)s import main
         main()
         print('WARNING: Module returned to wrapper instead of exiting')

lib/ansible/module_utils/basic.py

@@ -1435,11 +1435,23 @@ class AnsibleModule(object):
 
     def _load_params(self):
         ''' read the input and set the params attribute.  Sets the constants as well.'''
+        # debug overrides to read args from file or cmdline
+
         # Avoid tracebacks when locale is non-utf8
-        if sys.version_info < (3,):
-            buffer = sys.stdin.read()
+        if len(sys.argv) > 1:
+            if os.path.isfile(sys.argv[1]):
+                fd = open(sys.argv[1], 'rb')
+                buffer = fd.read()
+                fd.close()
+            else:
+                buffer = sys.argv[1]
+        # default case, read from stdin
         else:
-            buffer = sys.stdin.buffer.read()
+            if sys.version_info < (3,):
+                buffer = sys.stdin.read()
+            else:
+                buffer = sys.stdin.buffer.read()
+
         try:
             params = json.loads(buffer.decode('utf-8'))
         except ValueError:

test/units/mock/procenv.py

@@ -0,0 +1,57 @@
+# (c) 2016, Matt Davis <mdavis@ansible.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import sys
+
+from contextlib import contextmanager
+from io import BytesIO, StringIO
+from ansible.compat.six import PY3
+from ansible.utils.unicode import to_bytes
+
+@contextmanager
+def swap_stdin_and_argv(stdin_data='', argv_data=tuple()):
+    """
+    context manager that temporarily masks the test runner's values for stdin and argv
+    """
+    real_stdin = sys.stdin
+
+    if PY3:
+        sys.stdin = StringIO(stdin_data)
+        sys.stdin.buffer = BytesIO(to_bytes(stdin_data))
+    else:
+        sys.stdin = BytesIO(to_bytes(stdin_data))
+
+    real_argv = sys.argv
+    sys.argv = argv_data
+    yield
+    sys.stdin = real_stdin
+    sys.argv = real_argv
+
+@contextmanager
+def swap_stdout():
+    """
+    context manager that temporarily replaces stdout for tests that need to verify output
+    """
+    old_stdout = sys.stdout
+    fake_stream = BytesIO()
+    sys.stdout = fake_stream
+    yield fake_stream
+    sys.stdout = old_stdout

test/units/module_utils/basic/test__log_invocation.py

@@ -22,75 +22,62 @@ __metaclass__ = type
 
 import sys
 import json
-from io import BytesIO, StringIO
 
-from ansible.compat.six import PY3
-from ansible.utils.unicode import to_bytes
+from units.mock.procenv import swap_stdin_and_argv
 
 from ansible.compat.tests import unittest
 from ansible.compat.tests.mock import MagicMock
 
+
 class TestModuleUtilsBasic(unittest.TestCase):
-    def setUp(self):
-        self.real_stdin = sys.stdin
-        args = json.dumps(
+    @unittest.skipIf(sys.version_info[0] >= 3, "Python 3 is not supported on targets (yet)")
+    def test_module_utils_basic__log_invocation(self):
+        with swap_stdin_and_argv(stdin_data=json.dumps(
             dict(
                 ANSIBLE_MODULE_ARGS=dict(
                     foo=False, bar=[1,2,3], bam="bam", baz=u'baz'),
                 ANSIBLE_MODULE_CONSTANTS=dict()
-                )
-            )
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
-    def tearDown(self):
-        sys.stdin = self.real_stdin
+                ))):
+            from ansible.module_utils import basic
 
-    @unittest.skipIf(sys.version_info[0] >= 3, "Python 3 is not supported on targets (yet)")
-    def test_module_utils_basic__log_invocation(self):
-        from ansible.module_utils import basic
-
-        # test basic log invocation
-        am = basic.AnsibleModule(
-            argument_spec=dict(
-                foo = dict(default=True, type='bool'),
-                bar = dict(default=[], type='list'),
-                bam = dict(default="bam"),
-                baz = dict(default=u"baz"),
-                password = dict(default=True),
-                no_log = dict(default="you shouldn't see me", no_log=True),
-            ),
-        )
+            # test basic log invocation
+            am = basic.AnsibleModule(
+                argument_spec=dict(
+                    foo = dict(default=True, type='bool'),
+                    bar = dict(default=[], type='list'),
+                    bam = dict(default="bam"),
+                    baz = dict(default=u"baz"),
+                    password = dict(default=True),
+                    no_log = dict(default="you shouldn't see me", no_log=True),
+                ),
+            )
 
-        am.log = MagicMock()
-        am._log_invocation()
+            am.log = MagicMock()
+            am._log_invocation()
 
-        # Message is generated from a dict so it will be in an unknown order.
-        # have to check this manually rather than with assert_called_with()
-        args = am.log.call_args[0]
-        self.assertEqual(len(args), 1)
-        message = args[0]
+            # Message is generated from a dict so it will be in an unknown order.
+            # have to check this manually rather than with assert_called_with()
+            args = am.log.call_args[0]
+            self.assertEqual(len(args), 1)
+            message = args[0]
 
-        self.assertEqual(len(message), len('Invoked with bam=bam bar=[1, 2, 3] foo=False baz=baz no_log=NOT_LOGGING_PARAMETER password=NOT_LOGGING_PASSWORD'))
-        self.assertTrue(message.startswith('Invoked with '))
-        self.assertIn(' bam=bam', message)
-        self.assertIn(' bar=[1, 2, 3]', message)
-        self.assertIn(' foo=False', message)
-        self.assertIn(' baz=baz', message)
-        self.assertIn(' no_log=NOT_LOGGING_PARAMETER', message)
-        self.assertIn(' password=NOT_LOGGING_PASSWORD', message)
+            self.assertEqual(len(message), len('Invoked with bam=bam bar=[1, 2, 3] foo=False baz=baz no_log=NOT_LOGGING_PARAMETER password=NOT_LOGGING_PASSWORD'))
+            self.assertTrue(message.startswith('Invoked with '))
+            self.assertIn(' bam=bam', message)
+            self.assertIn(' bar=[1, 2, 3]', message)
+            self.assertIn(' foo=False', message)
+            self.assertIn(' baz=baz', message)
+            self.assertIn(' no_log=NOT_LOGGING_PARAMETER', message)
+            self.assertIn(' password=NOT_LOGGING_PASSWORD', message)
 
-        kwargs = am.log.call_args[1]
-        self.assertEqual(kwargs, 
-                dict(log_args={
-                    'foo': 'False',
-                    'bar': '[1, 2, 3]',
-                    'bam': 'bam',
-                    'baz': 'baz',
-                    'password': 'NOT_LOGGING_PASSWORD',
-                    'no_log': 'NOT_LOGGING_PARAMETER',
-                })
-            )
+            kwargs = am.log.call_args[1]
+            self.assertEqual(kwargs,
+                    dict(log_args={
+                        'foo': 'False',
+                        'bar': '[1, 2, 3]',
+                        'bam': 'bam',
+                        'baz': 'baz',
+                        'password': 'NOT_LOGGING_PASSWORD',
+                        'no_log': 'NOT_LOGGING_PARAMETER',
+                    })
+                )

test/units/module_utils/basic/test_exit_json.py

@@ -23,39 +23,34 @@ __metaclass__ = type
 import copy
 import json
 import sys
-from io import BytesIO, StringIO
 
-from ansible.compat.six import PY3
-from ansible.utils.unicode import to_bytes
 from ansible.compat.tests import unittest
+from units.mock.procenv import swap_stdin_and_argv, swap_stdout
 
 from ansible.module_utils import basic
 from ansible.module_utils.basic import heuristic_log_sanitize
 from ansible.module_utils.basic import return_values, remove_values
 
+
 empty_invocation = {u'module_args': {}}
 
 @unittest.skipIf(sys.version_info[0] >= 3, "Python 3 is not supported on targets (yet)")
 class TestAnsibleModuleExitJson(unittest.TestCase):
-
     def setUp(self):
-        self.old_stdin = sys.stdin
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
+        self.stdin_swap_ctx = swap_stdin_and_argv(stdin_data=args)
+        self.stdin_swap_ctx.__enter__()
 
-        self.old_stdout = sys.stdout
-        self.fake_stream = BytesIO()
-        sys.stdout = self.fake_stream
+        # since we can't use context managers and "with" without overriding run(), call them directly
+        self.stdout_swap_ctx = swap_stdout()
+        self.fake_stream = self.stdout_swap_ctx.__enter__()
 
         self.module = basic.AnsibleModule(argument_spec=dict())
 
     def tearDown(self):
-        sys.stdout = self.old_stdout
-        sys.stdin = self.old_stdin
+        # since we can't use context managers and "with" without overriding run(), call them directly to clean up
+        self.stdin_swap_ctx.__exit__(None, None, None)
+        self.stdout_swap_ctx.__exit__(None, None, None)
 
     def test_exit_json_no_args_exits(self):
         with self.assertRaises(SystemExit) as ctx:
@@ -123,42 +118,24 @@ class TestAnsibleModuleExitValuesRemoved(unittest.TestCase):
                 ),
             )
 
-    def setUp(self):
-        self.old_stdin = sys.stdin
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
-        self.old_stdout = sys.stdout
-
-    def tearDown(self):
-        sys.stdin = self.old_stdin
-        sys.stdout = self.old_stdout
-
     def test_exit_json_removes_values(self):
         self.maxDiff = None
         for args, return_val, expected in self.dataset:
-            sys.stdout = BytesIO()
             params = dict(ANSIBLE_MODULE_ARGS=args, ANSIBLE_MODULE_CONSTANTS={})
             params = json.dumps(params)
-            if PY3:
-                sys.stdin = StringIO(params)
-                sys.stdin.buffer = BytesIO(to_bytes(params))
-            else:
-                sys.stdin = BytesIO(to_bytes(params))
-            module = basic.AnsibleModule(
-                argument_spec = dict(
-                    username=dict(),
-                    password=dict(no_log=True),
-                    token=dict(no_log=True),
-                    ),
-                )
-            with self.assertRaises(SystemExit) as ctx:
-                self.assertEquals(module.exit_json(**return_val), expected)
-            self.assertEquals(json.loads(sys.stdout.getvalue()), expected)
+
+            with swap_stdin_and_argv(stdin_data=params):
+                with swap_stdout():
+                    module = basic.AnsibleModule(
+                        argument_spec = dict(
+                            username=dict(),
+                            password=dict(no_log=True),
+                            token=dict(no_log=True),
+                            ),
+                        )
+                    with self.assertRaises(SystemExit) as ctx:
+                        self.assertEquals(module.exit_json(**return_val), expected)
+                    self.assertEquals(json.loads(sys.stdout.getvalue()), expected)
 
     def test_fail_json_removes_values(self):
         self.maxDiff = None
@@ -166,21 +143,17 @@ class TestAnsibleModuleExitValuesRemoved(unittest.TestCase):
             expected = copy.deepcopy(expected)
             del expected['changed']
             expected['failed'] = True
-            sys.stdout = BytesIO()
             params = dict(ANSIBLE_MODULE_ARGS=args, ANSIBLE_MODULE_CONSTANTS={})
             params = json.dumps(params)
-            if PY3:
-                sys.stdin = StringIO(params)
-                sys.stdin.buffer = BytesIO(to_bytes(params))
-            else:
-                sys.stdin = BytesIO(to_bytes(params))
-            module = basic.AnsibleModule(
-                argument_spec = dict(
-                    username=dict(),
-                    password=dict(no_log=True),
-                    token=dict(no_log=True),
-                    ),
-                )
-            with self.assertRaises(SystemExit) as ctx:
-                self.assertEquals(module.fail_json(**return_val), expected)
-            self.assertEquals(json.loads(sys.stdout.getvalue()), expected)
+            with swap_stdin_and_argv(stdin_data=params):
+                with swap_stdout():
+                    module = basic.AnsibleModule(
+                        argument_spec = dict(
+                            username=dict(),
+                            password=dict(no_log=True),
+                            token=dict(no_log=True),
+                            ),
+                        )
+                    with self.assertRaises(SystemExit) as ctx:
+                        self.assertEquals(module.fail_json(**return_val), expected)
+                    self.assertEquals(json.loads(sys.stdout.getvalue()), expected)

test/units/module_utils/basic/test_log.py

@@ -23,16 +23,14 @@ __metaclass__ = type
 import sys
 import json
 import syslog
-from io import BytesIO, StringIO
-
-from ansible.compat.six import PY3
-from ansible.utils.unicode import to_bytes
 
 from ansible.compat.tests import unittest
 from ansible.compat.tests.mock import patch, MagicMock
+from units.mock.procenv import swap_stdin_and_argv
 
 from ansible.module_utils import basic
 
+
 try:
     # Python 3.4+
     from importlib import reload
@@ -44,15 +42,12 @@ except ImportError:
 
 
 class TestAnsibleModuleSysLogSmokeTest(unittest.TestCase):
-
     def setUp(self):
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        self.real_stdin = sys.stdin
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
+
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap = swap_stdin_and_argv(stdin_data=args)
+        self.stdin_swap.__enter__()
 
         self.am = basic.AnsibleModule(
             argument_spec = dict(),
@@ -64,7 +59,8 @@ class TestAnsibleModuleSysLogSmokeTest(unittest.TestCase):
             basic.has_journal = False
 
     def tearDown(self):
-        sys.stdin = self.real_stdin
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap.__exit__(None, None, None)
         basic.has_journal = self.has_journal
 
     def test_smoketest_syslog(self):
@@ -84,20 +80,18 @@ class TestAnsibleModuleJournaldSmokeTest(unittest.TestCase):
 
     def setUp(self):
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        self.real_stdin = sys.stdin
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
 
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap = swap_stdin_and_argv(stdin_data=args)
+        self.stdin_swap.__enter__()
 
         self.am = basic.AnsibleModule(
             argument_spec = dict(),
         )
 
     def tearDown(self):
-        sys.stdin = self.real_stdin
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap.__exit__(None, None, None)
 
     @unittest.skipUnless(basic.has_journal, 'python systemd bindings not installed')
     def test_smoketest_journal(self):
@@ -134,26 +128,26 @@ class TestAnsibleModuleLogSyslog(unittest.TestCase):
 
     def setUp(self):
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        self.real_stdin = sys.stdin
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap = swap_stdin_and_argv(stdin_data=args)
+        self.stdin_swap.__enter__()
 
         self.am = basic.AnsibleModule(
             argument_spec = dict(),
         )
+
         self.has_journal = basic.has_journal
         if self.has_journal:
             # Systems with journal can still test syslog
             basic.has_journal = False
 
     def tearDown(self):
-        sys.stdin = self.real_stdin
+        # teardown/reset
         basic.has_journal = self.has_journal
 
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap.__exit__(None, None, None)
+
     @patch('syslog.syslog', autospec=True)
     def test_no_log(self, mock_func):
         no_log = self.am.no_log
@@ -191,21 +185,22 @@ class TestAnsibleModuleLogJournal(unittest.TestCase):
             b'non-utf8 :\xff: test': b'non-utf8 :\xff: test'.decode('utf-8', 'replace')
             }
 
+    # overriding run lets us use context managers for setup/teardown-esque behavior
     def setUp(self):
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        self.real_stdin = sys.stdin
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap = swap_stdin_and_argv(stdin_data=args)
+        self.stdin_swap.__enter__()
 
         self.am = basic.AnsibleModule(
             argument_spec = dict(),
         )
 
         self.has_journal = basic.has_journal
-        basic.has_journal = True
+        if self.has_journal:
+            # Systems with journal can still test syslog
+            basic.has_journal = False
+
         self.module_patcher = None
 
         # In case systemd-python is not installed
@@ -218,9 +213,12 @@ class TestAnsibleModuleLogJournal(unittest.TestCase):
                 self._fake_out_reload(basic)
 
     def tearDown(self):
-        sys.stdin = self.real_stdin
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap.__exit__(None, None, None)
 
+        # teardown/reset
         basic.has_journal = self.has_journal
+
         if self.module_patcher:
             self.module_patcher.stop()
             reload(basic)

test/units/module_utils/basic/test_run_command.py

@@ -25,12 +25,11 @@ import sys
 import time
 from io import BytesIO, StringIO
 
-from ansible.compat.six import PY3
-from ansible.utils.unicode import to_bytes
-
 from ansible.compat.tests import unittest
 from ansible.compat.tests.mock import call, MagicMock, Mock, patch, sentinel
 
+from units.mock.procenv import swap_stdin_and_argv
+
 from ansible.module_utils import basic
 from ansible.module_utils.basic import AnsibleModule
 
@@ -46,9 +45,7 @@ class OpenBytesIO(BytesIO):
 
 @unittest.skipIf(sys.version_info[0] >= 3, "Python 3 is not supported on targets (yet)")
 class TestAnsibleModuleRunCommand(unittest.TestCase):
-
     def setUp(self):
-
         self.cmd_out = {
             # os.read() is returning 'bytes', not strings
             sentinel.stdout: BytesIO(),
@@ -66,11 +63,10 @@ class TestAnsibleModuleRunCommand(unittest.TestCase):
                 raise OSError(errno.EPERM, "Permission denied: '/inaccessible'")
 
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap = swap_stdin_and_argv(stdin_data=args)
+        self.stdin_swap.__enter__()
+
         self.module = AnsibleModule(argument_spec=dict())
         self.module.fail_json = MagicMock(side_effect=SystemExit)
 
@@ -96,6 +92,11 @@ class TestAnsibleModuleRunCommand(unittest.TestCase):
 
         self.addCleanup(patch.stopall)
 
+
+    def tearDown(self):
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap.__exit__(None, None, None)
+
     def test_list_as_args(self):
         self.module.run_command(['/bin/ls', 'a', ' b', 'c '])
         self.assertTrue(self.subprocess.Popen.called)

test/units/module_utils/basic/test_safe_eval.py

@@ -22,60 +22,48 @@ __metaclass__ = type
 
 import sys
 import json
-from io import BytesIO, StringIO
 
 from ansible.compat.tests import unittest
-from ansible.compat.six import PY3
-from ansible.utils.unicode import to_bytes
+from units.mock.procenv import swap_stdin_and_argv
 
 class TestAnsibleModuleExitJson(unittest.TestCase):
 
-    def setUp(self):
-        self.real_stdin = sys.stdin
-
-    def tearDown(self):
-        sys.stdin = self.real_stdin
-
     def test_module_utils_basic_safe_eval(self):
         from ansible.module_utils import basic
 
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
 
-        am = basic.AnsibleModule(
-            argument_spec=dict(),
-        )
+        with swap_stdin_and_argv(stdin_data=args):
+            am = basic.AnsibleModule(
+                argument_spec=dict(),
+            )
 
-        # test some basic usage
-        # string (and with exceptions included), integer, bool
-        self.assertEqual(am.safe_eval("'a'"), 'a')
-        self.assertEqual(am.safe_eval("'a'", include_exceptions=True), ('a', None))
-        self.assertEqual(am.safe_eval("1"), 1)
-        self.assertEqual(am.safe_eval("True"), True)
-        self.assertEqual(am.safe_eval("False"), False)
-        self.assertEqual(am.safe_eval("{}"), {})
-        # not passing in a string to convert
-        self.assertEqual(am.safe_eval({'a':1}), {'a':1})
-        self.assertEqual(am.safe_eval({'a':1}, include_exceptions=True), ({'a':1}, None))
-        # invalid literal eval
-        self.assertEqual(am.safe_eval("a=1"), "a=1")
-        res = am.safe_eval("a=1", include_exceptions=True)
-        self.assertEqual(res[0], "a=1")
-        self.assertEqual(type(res[1]), SyntaxError)
-        self.assertEqual(am.safe_eval("a.foo()"), "a.foo()")
-        res = am.safe_eval("a.foo()", include_exceptions=True)
-        self.assertEqual(res[0], "a.foo()")
-        self.assertEqual(res[1], None)
-        self.assertEqual(am.safe_eval("import foo"), "import foo")
-        res = am.safe_eval("import foo", include_exceptions=True)
-        self.assertEqual(res[0], "import foo")
-        self.assertEqual(res[1], None)
-        self.assertEqual(am.safe_eval("__import__('foo')"), "__import__('foo')")
-        res = am.safe_eval("__import__('foo')", include_exceptions=True)
-        self.assertEqual(res[0], "__import__('foo')")
-        self.assertEqual(type(res[1]), ValueError)
+            # test some basic usage
+            # string (and with exceptions included), integer, bool
+            self.assertEqual(am.safe_eval("'a'"), 'a')
+            self.assertEqual(am.safe_eval("'a'", include_exceptions=True), ('a', None))
+            self.assertEqual(am.safe_eval("1"), 1)
+            self.assertEqual(am.safe_eval("True"), True)
+            self.assertEqual(am.safe_eval("False"), False)
+            self.assertEqual(am.safe_eval("{}"), {})
+            # not passing in a string to convert
+            self.assertEqual(am.safe_eval({'a':1}), {'a':1})
+            self.assertEqual(am.safe_eval({'a':1}, include_exceptions=True), ({'a':1}, None))
+            # invalid literal eval
+            self.assertEqual(am.safe_eval("a=1"), "a=1")
+            res = am.safe_eval("a=1", include_exceptions=True)
+            self.assertEqual(res[0], "a=1")
+            self.assertEqual(type(res[1]), SyntaxError)
+            self.assertEqual(am.safe_eval("a.foo()"), "a.foo()")
+            res = am.safe_eval("a.foo()", include_exceptions=True)
+            self.assertEqual(res[0], "a.foo()")
+            self.assertEqual(res[1], None)
+            self.assertEqual(am.safe_eval("import foo"), "import foo")
+            res = am.safe_eval("import foo", include_exceptions=True)
+            self.assertEqual(res[0], "import foo")
+            self.assertEqual(res[1], None)
+            self.assertEqual(am.safe_eval("__import__('foo')"), "__import__('foo')")
+            res = am.safe_eval("__import__('foo')", include_exceptions=True)
+            self.assertEqual(res[0], "__import__('foo')")
+            self.assertEqual(type(res[1]), ValueError)
 

test/units/module_utils/test_basic.py

@@ -31,8 +31,7 @@ try:
 except ImportError:
     import __builtin__ as builtins
 
-from ansible.compat.six import PY3
-from ansible.utils.unicode import to_bytes
+from units.mock.procenv import swap_stdin_and_argv
 
 from ansible.compat.tests import unittest
 from ansible.compat.tests.mock import patch, MagicMock, mock_open, Mock, call
@@ -40,12 +39,16 @@ from ansible.compat.tests.mock import patch, MagicMock, mock_open, Mock, call
 realimport = builtins.__import__
 
 class TestModuleUtilsBasic(unittest.TestCase):
- 
+
     def setUp(self):
-        self.real_stdin = sys.stdin
+        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap = swap_stdin_and_argv(stdin_data=args)
+        self.stdin_swap.__enter__()
 
     def tearDown(self):
-        sys.stdin = self.real_stdin
+        # unittest doesn't have a clean place to use a context manager, so we have to enter/exit manually
+        self.stdin_swap.__exit__(None, None, None)
 
     def clear_modules(self, mods):
         for mod in mods:
@@ -271,13 +274,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_creation(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec=dict(),
         )
@@ -293,94 +289,71 @@ class TestModuleUtilsBasic(unittest.TestCase):
 
         # should test ok
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={"foo": "hello"}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
 
-        am = basic.AnsibleModule(
-            argument_spec = arg_spec,
-            mutually_exclusive = mut_ex,
-            required_together = req_to,
-            no_log=True, 
-            check_invalid_arguments=False, 
-            add_file_common_args=True, 
-            supports_check_mode=True,
-        )
+        with swap_stdin_and_argv(stdin_data=args):
+            am = basic.AnsibleModule(
+                argument_spec = arg_spec,
+                mutually_exclusive = mut_ex,
+                required_together = req_to,
+                no_log=True,
+                check_invalid_arguments=False,
+                add_file_common_args=True,
+                supports_check_mode=True,
+            )
 
         # FIXME: add asserts here to verify the basic config
 
         # fail, because a required param was not specified
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
-        self.assertRaises(
-            SystemExit,
-            basic.AnsibleModule,
-            argument_spec = arg_spec,
-            mutually_exclusive = mut_ex,
-            required_together = req_to,
-            no_log=True,
-            check_invalid_arguments=False,
-            add_file_common_args=True,
-            supports_check_mode=True,
-        )
+
+        with swap_stdin_and_argv(stdin_data=args):
+            self.assertRaises(
+                SystemExit,
+                basic.AnsibleModule,
+                argument_spec = arg_spec,
+                mutually_exclusive = mut_ex,
+                required_together = req_to,
+                no_log=True,
+                check_invalid_arguments=False,
+                add_file_common_args=True,
+                supports_check_mode=True,
+            )
 
         # fail because of mutually exclusive parameters
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={"foo":"hello", "bar": "bad", "bam": "bad"}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
-        self.assertRaises(
-            SystemExit, 
-            basic.AnsibleModule,
-            argument_spec = arg_spec,
-            mutually_exclusive = mut_ex,
-            required_together = req_to,
-            no_log=True, 
-            check_invalid_arguments=False, 
-            add_file_common_args=True, 
-            supports_check_mode=True,
-        )
+
+        with swap_stdin_and_argv(stdin_data=args):
+            self.assertRaises(
+                SystemExit,
+                basic.AnsibleModule,
+                argument_spec = arg_spec,
+                mutually_exclusive = mut_ex,
+                required_together = req_to,
+                no_log=True,
+                check_invalid_arguments=False,
+                add_file_common_args=True,
+                supports_check_mode=True,
+            )
 
         # fail because a param required due to another param was not specified
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={"bam": "bad"}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
-        self.assertRaises(
-            SystemExit,
-            basic.AnsibleModule,
-            argument_spec = arg_spec,
-            mutually_exclusive = mut_ex,
-            required_together = req_to,
-            no_log=True,
-            check_invalid_arguments=False,
-            add_file_common_args=True,
-            supports_check_mode=True,
-        )
+
+        with swap_stdin_and_argv(stdin_data=args):
+            self.assertRaises(
+                SystemExit,
+                basic.AnsibleModule,
+                argument_spec = arg_spec,
+                mutually_exclusive = mut_ex,
+                required_together = req_to,
+                no_log=True,
+                check_invalid_arguments=False,
+                add_file_common_args=True,
+                supports_check_mode=True,
+            )
 
     def test_module_utils_basic_ansible_module_load_file_common_arguments(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -429,13 +402,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_selinux_mls_enabled(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -455,13 +421,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_selinux_initial_context(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -475,13 +434,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_selinux_enabled(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -513,13 +465,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_selinux_default_context(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -555,13 +500,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_selinux_context(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -604,59 +542,49 @@ class TestModuleUtilsBasic(unittest.TestCase):
         from ansible.module_utils import basic
 
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={"SELINUX_SPECIAL_FS": "nfs,nfsd,foos"}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
 
-        am = basic.AnsibleModule(
-            argument_spec = dict(),
-        )
-        print(am.constants)
+        with swap_stdin_and_argv(stdin_data=args):
+
+            am = basic.AnsibleModule(
+                argument_spec = dict(),
+            )
+            print(am.constants)
 
-        def _mock_find_mount_point(path):
-            if path.startswith('/some/path'):
-                return '/some/path'
-            elif path.startswith('/weird/random/fstype'):
-                return '/weird/random/fstype'
-            return '/'
+            def _mock_find_mount_point(path):
+                if path.startswith('/some/path'):
+                    return '/some/path'
+                elif path.startswith('/weird/random/fstype'):
+                    return '/weird/random/fstype'
+                return '/'
 
-        am.find_mount_point = MagicMock(side_effect=_mock_find_mount_point)
-        am.selinux_context = MagicMock(return_value=['foo_u', 'foo_r', 'foo_t', 's0'])
+            am.find_mount_point = MagicMock(side_effect=_mock_find_mount_point)
+            am.selinux_context = MagicMock(return_value=['foo_u', 'foo_r', 'foo_t', 's0'])
 
-        m = mock_open()
-        m.side_effect = OSError
+            m = mock_open()
+            m.side_effect = OSError
 
-        with patch.object(builtins, 'open', m, create=True):
-            self.assertEqual(am.is_special_selinux_path('/some/path/that/should/be/nfs'), (False, None))
+            with patch.object(builtins, 'open', m, create=True):
+                self.assertEqual(am.is_special_selinux_path('/some/path/that/should/be/nfs'), (False, None))
 
-        mount_data = [
-            '/dev/disk1 / ext4 rw,seclabel,relatime,data=ordered 0 0\n',
-            '1.1.1.1:/path/to/nfs /some/path nfs ro 0 0\n',
-            'whatever /weird/random/fstype foos rw 0 0\n',
-        ]
+            mount_data = [
+                '/dev/disk1 / ext4 rw,seclabel,relatime,data=ordered 0 0\n',
+                '1.1.1.1:/path/to/nfs /some/path nfs ro 0 0\n',
+                'whatever /weird/random/fstype foos rw 0 0\n',
+            ]
 
-        # mock_open has a broken readlines() implementation apparently...
-        # this should work by default but doesn't, so we fix it
-        m = mock_open(read_data=''.join(mount_data))
-        m.return_value.readlines.return_value = mount_data
+            # mock_open has a broken readlines() implementation apparently...
+            # this should work by default but doesn't, so we fix it
+            m = mock_open(read_data=''.join(mount_data))
+            m.return_value.readlines.return_value = mount_data
 
-        with patch.object(builtins, 'open', m, create=True):
-            self.assertEqual(am.is_special_selinux_path('/some/random/path'), (False, None))
-            self.assertEqual(am.is_special_selinux_path('/some/path/that/should/be/nfs'), (True, ['foo_u', 'foo_r', 'foo_t', 's0']))
-            self.assertEqual(am.is_special_selinux_path('/weird/random/fstype/path'), (True, ['foo_u', 'foo_r', 'foo_t', 's0']))
+            with patch.object(builtins, 'open', m, create=True):
+                self.assertEqual(am.is_special_selinux_path('/some/random/path'), (False, None))
+                self.assertEqual(am.is_special_selinux_path('/some/path/that/should/be/nfs'), (True, ['foo_u', 'foo_r', 'foo_t', 's0']))
+                self.assertEqual(am.is_special_selinux_path('/weird/random/fstype/path'), (True, ['foo_u', 'foo_r', 'foo_t', 's0']))
 
     def test_module_utils_basic_ansible_module_to_filesystem_str(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -667,13 +595,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_user_and_group(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -688,13 +609,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_find_mount_point(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -718,13 +632,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_set_context_if_different(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -769,13 +676,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_set_owner_if_different(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -814,13 +714,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_set_group_if_different(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -859,13 +752,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
     def test_module_utils_basic_ansible_module_set_mode_if_different(self):
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -953,13 +839,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
 
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )
@@ -1137,13 +1016,6 @@ class TestModuleUtilsBasic(unittest.TestCase):
 
         from ansible.module_utils import basic
 
-        args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-        if PY3:
-            sys.stdin = StringIO(args)
-            sys.stdin.buffer = BytesIO(to_bytes(args))
-        else:
-            sys.stdin = BytesIO(to_bytes(args))
-
         am = basic.AnsibleModule(
             argument_spec = dict(),
         )

test/units/module_utils/test_distribution_version.py

@@ -26,6 +26,8 @@ from io import BytesIO, StringIO
 from ansible.compat.six import PY3
 from ansible.utils.unicode import to_bytes
 
+from units.mock.procenv import swap_stdin_and_argv
+
 # for testing
 from ansible.compat.tests import unittest
 from ansible.compat.tests.mock import patch
@@ -323,26 +325,17 @@ def test_distribution_version():
     # needs to be in here, because the import fails with python3 still
     import ansible.module_utils.facts as facts
 
-    real_stdin = sys.stdin
     from ansible.module_utils import basic
 
     args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}, ANSIBLE_MODULE_CONSTANTS={}))
-    if PY3:
-        sys.stdin = StringIO(args)
-        sys.stdin.buffer = BytesIO(to_bytes(args))
-    else:
-        sys.stdin = BytesIO(to_bytes(args))
-    module = basic.AnsibleModule(argument_spec=dict())
-
-    for t in TESTSETS:
-        # run individual tests via generator
-        # set nicer stdout output for nosetest
-        _test_one_distribution.description = "check distribution_version for %s" % t['name']
-        yield _test_one_distribution, facts, module, t
-
-
-    sys.stdin = real_stdin
+    with swap_stdin_and_argv(stdin_data=args):
+        module = basic.AnsibleModule(argument_spec=dict())
 
+        for t in TESTSETS:
+            # run individual tests via generator
+            # set nicer stdout output for nosetest
+            _test_one_distribution.description = "check distribution_version for %s" % t['name']
+            yield _test_one_distribution, facts, module, t
 
 def _test_one_distribution(facts, module, testcase):
     """run the test on one distribution testcase