Fix @contextmanager leak on exception. (#21031)

* Fix @contextmanager leak on exception.
* Fix test leaks of global module args cache.

test/units/mock/procenv.py

@@ -36,18 +36,22 @@ 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
+    real_argv = sys.argv
 
     if PY3:
-        sys.stdin = StringIO(stdin_data)
-        sys.stdin.buffer = BytesIO(to_bytes(stdin_data))
+        fake_stream = StringIO(stdin_data)
+        fake_stream.buffer = BytesIO(to_bytes(stdin_data))
     else:
-        sys.stdin = BytesIO(to_bytes(stdin_data))
+        fake_stream = BytesIO(to_bytes(stdin_data))
 
-    real_argv = sys.argv
-    sys.argv = argv_data
-    yield
-    sys.stdin = real_stdin
-    sys.argv = real_argv
+    try:
+        sys.stdin = fake_stream
+        sys.argv = argv_data
+
+        yield
+    finally:
+        sys.stdin = real_stdin
+        sys.argv = real_argv
 
 
 @contextmanager
@@ -56,13 +60,18 @@ def swap_stdout():
     context manager that temporarily replaces stdout for tests that need to verify output
     """
     old_stdout = sys.stdout
+
     if PY3:
         fake_stream = StringIO()
     else:
         fake_stream = BytesIO()
-    sys.stdout = fake_stream
-    yield fake_stream
-    sys.stdout = old_stdout
+
+    try:
+        sys.stdout = fake_stream
+
+        yield fake_stream
+    finally:
+        sys.stdout = old_stdout
 
 
 class ModuleTestCase(unittest.TestCase):

test/units/module_utils/basic/test__log_invocation.py

@@ -40,6 +40,7 @@ class TestModuleUtilsBasic(unittest.TestCase):
             from ansible.module_utils import basic
 
             # test basic log invocation
+            basic._ANSIBLE_ARGS = None
             am = basic.AnsibleModule(
                 argument_spec=dict(
                     foo = dict(default=True, type='bool'),

test/units/module_utils/test_basic.py

@@ -311,6 +311,7 @@ class TestModuleUtilsBasic(ModuleTestCase):
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={"foo":"hello", "bar": "bad", "bam": "bad"}))
 
         with swap_stdin_and_argv(stdin_data=args):
+            basic._ANSIBLE_ARGS = None
             self.assertRaises(
                 SystemExit,
                 basic.AnsibleModule,
@@ -327,6 +328,7 @@ class TestModuleUtilsBasic(ModuleTestCase):
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={"bam": "bad"}))
 
         with swap_stdin_and_argv(stdin_data=args):
+            basic._ANSIBLE_ARGS = None
             self.assertRaises(
                 SystemExit,
                 basic.AnsibleModule,
@@ -580,12 +582,11 @@ class TestModuleUtilsBasic(ModuleTestCase):
 
     def test_module_utils_basic_ansible_module_is_special_selinux_path(self):
         from ansible.module_utils import basic
-        basic._ANSIBLE_ARGS = None
 
         args = json.dumps(dict(ANSIBLE_MODULE_ARGS={'_ansible_selinux_special_fs': "nfs,nfsd,foos"}))
 
         with swap_stdin_and_argv(stdin_data=args):
-
+            basic._ANSIBLE_ARGS = None
             am = basic.AnsibleModule(
                 argument_spec = dict(),
             )

test/units/module_utils/test_distribution_version.py

@@ -721,6 +721,7 @@ def test_distribution_version():
 
     args = json.dumps(dict(ANSIBLE_MODULE_ARGS={}))
     with swap_stdin_and_argv(stdin_data=args):
+        basic._ANSIBLE_ARGS = None
         module = basic.AnsibleModule(argument_spec=dict())
 
         for t in TESTSETS: