Add a funcutils file for working with functions.

Multiple projects are starting to copy around the various
function utilities that exist in nova and elsewhere. It
would seem appropriate that there exist a helper file in
oslo that was used instead as a central place for this type
of code.

Change-Id: Ia83f26da16b0c868506ecf90e1aaf8affecf3617

1 files changed, 139 insertions, 0 deletions

diff --git a/tests/unit/test_funcutils.py b/tests/unit/test_funcutils.py
new file mode 100644
index 0000000..439d825
--- /dev/null
+++ b/tests/unit/test_funcutils.py
@@ -0,0 +1,139 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2011 OpenStack Foundation.
+# Copyright 2011 Justin Santa Barbara
+#
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import functools
+
+from openstack.common import funcutils
+
+from tests import utils
+
+
+class FuncutilsTestCase(utils.BaseTestCase):
+    def _test_func(self, instance, red=None, blue=None):
+        pass
+
+    def test_all_kwargs(self):
+        args = ()
+        kwargs = {'instance': {'uuid': 1}, 'red': 3, 'blue': 4}
+        callargs = funcutils.getcallargs(self._test_func, *args, **kwargs)
+
+        #implicit self counts as an arg
+        self.assertEqual(4, len(callargs))
+        self.assertTrue('instance' in callargs)
+        self.assertEqual({'uuid': 1}, callargs['instance'])
+        self.assertTrue('red' in callargs)
+        self.assertEqual(3, callargs['red'])
+        self.assertTrue('blue' in callargs)
+        self.assertEqual(4, callargs['blue'])
+
+    def test_all_args(self):
+        args = ({'uuid': 1}, 3, 4)
+        kwargs = {}
+        callargs = funcutils.getcallargs(self._test_func, *args, **kwargs)
+
+        #implicit self counts as an arg
+        self.assertEqual(4, len(callargs))
+        self.assertTrue('instance' in callargs)
+        self.assertEqual({'uuid': 1}, callargs['instance'])
+        self.assertTrue('red' in callargs)
+        self.assertEqual(3, callargs['red'])
+        self.assertTrue('blue' in callargs)
+        self.assertEqual(4, callargs['blue'])
+
+    def test_mixed_args(self):
+        args = ({'uuid': 1}, 3)
+        kwargs = {'blue': 4}
+        callargs = funcutils.getcallargs(self._test_func, *args, **kwargs)
+
+        #implicit self counts as an arg
+        self.assertEqual(4, len(callargs))
+        self.assertTrue('instance' in callargs)
+        self.assertEqual({'uuid': 1}, callargs['instance'])
+        self.assertTrue('red' in callargs)
+        self.assertEqual(3, callargs['red'])
+        self.assertTrue('blue' in callargs)
+        self.assertEqual(4, callargs['blue'])
+
+    def test_partial_kwargs(self):
+        args = ()
+        kwargs = {'instance': {'uuid': 1}, 'red': 3}
+        callargs = funcutils.getcallargs(self._test_func, *args, **kwargs)
+
+        #implicit self counts as an arg
+        self.assertEqual(4, len(callargs))
+        self.assertTrue('instance' in callargs)
+        self.assertEqual({'uuid': 1}, callargs['instance'])
+        self.assertTrue('red' in callargs)
+        self.assertEqual(3, callargs['red'])
+        self.assertTrue('blue' in callargs)
+        self.assertEqual(None, callargs['blue'])
+
+    def test_partial_args(self):
+        args = ({'uuid': 1}, 3)
+        kwargs = {}
+        callargs = funcutils.getcallargs(self._test_func, *args, **kwargs)
+
+        #implicit self counts as an arg
+        self.assertEqual(4, len(callargs))
+        self.assertTrue('instance' in callargs)
+        self.assertEqual({'uuid': 1}, callargs['instance'])
+        self.assertTrue('red' in callargs)
+        self.assertEqual(3, callargs['red'])
+        self.assertTrue('blue' in callargs)
+        self.assertEqual(None, callargs['blue'])
+
+    def test_partial_mixed_args(self):
+        args = (3,)
+        kwargs = {'instance': {'uuid': 1}}
+        callargs = funcutils.getcallargs(self._test_func, *args, **kwargs)
+
+        self.assertEqual(4, len(callargs))
+        self.assertTrue('instance' in callargs)
+        self.assertEqual({'uuid': 1}, callargs['instance'])
+        self.assertTrue('red' in callargs)
+        self.assertEqual(3, callargs['red'])
+        self.assertTrue('blue' in callargs)
+        self.assertEqual(None, callargs['blue'])
+
+    def _wrapper(self, function):
+
+        @functools.wraps(function)
+        def decorated_function(self, *args, **kwargs):
+            function(self, *args, **kwargs)
+
+        return decorated_function
+
+    def test_wrapped_X(self):
+
+        def wrapped(self, instance, red=None, blue=None):
+            pass
+
+        old_wrapped = wrapped
+
+        # Wrap it many times and ensure that its still the right one.
+        for _i in range(0, 10):
+            wrapped = self._wrapper(wrapped)
+            func = funcutils.get_wrapped_function(wrapped)
+            func_code = func.func_code
+            self.assertEqual(4, len(func_code.co_varnames))
+            self.assertTrue('self' in func_code.co_varnames)
+            self.assertTrue('instance' in func_code.co_varnames)
+            self.assertTrue('red' in func_code.co_varnames)
+            self.assertTrue('blue' in func_code.co_varnames)
+            self.assertEqual(old_wrapped, func)