Unit test for CLI

This adds unit tests for the shell.py file, which is what we use for the
oslopolicy-checker command.

Change-Id: I52d8669b30e868a4fbdb33316f4db31947b08fa2

oslo_policy/tests/test_shell.py

@@ -0,0 +1,49 @@
+# Copyright (c) 2018 OpenStack Foundation.
+# 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.
+
+from oslo_serialization import jsonutils
+
+from oslo_policy import shell
+from oslo_policy.tests import base
+from oslo_policy.tests import token_fixture
+
+
+class CheckerTestCase(base.PolicyBaseTestCase):
+
+    SAMPLE_POLICY = '''---
+"sample_rule": "role:service"
+"sampleservice:sample_rule": ""
+'''
+
+    def setUp(self):
+        super(CheckerTestCase, self).setUp()
+        self.create_config_file("policy.yaml", self.SAMPLE_POLICY)
+        self.create_config_file(
+            "access.json",
+            jsonutils.dumps(token_fixture.SCOPED_TOKEN_FIXTURE))
+
+    def test_all_nonadmin(self):
+
+        policy_file = open(self.get_config_file_fullname('policy.yaml'), 'r')
+        access_file = open(self.get_config_file_fullname('access.json'), 'r')
+        apply_rule = None
+        is_admin = False
+        stdout = self._capture_stdout()
+
+        shell.tool(policy_file, access_file, apply_rule, is_admin)
+
+        expected = '''passed: sampleservice:sample_rule
+'''
+        self.assertEqual(expected, stdout.getvalue())