[CORD-2080] Adding 'tosca_key' support in xproto

Change-Id: I2c27e4a43140ddecb38f09a33494e5b3ab694059
(cherry picked from commit c3c0f0af175f08a58f5e48956ff56a4779c2c8de)
diff --git a/lib/xos-genx/tests/tosca_test.py b/lib/xos-genx/tests/tosca_test.py
new file mode 100644
index 0000000..48a4db9
--- /dev/null
+++ b/lib/xos-genx/tests/tosca_test.py
@@ -0,0 +1,91 @@
+# Copyright 2017-present Open Networking Foundation
+#
+# 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 unittest
+from xosgenx.generator import XOSGenerator
+from helpers import FakeArgs, XProtoTestHelpers
+
+
+class XProtoToscaTest(unittest.TestCase):
+
+    def setUp(self):
+        self.target = XProtoTestHelpers.write_tmp_target(
+"""
+{%- for m in proto.messages %}
+    {{ xproto_fields_to_tosca_keys(m.fields) }}
+{% endfor -%}
+""")
+
+    def test_xproto_fields_to_tosca_keys_default(self):
+        """
+        [XOS-GenX] if no "tosca_key" is specified, and a name attribute is present in the model, use that
+        """
+        xproto = \
+"""
+option app_label = "test";
+
+message Foo {
+    required string name = 1 [ null = "False", blank="False"];
+}
+"""
+
+        args = FakeArgs()
+        args.inputs = xproto
+        args.target = self.target
+        output = XOSGenerator.generate(args)
+        self.assertIn('name', output)
+
+    def test_xproto_fields_to_tosca_keys_custom(self):
+        """
+        [XOS-GenX] if "tosca_key" is specified, use it
+        """
+        xproto = \
+            """
+            option app_label = "test";
+        
+            message Foo {
+                required string name = 1 [ null = "False", blank="False"];
+                required string key_1 = 2 [ null = "False", blank="False", tosca_key=True];
+                required string key_2 = 3 [ null = "False", blank="False", tosca_key=True];
+            }
+            """
+
+        args = FakeArgs()
+        args.inputs = xproto
+        args.target = self.target
+        output = XOSGenerator.generate(args)
+        self.assertNotIn('name', output)
+        self.assertIn('key_1', output)
+        self.assertIn('key_2', output)
+
+    def test_xproto_fields_link_to_tosca_keys_custom(self):
+        """
+        [XOS-GenX] if "tosca_key" is specified, use it
+        """
+        xproto = \
+            """
+            option app_label = "test";
+
+            message Foo {
+                required string name = 1 [ null = "False", blank="False"];
+                required manytoone provider_service_instance->ServiceInstance:provided_links = 1 [db_index = True, null = False, blank = False, tosca_key=True];
+            }
+            """
+
+        args = FakeArgs()
+        args.inputs = xproto
+        args.target = self.target
+        output = XOSGenerator.generate(args)
+        self.assertNotIn('name', output)
+        self.assertIn('provider_service_instance_id', output)
\ No newline at end of file