Fail to parse capabilities without properties

Fixed a bug that can not be parsed if properties are not defined
in the parent resource described in capabilities.
Story: #2006298
Task: #36010

Change-Id: I32e3afbd454ccaa807f7d1b049f027c97a627701

toscaparser/elements/capabilitytype.py

@@ -35,7 +35,8 @@ class CapabilityTypeDef(StatefulEntityType):
         parent_properties = {}
         if self.parent_capabilities:
             for type, value in self.parent_capabilities.items():
-                parent_properties[type] = value.get('properties')
+                if self.PROPERTIES in value:
+                    parent_properties[type] = value.get(self.PROPERTIES)
         if self.properties:
             for prop, schema in self.properties.items():
                 properties.append(PropertyDef(prop, None, schema))

toscaparser/tests/data/test_capability_without_properties.yaml

@@ -0,0 +1,36 @@
+tosca_definitions_version: tosca_simple_yaml_1_0
+
+description: >
+  Test resources for which properties are not defined in
+  the parent of capabilitytype.
+  TestApp has capabilities->test_cap,
+  and the type of test_cap is TestCapabilityAA.
+  The parents of TestCapabilityAA is TestCapabilityA,
+  and TestCapabilityA has no properties.
+
+node_types:
+  tosca.nodes.WebApplication.TestApp:
+    derived_from: tosca.nodes.WebApplication
+    capabilities:
+      test_cap:
+        type: tosca.capabilities.TestCapabilityAA
+
+  # Node whose parent is Root and does not have properties
+  tosca.capabilities.TestCapabilityA:
+    derived_from: tosca.capabilities.Root
+
+  tosca.capabilities.TestCapabilityAA:
+    derived_from: tosca.capabilities.TestCapabilityA
+    properties:
+      test:
+        type: integer
+        required: false
+
+topology_template:
+  node_templates:
+    test_app:
+      type: tosca.nodes.WebApplication.TestApp
+      capabilities:
+        test_cap:
+          properties:
+            test: 1

toscaparser/tests/test_toscatpl.py

@@ -439,6 +439,40 @@ class ToscaTemplateTest(TestCase):
         self.assertEqual('Type "tosca.capabilities.TestCapability" is not '
                          'a valid type.', six.text_type(err))
 
+    def test_capability_without_properties(self):
+        expected_version = "tosca_simple_yaml_1_0"
+        expected_description = \
+            "Test resources for which properties are not defined in "\
+            "the parent of capabilitytype. "\
+            "TestApp has capabilities->test_cap, "\
+            "and the type of test_cap is TestCapabilityAA. "\
+            "The parents of TestCapabilityAA is TestCapabilityA, "\
+            "and TestCapabilityA has no properties."
+        expected_nodetemplates = {
+            "test_app": {
+                "type": "tosca.nodes.WebApplication.TestApp",
+                "capabilities": {
+                    "test_cap": {
+                        "properties": {
+                            "test": 1
+                        }
+                    }
+                }
+            }
+        }
+
+        tosca_tpl = os.path.join(
+            os.path.dirname(os.path.abspath(__file__)),
+            "data/test_capability_without_properties.yaml")
+        tosca = ToscaTemplate(tosca_tpl)
+
+        self.assertEqual(expected_version, tosca.version)
+        self.assertEqual(expected_description, tosca.description)
+        self.assertEqual(
+            expected_nodetemplates,
+            tosca.nodetemplates[0].templates,
+        )
+
     def test_local_template_with_local_relpath_import(self):
         tosca_tpl = os.path.join(
             os.path.dirname(os.path.abspath(__file__)),