Fix validation for invalid type

Fix validation for invalid type when found along with an imports section
in a TOSCA template.

Change-Id: I6b0c6299c1ef96b037527db68f9f86a5a81dded5
Closes-Bug: #1656994

toscaparser/elements/entity_type.py

@@ -93,7 +93,7 @@ class EntityType(object):
             return False
 
     def entity_value(self, defs, key):
-        if key in defs:
+        if defs and key in defs:
             return defs[key]
 
     def get_value(self, ndtype, defs=None, parent=None):
@@ -102,7 +102,7 @@ class EntityType(object):
             if not hasattr(self, 'defs'):
                 return None
             defs = self.defs
-        if ndtype in defs:
+        if defs and ndtype in defs:
             # copy the value to avoid that next operations add items in the
             # item definitions
             value = copy.copy(defs[ndtype])
@@ -110,7 +110,7 @@ class EntityType(object):
             p = self
             if p:
                 while p:
-                    if ndtype in p.defs:
+                    if p.defs and ndtype in p.defs:
                         # get the parent value
                         parent_value = p.defs[ndtype]
                         if value:

toscaparser/tests/data/test_multiple_validation_errors.yaml

@@ -35,6 +35,9 @@ topology_template:
       default: 3306
 
   node_templates:
+    xyz:
+      type: tosca.nodes.XYZ
+
     wordpress:
       type: tosca.nodes.WebApplication.WordPress
       requirement:

toscaparser/tests/test_toscatpl.py

@@ -580,6 +580,10 @@ class ToscaTemplateTest(TestCase):
         exception.ExceptionCollector.assertExceptionMessage(
             exception.MissingRequiredFieldError, err9_msg)
 
+        err10_msg = _('Type "tosca.nodes.XYZ" is not a valid type.')
+        exception.ExceptionCollector.assertExceptionMessage(
+            exception.InvalidTypeError, err10_msg)
+
     def test_invalid_section_names(self):
         tosca_tpl = os.path.join(
             os.path.dirname(os.path.abspath(__file__)),