Fix InvalidTypeError in get_attribute function

Fix InvalidTypeError is raised when a custom def datatype attribute
is requested in a function.
It only required to add custom defs in the DataType validation.

Closes-Bug: 1964972
Change-Id: Ie3413c6d6ba86d0fd5eb819dfc9770b8211badc6

toscaparser/functions.py

@@ -179,7 +179,8 @@ class GetAttribute(Function):
                                          ).format(GET_ATTRIBUTE, elem)))
                         return
                     else:  # It is a complex type
-                        data_type = DataType(value_type)
+                        data_type = DataType(value_type,
+                                             self.tosca_tpl.custom_defs)
                         props = data_type.get_all_properties()
                         found = [props[elem]] if elem in props else []
                         if found:

toscaparser/tests/data/custom_types/custom_data_type.yaml

@@ -0,0 +1,21 @@
+tosca_definitions_version: tosca_simple_yaml_1_0
+
+data_types:
+
+  tosca.datatypes.SomeType:
+    derived_from: tosca.datatypes.Root
+    properties:
+      tasks:
+        type: map
+        entry_schema:
+          type: string
+
+node_types:
+
+  tosca.nodes.SomeApp:
+    derived_from: tosca.nodes.SoftwareComponent
+    attributes:
+      some_new_att:
+        type: map
+        entry_schema:
+          type: tosca.datatypes.SomeType

toscaparser/tests/data/functions/test_get_attribute_custom_data_type.yaml

@@ -0,0 +1,36 @@
+tosca_definitions_version: tosca_simple_yaml_1_0
+
+description: Template for testing get_attribute with a custom data type
+
+imports:
+  - ../custom_types/custom_data_type.yaml
+
+topology_template:
+
+  node_templates:
+
+    some_app:
+      type: tosca.nodes.SomeApp
+      requirements:
+      - host: server
+
+    server:
+      type: tosca.nodes.Compute
+      capabilities:
+        # Host container properties
+        host:
+          properties:
+            num_cpus: 2
+            disk_size: 10 GB
+            mem_size: 512 MB
+        # Guest Operating System properties
+        os:
+          properties:
+            # host Operating System image properties
+            architecture: x86_64
+            type: Linux
+            distribution: RHEL
+            version: 6.5
+  outputs:
+    url:
+      value: { get_attribute: [ some_app, some_new_att, map_value, tasks, other_map ]}

toscaparser/tests/test_functions.py

@@ -342,6 +342,10 @@ class GetAttributeTest(TestCase):
         self.assertIsNotNone(self._load_template(
             'functions/test_container_cap_child.yaml'))
 
+    def test_get_attribute_custom_data_type(self):
+        self.assertIsNotNone(self._load_template(
+            'functions/test_get_attribute_custom_data_type.yaml'))
+
 
 class ConcatTest(TestCase):