Test errors are raised when unsupported types are serialized

Author: oliverjwroberts

datahub/documents/serializers.py

@@ -62,13 +62,13 @@ class RelatedObjectRelatedField(serializers.RelatedField):
 
     def to_representation(self, instance):
         """Convert model instance to built-in Python (JSON friendly) data types."""
-        content_type = ContentType.objects.get_for_model(instance)
         if isinstance(instance, (Company)):
             return {
                 'id': str(instance.id),
                 'name': instance.name,
             }
-        return Exception(f'Unexpected type of related object: {content_type.model}')
+        content_type = ContentType.objects.get_for_model(instance)
+        raise Exception(f'Unexpected type of related object: {format_content_type(content_type)}')
 
 
 class GenericDocumentRetrieveSerializer(serializers.ModelSerializer):

datahub/documents/test/test_serializers.py

@@ -1,5 +1,9 @@
 import pytest
 
+from django.contrib.contenttypes.models import ContentType
+
+from datahub.company.test.factories import CompanyFactory
+from datahub.documents.models import GenericDocument
 from datahub.documents.serializers import (
     GenericDocumentRetrieveSerializer,
     SharePointDocumentSerializer,
@@ -12,6 +16,7 @@
     assert_retrieved_generic_document,
     assert_retrieved_sharepoint_document,
 )
+from datahub.investment.project.test.factories import InvestmentProjectFactory
 
 
 pytestmark = pytest.mark.django_db
@@ -33,3 +38,39 @@ def test_serializing_instance_returns_expected_fields(self):
         generic_document = CompanySharePointDocumentFactory()
         serializer = GenericDocumentRetrieveSerializer(generic_document)
         assert_retrieved_generic_document(generic_document, serializer.data)
+
+    def test_serializer_raises_error_if_unsupported_document_type(self):
+        unsupported_document = CompanySharePointDocumentFactory()
+        unsupported_document_type = ContentType.objects.get_for_model(unsupported_document)
+
+        company = CompanyFactory()
+        company_type = ContentType.objects.get_for_model(company)
+
+        generic_document = GenericDocument.objects.create(
+            document_type=unsupported_document_type,
+            document_object_id=unsupported_document.id,
+            related_object_type=company_type,
+            related_object_id=company.id,
+        )
+        with pytest.raises(Exception):
+            serializer = GenericDocumentRetrieveSerializer(generic_document)
+            serializer.data
+
+    def test_serializer_raises_error_if_unsupported_related_object_type(self):
+        document = SharePointDocumentFactory()
+        document_type = ContentType.objects.get_for_model(document)
+
+        unsupported_related_object = InvestmentProjectFactory()
+        unsupported_related_object_type = ContentType.objects.get_for_model(
+            unsupported_related_object,
+        )
+
+        generic_document = GenericDocument.objects.create(
+            document_type=document_type,
+            document_object_id=document.id,
+            related_object_type=unsupported_related_object_type,
+            related_object_id=unsupported_related_object.id,
+        )
+        with pytest.raises(Exception):
+            serializer = GenericDocumentRetrieveSerializer(generic_document)
+            serializer.data