Fix failure when component id is not numeric

Just catch the ValueError and turn it into a proper error message. Tests
are added for this case.

pdc/apps/component/tests.py

@@ -313,6 +313,11 @@ def test_retrieve_global_component_contacts(self):
         self.assertEqual(response.data['contact']['email'],
                          'person1@test.com')
 
+    def test_list_for_non_int_component_id(self):
+        url = reverse('globalcomponentcontact-list', kwargs={'instance_pk': 'hello'})
+        response = self.client.get(url, format='json')
+        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
+
     def test_update_global_component_contact(self):
         url = reverse('globalcomponentcontact-detail', kwargs={'instance_pk': 2,
                                                                'pk': 1})
@@ -488,6 +493,11 @@ def test_list_specified_global_component_labels(self):
         self.assertEqual(response.data.get('results')[0].get('name'), self.args_label1.get('name'))
         self.assertEqual(response.data.get('results')[0].get('description'), self.args_label1.get('description'))
 
+    def test_list_for_non_int_component_id(self):
+        url = reverse('globalcomponentlabel-list', kwargs={'instance_pk': 'hello'})
+        response = self.client.get(url, format='json')
+        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
+
     def test_retrieve_specified_global_component_label(self):
         url = reverse('globalcomponentlabel-detail', kwargs={'instance_pk': 1, 'pk': 1})
         response = self.client.get(url, format='json')
@@ -822,6 +832,11 @@ def test_release_component_contacts_url(self):
         self.assertContains(response, 'release-components', 3)
         self.assertContains(response, 'global-components', 2)
 
+    def test_list_for_non_int_component_id(self):
+        url = reverse('releasecomponentcontact-list', kwargs={'instance_pk': 'hello'})
+        response = self.client.get(url, format='json')
+        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
+
     def test_detail_release_component_not_exist(self):
         url = reverse('releasecomponent-detail', kwargs={'pk': 9999})
         response = self.client.get(url, format='json')
@@ -1302,6 +1317,11 @@ def test_get_single_release_component_contact(self):
         response = self.client.get(url)
         self.assertEqual(response.status_code, status.HTTP_200_OK)
 
+    def test_get_single_release_component_contact_with_bad_component_id(self):
+        url = reverse('releasecomponentcontact-detail', kwargs={'instance_pk': 'hello', 'pk': 5})
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
+
     def test_assign_label_to_global_component_without_name(self):
         url = reverse('globalcomponentlabel-list', kwargs={'instance_pk': 1})
         response = self.client.post(url, format='json', data={})

pdc/apps/component/views.py

@@ -8,6 +8,7 @@
 
 from django.contrib.contenttypes.models import ContentType
 from django.shortcuts import get_object_or_404
+from django.http import Http404
 
 from mptt.exceptions import InvalidMove
 
@@ -338,7 +339,11 @@ class GlobalComponentContactViewSet(HackedComponentContactMixin,
 
     def get_queryset(self):
         gc_id = self.kwargs.get('instance_pk')
-        gc = get_object_or_404(GlobalComponent, id=gc_id)
+        try:
+            gc = get_object_or_404(GlobalComponent, id=gc_id)
+        except ValueError:
+            # Raised when non-numeric instance_pk is given.
+            raise Http404('Global component with id=%s not found' % gc_id)
         return gc.contacts.all()
 
     def list(self, request, *args, **kwargs):
@@ -492,7 +497,11 @@ class GlobalComponentLabelViewSet(viewsets.PDCModelViewSet):
 
     def get_queryset(self):
         gc_id = self.kwargs.get('instance_pk')
-        gc = get_object_or_404(GlobalComponent, id=gc_id)
+        try:
+            gc = get_object_or_404(GlobalComponent, id=gc_id)
+        except ValueError:
+            # Raised when non-numeric instance_pk is given.
+            raise Http404('Global component with id=%s not found' % gc_id)
         labels = gc.labels.all()
         return labels
 
@@ -1078,7 +1087,11 @@ class ReleaseComponentContactViewSet(HackedComponentContactMixin,
 
     def get_queryset(self):
         rc_id = self.kwargs.get("instance_pk", None)
-        release_component = get_object_or_404(ReleaseComponent, pk=rc_id)
+        try:
+            release_component = get_object_or_404(ReleaseComponent, pk=rc_id)
+        except ValueError:
+            # Raised when non-numeric instance_pk is given.
+            raise Http404('Release component with id=%s not found' % rc_id)
         return release_component.contacts.all()
 
     def get_serializer_context(self):
@@ -1128,7 +1141,11 @@ def list(self, request, *args, **kwargs):
         # cannot benefit from DRF built-in features such as pagination.
         rc_id = kwargs.get("instance_pk", None)
         # Release Component object
-        rc = get_object_or_404(ReleaseComponent, pk=rc_id)
+        try:
+            rc = get_object_or_404(ReleaseComponent, pk=rc_id)
+        except ValueError:
+            # Raised when non-numeric instance_pk is given.
+            raise Http404('Release component with id=%s not found' % rc_id)
         gcc_qs = GlobalComponent.objects.get(pk=rc.global_component_id).contacts.all()
         rcc_qs = rc.contacts.all()
         # Contact type based inheritance mechanisms(excerpted from JIRA PDC-184)