test: bringing ModelPublisherTask usage closer to how it is used in r…

…eal life

sample_project/sample_app/apps.py

@@ -6,3 +6,4 @@ class SampleAppConfig(AppConfig):
 
     def ready(self):
         from sample_project.sample_app import tasks  # noqa: F401
+        from sample_project.sample_app import signals  # noqa: F401

sample_project/sample_app/signals.py

@@ -0,0 +1,14 @@
+from django.db.models.signals import post_save, post_delete
+from django.dispatch import receiver
+
+from sample_app import models, tasks
+
+
+@receiver(post_save, sender=models.Person)
+def publish_person(sender, instance: models.Person, **kwargs):
+    tasks.PublishPersonTask.sync(obj=instance, event="saved")
+
+
+@receiver(post_delete, sender=models.Person)
+def delete_person(sender, instance: models.Person, **kwargs):
+    tasks.PublishPersonTask.sync(obj=instance, event="deleted")

sample_project/sample_app/tasks.py

@@ -91,12 +91,12 @@ def revert(cls, data: dict):
 
 class PublishPersonTask(ModelPublisherTask):
     @classmethod
-    def build_message_content(cls, obj: Model, **kwargs) -> dict:
-        return {"name": obj.name}
+    def build_message_content(cls, obj: Model, event: str, **kwargs) -> dict:
+        return {"id": obj.pk, "name": obj.name}
 
     @classmethod
-    def build_message_attributes(cls, obj: Model, **kwargs) -> dict[str, str]:
-        return {"any-custom-attribute": "yay!"}
+    def build_message_attributes(cls, obj: Model, event: str, **kwargs) -> dict[str, str]:
+        return {"any-custom-attribute": "yay!", "event": event}
 
 
 class DummyRoutineTask(RoutineTask):

sample_project/sample_app/tests/tests_views/tests_publisher_task_views.py

@@ -1,20 +1,53 @@
 from unittest.mock import patch, ANY
 
 from django.test import TransactionTestCase
+from gcp_pilot.mocker import patch_auth
+
+from sample_app import models
+import json
 
 
 class PublisherTaskTest(TransactionTestCase):
-    def test_propagate_headerss(self):
+    def setUp(self):
+        super().setUp()
+        auth = patch_auth()
+        auth.start()
+        self.addCleanup(auth.stop)
+
+    def test_propagate_headers(self):
         url = "/create-person"
         data = {"name": "Harry Potter"}
         headers = {
             "traceparent": "trace-this-potato",
             "another-random-header": "please-do-not-propagate-this",
         }
         django_headers = {f"HTTP_{key.upper()}": value for key, value in headers.items()}
-        with patch("django_cloud_tasks.tasks.publisher_task.CloudPublisher") as publisher:
-            self.client.post(path=url, data=data, content_type="application/json", **django_headers)
+        with patch("django_cloud_tasks.tasks.publisher_task.CloudPublisher.publish") as publish:
+            result = self.client.post(path=url, data=data, content_type="application/json", **django_headers)
+
+        self.assertEqual(201, result.status_code)
+        expected_message = json.dumps(
+            {"id": result.json()["pk"], "name": "Harry Potter", "_http_headers": {"Traceparent": "trace-this-potato"}}
+        )
+        expected_attributes = {"any-custom-attribute": "yay!", "event": "saved"}
+        publish.assert_called_once_with(message=expected_message, topic_id=ANY, attributes=expected_attributes)
+
+    def test_usage_inside_transaction(self):
+        with patch("django_cloud_tasks.tasks.publisher_task.CloudPublisher.publish"):
+            existing = models.Person.objects.create(name="Potter Harry")
+
+        url = "/replace-person"
+        data = {"name": "Harry Potter", "person_to_replace_id": existing.pk}
+        with patch("django_cloud_tasks.tasks.publisher_task.CloudPublisher.publish") as publish:
+            result = self.client.post(path=url, data=data, content_type="application/json")
+
+        self.assertEqual(201, result.status_code)
+        self.assertEqual(2, publish.call_count)
+
+        expected_message = json.dumps({"id": existing.pk, "name": "Potter Harry"})
+        expected_attributes = {"any-custom-attribute": "yay!", "event": "deleted"}
+        publish.assert_any_call(message=expected_message, topic_id=ANY, attributes=expected_attributes)
 
-        expected_message = '{"name": "Harry Potter", "_http_headers": {"Traceparent": "trace-this-potato"}}'
-        publisher_instance = publisher.return_value
-        publisher_instance.publish.assert_called_once_with(message=expected_message, topic_id=ANY, attributes=ANY)
+        expected_message = json.dumps({"id": result.json()["pk"], "name": "Harry Potter"})
+        expected_attributes = {"any-custom-attribute": "yay!", "event": "saved"}
+        publish.assert_any_call(message=expected_message, topic_id=ANY, attributes=expected_attributes)

sample_project/sample_app/views.py

@@ -1,14 +1,28 @@
 import json
+from django.db import transaction
 
 from django.http import JsonResponse
 from django.views import View
 
 from sample_app import models
-from sample_app.tasks import PublishPersonTask
 
 
 class PersonCreateView(View):
     def post(self, request, *args, **kwargs):
-        person = models.Person.objects.create(**json.loads(request.body))
-        PublishPersonTask.sync(obj=person)
-        return JsonResponse(status=201, data={"status": "published"})
+        person = models.Person(**json.loads(request.body))
+        person.save()
+        return JsonResponse(status=201, data={"status": "published", "pk": person.pk})
+
+
+class PersonReplaceView(View):
+    @transaction.atomic
+    def post(self, request, *args, **kwargs):
+        payload = json.loads(request.body)
+        person_to_replace_id = payload.pop("person_to_replace_id")
+
+        to_delete = models.Person.objects.get(pk=person_to_replace_id)
+        to_delete.delete()
+
+        person = models.Person(**payload)
+        person.save()
+        return JsonResponse(status=201, data={"status": "published", "pk": person.pk})

sample_project/urls.py

@@ -5,4 +5,5 @@
 urlpatterns = [
     path("", include("django_cloud_tasks.urls")),
     path("create-person", views.PersonCreateView.as_view()),
+    path("replace-person", views.PersonReplaceView.as_view()),
 ]