fix(audit_log): Prefetch Fk relations to avoid n+1 (#197)

* fix(audit_log): Prefetch Fk relations to avoid n+1

Closes: #174

* test(audit_logs): Add test to check the number of query executed

The test will make sure that we are not executing more than 2 queries
in the API(one for the result and the other one for pagination)

* !fixup: inspect the response to check the count

api/audit/views.py

@@ -44,7 +44,9 @@ def get_queryset(self):
                 self.request.query_params.get("environment")
             )
             q = q & (Q(environment__id=environment_id) | Q(environment=None))
-        return AuditLog.objects.filter(q)
+        return AuditLog.objects.filter(q).select_related(
+            "project", "environment", "author"
+        )
 
     def _get_value_as_int(self, value):
         try:

api/tests/integration/audit/test_audit_logs.py

@@ -0,0 +1,14 @@
+from django.urls import reverse
+from rest_framework import status
+
+
+def test_audit_logs_only_makes_two_queries(
+    admin_client, project, environment, django_assert_num_queries
+):
+    url = reverse("api-v1:audit-list")
+
+    with django_assert_num_queries(2):
+        res = admin_client.get(url, {"project": project})
+
+    assert res.status_code == status.HTTP_200_OK
+    assert res.json()["count"] == 1