PPHA-409: Cleanup family age when diagnosed when answering family history

lung_cancer_screening/questions/models/family_history_lung_cancer_response.py

@@ -1,4 +1,6 @@
 from django.db import models
+from django.db.models.signals import post_save
+from django.dispatch import receiver
 
 from .base import BaseModel
 from .response_set import ResponseSet
@@ -12,3 +14,13 @@ class FamilyHistoryLungCancerValues(models.TextChoices):
 class FamilyHistoryLungCancerResponse(BaseModel):
     response_set = models.OneToOneField(ResponseSet, on_delete=models.CASCADE, related_name='family_history_lung_cancer')
     value = models.CharField(max_length=1, choices=FamilyHistoryLungCancerValues.choices)
+
+
+@receiver(post_save, sender=FamilyHistoryLungCancerResponse)
+def remove_relatives_age_when_diagnosed_if_not_yes(sender, instance, **kwargs):
+    if (
+        instance.value != FamilyHistoryLungCancerValues.YES
+        and instance.response_set
+        and hasattr(instance.response_set, "relatives_age_when_diagnosed")
+    ):
+        instance.response_set.relatives_age_when_diagnosed.delete()

lung_cancer_screening/questions/tests/unit/models/test_family_history_lung_cancer_response.py

@@ -1,9 +1,17 @@
 from django.test import TestCase, tag
 
 from ...factories.response_set_factory import ResponseSetFactory
-from ...factories.family_history_lung_cancer_response_factory import FamilyHistoryLungCancerResponseFactory, FamilyHistoryLungCancerValues
+from ...factories.family_history_lung_cancer_response_factory import (
+    FamilyHistoryLungCancerResponseFactory,
+)
+from ...factories.relatives_age_when_diagnosed_response_factory import (
+    RelativesAgeWhenDiagnosedResponseFactory
+)
 
-from ....models.family_history_lung_cancer_response import FamilyHistoryLungCancerResponse
+from ....models.family_history_lung_cancer_response import (
+    FamilyHistoryLungCancerResponse,
+    FamilyHistoryLungCancerValues,
+)
 
 @tag("FamilyHistoryLungCancer")
 class TestFamilyHistoryLungCancerResponse(TestCase):
@@ -16,19 +24,59 @@ def test_has_a_valid_factory(self):
 
 
     def test_has_response_set_as_foreign_key(self):
-        response_set = ResponseSetFactory()
         response = FamilyHistoryLungCancerResponse.objects.create(
-            response_set=response_set,
+            response_set=self.response_set,
             value=FamilyHistoryLungCancerValues.NO
         )
 
-        self.assertEqual(response.response_set, response_set)
+        self.assertEqual(response.response_set, self.response_set)
 
     def test_has_value_as_string(self):
-        response_set = ResponseSetFactory()
         response = FamilyHistoryLungCancerResponse.objects.create(
-            response_set=response_set,
+            response_set=self.response_set,
             value=FamilyHistoryLungCancerValues.NO
         )
 
         self.assertIsInstance(response.value, str)
+
+
+    def test_deletes_family_age_when_diagnosed_if_response_is_no(self):
+        RelativesAgeWhenDiagnosedResponseFactory.create(response_set=self.response_set)
+
+        self.assertTrue(hasattr(self.response_set, "relatives_age_when_diagnosed"))
+
+        FamilyHistoryLungCancerResponse.objects.create(
+            response_set=self.response_set,
+            value=FamilyHistoryLungCancerValues.NO
+        )
+
+        self.response_set.refresh_from_db()
+        self.assertFalse(hasattr(self.response_set, "relatives_age_when_diagnosed"))
+
+
+    def test_deletes_family_age_when_diagnosed_if_response_is_unknown(self):
+        RelativesAgeWhenDiagnosedResponseFactory.create(response_set=self.response_set)
+
+        self.assertTrue(hasattr(self.response_set, "relatives_age_when_diagnosed"))
+
+        FamilyHistoryLungCancerResponse.objects.create(
+            response_set=self.response_set,
+            value=FamilyHistoryLungCancerValues.UNKNOWN
+        )
+
+        self.response_set.refresh_from_db()
+        self.assertFalse(hasattr(self.response_set, "relatives_age_when_diagnosed"))
+
+
+    def test_does_not_delete_family_age_when_diagnosed_if_response_is_yes(self):
+        RelativesAgeWhenDiagnosedResponseFactory.create(response_set=self.response_set)
+
+        self.assertTrue(hasattr(self.response_set, "relatives_age_when_diagnosed"))
+
+        FamilyHistoryLungCancerResponse.objects.create(
+            response_set=self.response_set,
+            value=FamilyHistoryLungCancerValues.YES
+        )
+
+        self.response_set.refresh_from_db()
+        self.assertTrue(hasattr(self.response_set, "relatives_age_when_diagnosed"))