feat: Return transient traits explicitly (#4375)

api/environments/identities/models.py

@@ -219,9 +219,11 @@ def generate_traits(self, trait_data_items, persist=False):
                 identity=self,
                 **Trait.generate_trait_value_data(trait_value),
             )
-            trait_models.append(trait)
-            if not trait_data_item.get("transient"):
+            if trait_data_item.get("transient"):
+                trait.transient = True
+            else:
                 trait_models_to_persist.append(trait)
+            trait_models.append(trait)
 
         if persist:
             Trait.objects.bulk_create(trait_models_to_persist)
@@ -252,13 +254,13 @@ def update_traits(
             transient = trait_data_item.get("transient")
 
             if transient:
-                transient_traits.append(
-                    Trait(
-                        **Trait.generate_trait_value_data(trait_value),
-                        trait_key=trait_key,
-                        identity=self,
-                    )
+                trait = Trait(
+                    **Trait.generate_trait_value_data(trait_value),
+                    trait_key=trait_key,
+                    identity=self,
                 )
+                trait.transient = True
+                transient_traits.append(trait)
                 continue
 
             if trait_value is None:
@@ -304,7 +306,7 @@ def update_traits(
         # See: https://github.com/Flagsmith/flagsmith/issues/370
         Trait.objects.bulk_create(new_traits, ignore_conflicts=True)
 
-        # return the full list of traits for this identity by refreshing from the db
+        # return the full list of traits for this identity
         # override persisted traits by transient traits in case of key collisions
         return [
             *{

api/environments/identities/traits/models.py

@@ -57,6 +57,14 @@ def natural_key(self):
     def trait_value(self):
         return self.get_trait_value()
 
+    @property
+    def transient(self) -> bool:
+        return getattr(self, "_transient", False)
+
+    @transient.setter
+    def transient(self, transient: bool) -> None:
+        self._transient = transient
+
     def get_trait_value(self):
         try:
             value_type = self.value_type

api/environments/identities/traits/serializers.py

@@ -22,7 +22,7 @@ def get_trait_value(obj):
 
 class TraitSerializerBasic(serializers.ModelSerializer):
     trait_value = TraitValueField(allow_null=True)
-    transient = serializers.BooleanField(default=False, write_only=True)
+    transient = serializers.BooleanField(default=False)
 
     class Meta:
         model = Trait

api/tests/integration/environments/identities/test_integration_identities.py

@@ -284,8 +284,9 @@ def test_get_feature_states_for_identity__transient_trait__segment_match_expecte
     url = reverse("api-v1:sdk-identities")
 
     # When
-    # flags are requested for a new transient identity
+    # flags are requested for a new identity
     # that matches the segment
+    # with a transient trait
     response = sdk_client.post(
         url,
         data=json.dumps(
@@ -310,6 +311,20 @@ def test_get_feature_states_for_identity__transient_trait__segment_match_expecte
     # Then
     assert response.status_code == status.HTTP_200_OK
     response_json = response.json()
+    assert response_json["traits"] == [
+        {
+            "id": mock.ANY,
+            "trait_key": segment_condition_property,
+            "trait_value": segment_condition_value,
+            "transient": True,
+        },
+        {
+            "id": mock.ANY,
+            "trait_key": "persistent",
+            "trait_value": "trait value",
+            "transient": False,
+        },
+    ]
     assert (
         flag_data := next(
             (
@@ -322,3 +337,54 @@ def test_get_feature_states_for_identity__transient_trait__segment_match_expecte
     )
     assert flag_data["enabled"] is True
     assert flag_data["feature_state_value"] == "segment override"
+
+
+def test_get_feature_states_for_identity__transient_trait__existing_identity__return_expected(
+    sdk_client: APIClient,
+    identity_identifier: str,
+    identity: int,
+) -> None:
+    # Given
+    url = reverse("api-v1:sdk-identities")
+
+    # When
+    # flags are requested for an existing identity
+    # with a transient trait
+    response = sdk_client.post(
+        url,
+        data=json.dumps(
+            {
+                "identifier": identity_identifier,
+                "traits": [
+                    {
+                        "trait_key": "transient",
+                        "trait_value": "trait value",
+                        "transient": True,
+                    },
+                    {
+                        "trait_key": "persistent",
+                        "trait_value": "trait value",
+                    },
+                ],
+            }
+        ),
+        content_type="application/json",
+    )
+
+    # Then
+    assert response.status_code == status.HTTP_200_OK
+    response_json = response.json()
+    assert response_json["traits"] == [
+        {
+            "id": mock.ANY,
+            "trait_key": "persistent",
+            "trait_value": "trait value",
+            "transient": False,
+        },
+        {
+            "id": mock.ANY,
+            "trait_key": "transient",
+            "trait_value": "trait value",
+            "transient": True,
+        },
+    ]

api/tests/unit/environments/identities/test_unit_identities_views.py

@@ -1176,13 +1176,17 @@ def test_post_identities__transient_traits__no_persistence(
 ) -> None:
     # Given
     identifier = "transient"
-    trait_key = "trait_key"
+    transient_trait_key = "trait_key"
+    non_transient_trait_key = "other"
 
     api_client.credentials(HTTP_X_ENVIRONMENT_KEY=environment.api_key)
     url = reverse("api-v1:sdk-identities")
     data = {
         "identifier": identifier,
-        "traits": [{"trait_key": trait_key, "trait_value": "bar", "transient": True}],
+        "traits": [
+            {"trait_key": transient_trait_key, "trait_value": "bar", "transient": True},
+            {"trait_key": non_transient_trait_key, "trait_value": "value"},
+        ],
     }
 
     # When
@@ -1193,7 +1197,8 @@ def test_post_identities__transient_traits__no_persistence(
     # Then
     assert response.status_code == status.HTTP_200_OK
     assert Identity.objects.filter(identifier=identifier).exists()
-    assert not Trait.objects.filter(trait_key=trait_key).exists()
+    assert Trait.objects.filter(trait_key=non_transient_trait_key).exists()
+    assert not Trait.objects.filter(trait_key=transient_trait_key).exists()
 
 
 def test_user_with_view_identities_permission_can_retrieve_identity(