From a116f2c14148f84593cdd09b98cd40665ffe9955 Mon Sep 17 00:00:00 2001
From: Matthew Elwell <matthew.elwell@flagsmith.com>
Date: Thu, 13 Feb 2025 12:58:40 +0000
Subject: [PATCH] fix(feature-export): handle unsuccessful feature export
 download exception (#5086)

---
 api/features/import_export/views.py           | 10 +++++-
 .../test_unit_features_import_export_views.py | 31 ++++++++++++++++++-
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/api/features/import_export/views.py b/api/features/import_export/views.py
index 42b162ed7ae7..79208c6a3006 100644
--- a/api/features/import_export/views.py
+++ b/api/features/import_export/views.py
@@ -4,7 +4,7 @@
 from django.db.models import QuerySet
 from django.http import Http404
 from drf_yasg.utils import swagger_auto_schema
-from rest_framework import permissions
+from rest_framework import permissions, serializers
 from rest_framework.decorators import api_view, permission_classes
 from rest_framework.generics import ListAPIView, get_object_or_404
 from rest_framework.request import Request
@@ -12,6 +12,7 @@
 
 from environments.models import Environment
 
+from .constants import SUCCESS
 from .models import (
     FeatureExport,
     FeatureImport,
@@ -73,6 +74,13 @@ def feature_import(request: Request, environment_id: int) -> Response:
 def download_feature_export(request: Request, feature_export_id: int) -> Response:
     feature_export = get_object_or_404(FeatureExport, id=feature_export_id)
 
+    if feature_export.status != SUCCESS:
+        raise serializers.ValidationError(
+            {
+                "detail": f"Unable to download export with status '{feature_export.status}'."
+            }
+        )
+
     response = Response(
         json.loads(feature_export.data), content_type="application/json"
     )
diff --git a/api/tests/unit/features/import_export/test_unit_features_import_export_views.py b/api/tests/unit/features/import_export/test_unit_features_import_export_views.py
index 55dd5551674d..c1282dbd2b0d 100644
--- a/api/tests/unit/features/import_export/test_unit_features_import_export_views.py
+++ b/api/tests/unit/features/import_export/test_unit_features_import_export_views.py
@@ -10,7 +10,12 @@
 
 from environments.models import Environment
 from environments.permissions.models import UserEnvironmentPermission
-from features.import_export.constants import OVERWRITE_DESTRUCTIVE, PROCESSING
+from features.import_export.constants import (
+    FAILED,
+    OVERWRITE_DESTRUCTIVE,
+    PROCESSING,
+    SUCCESS,
+)
 from features.import_export.models import (
     FeatureExport,
     FeatureImport,
@@ -136,6 +141,7 @@ def test_download_feature_export(
     feature_export = FeatureExport.objects.create(
         environment=environment,
         data='[{"feature": "data"}]',
+        status=SUCCESS,
     )
     url = reverse("api-v1:features:download-feature-export", args=[feature_export.id])
     # When
@@ -166,6 +172,29 @@ def test_download_feature_export_unauthorized(
     assert response.status_code == 403
 
 
+@pytest.mark.parametrize("status", (PROCESSING, FAILED))
+def test_cannot_download_non_success_feature_export(
+    admin_client_new: APIClient,
+    environment: Environment,
+    status: str,
+) -> None:
+    # Given
+    feature_export = FeatureExport.objects.create(
+        environment=environment,
+        status=status,
+    )
+    url = reverse("api-v1:features:download-feature-export", args=[feature_export.id])
+
+    # When
+    response = admin_client_new.get(url)
+
+    # Then
+    assert response.status_code == 400
+    assert response.json() == {
+        "detail": f"Unable to download export with status '{status}'."
+    }
+
+
 def test_feature_import(
     admin_client: APIClient,
     environment: Environment,