Test media in temp folder

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## In development
+
+- Add option to store test media in temp folder (#140).
+
 ## 24.2 (2024-04-16)
 
 - Reinstate setuptools_scm for build (#441).

docs/test.rst

@@ -9,3 +9,5 @@ The `test` module offers extra functions for unit tests.
 
 .. autoclass:: django_marina.test.test_cases.ExtendedTestCase
    :members:
+
+.. autoclass:: django_marina.test.runners.TempMediaDiscoverRunner

src/django_marina/test/runners.py

@@ -0,0 +1,35 @@
+import shutil
+import tempfile
+
+from django.conf import settings
+from django.test.runner import DiscoverRunner
+
+
+class TempMediaMixin:
+    """
+    Mixin to create MEDIA_ROOT in temporary directory and tear down when complete.
+
+    Source: https://www.caktusgroup.com/blog/2013/06/26/media-root-and-django-tests/
+    """
+
+    def setup_test_environment(self):
+        """Create temp directory and update MEDIA_ROOT and default storage."""
+        super().setup_test_environment()
+        settings._original_media_root = settings.MEDIA_ROOT
+        settings._original_file_storage = settings.DEFAULT_FILE_STORAGE
+        self._temp_media = tempfile.mkdtemp()
+        settings.MEDIA_ROOT = self._temp_media
+        settings.DEFAULT_FILE_STORAGE = "django.core.files.storage.FileSystemStorage"
+
+    def teardown_test_environment(self):
+        """Delete temp storage."""
+        super().teardown_test_environment()
+        shutil.rmtree(self._temp_media, ignore_errors=True)
+        settings.MEDIA_ROOT = settings._original_media_root
+        del settings._original_media_root
+        settings.DEFAULT_FILE_STORAGE = settings._original_file_storage
+        del settings._original_file_storage
+
+
+class TempMediaDiscoverRunner(TempMediaMixin, DiscoverRunner):
+    """Default Django DiscoverRunner, modified to write media files to a temp folder."""