test: adding test cases for the export course metadata export storage

cms/djangoapps/export_course_metadata/test_signals.py

@@ -3,11 +3,15 @@ Tests for signals.py
 """
 
 from unittest.mock import patch
+from django.test.utils import override_settings
+from django.conf import settings
 
 from edx_toggles.toggles.testutils import override_waffle_flag
 from xmodule.modulestore.django import SignalHandler
 from xmodule.modulestore.tests.django_utils import SharedModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory, BlockFactory
+from common.djangoapps.util.storage import resolve_storage_backend
+from storages.backends.s3boto3 import S3Boto3Storage
 
 from .signals import export_course_metadata
 from .toggles import EXPORT_COURSE_METADATA_FLAG
@@ -53,3 +57,66 @@ class TestExportCourseMetadata(SharedModuleStoreTestCase):
         patched_storage.save.assert_called_once_with(
             f'course_metadata_export/{self.course_key}.json', patched_content.return_value
         )
+
+    @override_settings(
+        COURSE_METADATA_EXPORT_STORAGE="cms.djangoapps.export_course_metadata.storage.CourseMetadataExportS3Storage",
+        DEFAULT_FILE_STORAGE="django.core.files.storage.FileSystemStorage"
+    )
+    def test_resolve_default_storage(self):
+        """ Ensure the default storage is invoked, even if course export storage is configured """
+        storage = resolve_storage_backend("default")
+        self.assertEqual(storage.__class__.__name__, "FileSystemStorage")
+
+    @override_settings(
+        COURSE_METADATA_EXPORT_STORAGE="cms.djangoapps.export_course_metadata.storage.CourseMetadataExportS3Storage",
+        DEFAULT_FILE_STORAGE="django.core.files.storage.FileSystemStorage",
+        COURSE_METADATA_EXPORT_BUCKET="bucket_name_test"
+    )
+    def test_resolve_happy_path_storage(self):
+        """ Make sure that the correct course export storage is being used """
+        storage = resolve_storage_backend("COURSE_METADATA_EXPORT_STORAGE")
+        self.assertEqual(storage.__class__.__name__, "CourseMetadataExportS3Storage")
+        self.assertEqual(storage.bucket_name, "bucket_name_test")
+
+    def test_resolve_storage_with_no_config(self):
+        """ If no storage setup is defined, we get FileSystemStorage by default """
+        del settings.DEFAULT_FILE_STORAGE
+        del settings.COURSE_METADATA_EXPORT_STORAGE
+        del settings.COURSE_METADATA_EXPORT_BUCKET
+        storage = resolve_storage_backend("COURSE_METADATA_EXPORT_STORAGE")
+        self.assertEqual(storage.__class__.__name__, "FileSystemStorage")
+
+    @override_settings(
+        COURSE_METADATA_EXPORT_STORAGE=None,
+        COURSE_METADATA_EXPORT_BUCKET="bucket_name_test",
+        STORAGES={
+            'COURSE_METADATA_EXPORT_STORAGE': {
+                'BACKEND': 'cms.djangoapps.export_course_metadata.storage.CourseMetadataExportS3Storage',
+                'OPTIONS': {}
+            }
+        }
+    )
+    def test_resolve_storage_using_django5_settings(self):
+        """ Simulating a Django 4 environment using Django 5 Storages configuration """
+        storage = resolve_storage_backend("COURSE_METADATA_EXPORT_STORAGE")
+        self.assertEqual(storage.__class__.__name__, "CourseMetadataExportS3Storage")
+        self.assertEqual(storage.bucket_name, "bucket_name_test")
+
+    @override_settings(
+        STORAGES={
+            'COURSE_METADATA_EXPORT_STORAGE': {
+                'BACKEND': 'storages.backends.s3boto3.S3Boto3Storage',
+                'OPTIONS': {
+                    'bucket_name': 'bucket_name_test'
+                }
+            }
+        }
+    )
+    def test_resolve_storage_using_django5_settings_with_options(self):
+        """ Ensure we call the storage class with the correct parameters and Django 5 setup """
+        del settings.DEFAULT_FILE_STORAGE
+        del settings.COURSE_METADATA_EXPORT_STORAGE
+        del settings.COURSE_METADATA_EXPORT_BUCKET
+        storage = resolve_storage_backend("COURSE_METADATA_EXPORT_STORAGE")
+        self.assertEqual(storage.__class__.__name__, S3Boto3Storage.__name__)
+        self.assertEqual(storage.bucket_name, "bucket_name_test")

common/djangoapps/util/storage.py

@@ -6,14 +6,27 @@ from django.core.files.storage import default_storage
 from django.utils.module_loading import import_string
 
 
-if django.VERSION >= (5, 0):
-    from django.core.files.storage import storages
+def resolve_storage_backend(storage_key, options=None):
+    """
+    Configures and returns a Django `Storage` instance, compatible with both Django 4 and Django 5.
 
+    Main goal:
+        Deprecate the use of `django.core.files.storage.get_storage_class`.
+    How:
+        Replace `get_storage_class` with direct configuration logic,
+        ensuring backward compatibility with both Django 4 and Django 5 storage settings.
+    Returns:
+        An instance of the configured storage backend.
+    Raises:
+        ImportError: If the specified storage class cannot be imported.
+    """
 
-def resolve_storage_backend(storage_key, options={}):
-    storage_path = getattr(settings, storage_key)
+    storage_path = getattr(settings, storage_key, None)
     storages_config = getattr(settings, 'STORAGES', {})
 
+    if options is None:
+        options = {}
+
     if storage_key == "default":
         # Use case 1: Default storage
         # Works consistently across Django 4.2 and 5.x
@@ -29,6 +42,7 @@ def resolve_storage_backend(storage_key, options={}):
         #     "custom": {"BACKEND": "...", "OPTIONS": {...}},
         # }
         # See: https://docs.djangoproject.com/en/5.2/ref/settings/#std-setting-STORAGES
+        from django.core.files.storage import storages
         return storages[storage_key]
 
     if not storage_path and storage_key in storages_config:
@@ -37,7 +51,7 @@ def resolve_storage_backend(storage_key, options={}):
         # Manually load the backend and options
         storage_path = storages_config.get(storage_key, {}).get("BACKEND")
         options = storages_config.get(storage_key, {}).get("OPTIONS", {})
-    
+
     if not storage_path:
         # if no specific storage was resolved, use the default storage
         return default_storage