Raise NotConfigured when FILES_STORE or IMAGES_STORE is None or empty (#6969)

scrapy/pipelines/files.py

@@ -450,9 +450,16 @@ class FilesPipeline(MediaPipeline):
         *,
         crawler: Crawler | None = None,
     ):
-        store_uri = _to_string(store_uri)
-        if not store_uri:
-            raise NotConfigured
+        if not (store_uri and (store_uri := _to_string(store_uri))):
+            from scrapy.pipelines.images import ImagesPipeline  # noqa: PLC0415
+
+            setting_name = (
+                "IMAGES_STORE" if isinstance(self, ImagesPipeline) else "FILES_STORE"
+            )
+            raise NotConfigured(
+                f"{setting_name} setting must be set to a valid path (not empty) "
+                f"to enable {self.__class__.__name__}."
+            )
 
         if crawler is not None:
             if settings is not None:

tests/test_pipeline_files.py

@@ -20,6 +20,7 @@ import pytest
 from itemadapter import ItemAdapter
 from twisted.internet.defer import inlineCallbacks
 
+from scrapy.exceptions import NotConfigured
 from scrapy.http import Request, Response
 from scrapy.item import Field, Item
 from scrapy.pipelines.files import (
@@ -29,6 +30,7 @@ from scrapy.pipelines.files import (
     GCSFilesStore,
     S3FilesStore,
 )
+from scrapy.settings import Settings
 from scrapy.utils.spider import DefaultSpider
 from scrapy.utils.test import get_crawler
 from tests.mockserver.ftp import MockFTPServer
@@ -804,3 +806,14 @@ class TestBuildFromCrawler:
             assert len(w) == 0
             assert pipe.store
             assert pipe._from_crawler_called
+
+
+@pytest.mark.parametrize("store", [None, ""])
+def test_files_pipeline_raises_notconfigured_when_files_store_invalid(store):
+    settings = Settings()
+    settings.clear()
+    settings.set("FILES_STORE", store, priority="cmdline")
+    crawler = get_crawler(settings_dict=settings)
+
+    with pytest.raises(NotConfigured):
+        FilesPipeline.from_crawler(crawler)