[bug] Media url fix (#10855)

* Bug fix for getMediaUrl

- Proper check for file type
- Fix "fully_qualified_url" for Attachment model

* Add unit test

* Fix typo

* Fix unit test

---------

Co-authored-by: Matthias Mair <code@mjmair.com>

src/backend/InvenTree/InvenTree/helpers.py

@@ -16,7 +16,7 @@ from django.conf import settings
 from django.contrib.staticfiles.storage import StaticFilesStorage
 from django.core.exceptions import FieldError, ValidationError
 from django.core.files.storage import default_storage
-from django.db.models.fields.files import ImageFieldFile
+from django.db.models.fields.files import FieldFile, ImageFieldFile
 from django.http import StreamingHttpResponse
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
@@ -176,10 +176,14 @@ def constructPathString(path: list[str], max_chars: int = 250) -> str:
     return pathstring
 
 
-def getMediaUrl(file: StdImageFieldFile | ImageFieldFile, name: str | None = None):
+def getMediaUrl(
+    file: FieldFile | ImageFieldFile | StdImageFieldFile, name: str | None = None
+):
     """Return the qualified access path for the given file, under the media directory."""
-    if not isinstance(file, StdImageFieldFile):
+    if not isinstance(file, (FieldFile, ImageFieldFile, StdImageFieldFile)):
-        raise ValueError('file_obj must be an instance of StdImageFieldFile')
+        raise TypeError(
+            'file must be one of FileField, ImageFileField, StdImageFieldFile'
+        )
     if name is not None:
         file = regenerate_imagefile(file, name)
     if settings.STORAGE_TARGET == StorageBackends.S3:

src/backend/InvenTree/InvenTree/tests.py

@@ -702,7 +702,7 @@ class TestHelpers(TestCase):
     def testMediaUrl(self):
         """Test getMediaUrl."""
         # Str should not work
-        with self.assertRaises(ValueError):
+        with self.assertRaises(TypeError):
             helpers.getMediaUrl('xx/yy.png')  # type: ignore
 
         # Correct usage

src/backend/InvenTree/common/models.py

@@ -2034,7 +2034,7 @@ class Attachment(InvenTree.models.MetadataMixin, InvenTree.models.InvenTreeModel
         if self.attachment:
             import InvenTree.helpers_model
 
-            media_url = InvenTree.helpers.getMediaUrl(self.attachment.url)
+            media_url = InvenTree.helpers.getMediaUrl(self.attachment)
             return InvenTree.helpers_model.construct_absolute_url(media_url)
 
         return ''

src/backend/InvenTree/common/tests.py

@@ -202,6 +202,21 @@ class AttachmentTest(InvenTreeAPITestCase):
         self.assignRole('part.delete')
         self.delete(url, expected_code=204)
 
+    def test_fully_qualified_url(self):
+        """Test that the fully qualified URL is returned correctly."""
+        part = Part.objects.first()
+
+        attachment = Attachment.objects.create(
+            attachment=self.generate_file('test.txt'),
+            comment='Testing filename: test.txt',
+            model_type='part',
+            model_id=part.pk,
+        )
+
+        url = attachment.fully_qualified_url()
+        self.assertIs(type(url), str)
+        self.assertIn(f'/media/attachments/part/{part.pk}/test', url)
+
 
 class SettingsTest(InvenTreeTestCase):
     """Tests for the 'settings' model."""