From 4c42a15fa1a1d9b474a866340baa15052689dede Mon Sep 17 00:00:00 2001
From: Bryan Van Deusen <bryan.vandeusen@fabledsword.com>
Date: Sat, 6 Jun 2026 23:10:46 -0400
Subject: [PATCH] fix(patreon): a missing media file_name is a URL-basename
 fallback, not API drift
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The native client treated a gallery image without `file_name` as schema drift
and raised "Patreon API changed — ingester needs update", failing the whole walk
(operator-flagged 2026-06-07: BlenderKnight post 73665615, kind=images). But the
resource had a valid URL, and the code already derives a filename from the URL
basename right below the raise — the same fallback gallery-dl uses. Patreon
legitimately serves some images without file_name, so this isn't drift.

Drop the require_file_name gate from _media_item: file_name is now optional for
every kind (images/attachments/postfile), falling back to the URL basename.
Genuine drift still raises — no resolvable URL, or a media id referenced by a
relationship but absent from `included`. Test updated to assert the fallback.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 backend/app/services/patreon_client.py | 20 +++++++-------------
 tests/test_patreon_client.py           | 13 ++++++++-----
 2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/backend/app/services/patreon_client.py b/backend/app/services/patreon_client.py
index 98d8134..b896c4b 100644
--- a/backend/app/services/patreon_client.py
+++ b/backend/app/services/patreon_client.py
@@ -405,21 +405,19 @@ class PatreonClient:
                     return candidate
         return None
 
-    def _media_item(
-        self, attrs: dict, kind: str, post_id: str, *, require_file_name: bool
-    ) -> MediaItem:
+    def _media_item(self, attrs: dict, kind: str, post_id: str) -> MediaItem:
         url = self._media_url(attrs)
         if not url:
             raise PatreonDriftError(
                 f"Patreon media (post {post_id}, kind={kind}) had no resolvable URL "
                 f"(no download_url / image_urls)"
             )
+        # file_name is OPTIONAL: Patreon legitimately serves some gallery images
+        # without it (operator-flagged 2026-06-07, BlenderKnight post 73665615),
+        # and the URL basename is a fine fallback — the same thing gallery-dl
+        # uses. A genuine schema change shows up as no URL (above) or a media id
+        # absent from `included` (caller), not a missing name.
         file_name = attrs.get("file_name")
-        if require_file_name and not (isinstance(file_name, str) and file_name):
-            raise PatreonDriftError(
-                f"Patreon media resource (post {post_id}, kind={kind}) missing "
-                f"'file_name'"
-            )
         filename = file_name if isinstance(file_name, str) and file_name else _basename_from_url(url)
         return MediaItem(
             url=url,
@@ -452,11 +450,7 @@ class PatreonClient:
                         f"Patreon post {post_id} references media {mid} "
                         f"({rel_name}) not present in 'included'"
                     )
-                items.append(
-                    self._media_item(
-                        media_attrs, kind, post_id, require_file_name=True
-                    )
-                )
+                items.append(self._media_item(media_attrs, kind, post_id))
 
         # 1. gallery images
         _resolve_rel("images", "images")
diff --git a/tests/test_patreon_client.py b/tests/test_patreon_client.py
index 0426147..fe46b91 100644
--- a/tests/test_patreon_client.py
+++ b/tests/test_patreon_client.py
@@ -159,9 +159,10 @@ def test_non_list_data_raises_drift(client):
         client._validate_response({"data": {"id": "1"}})
 
 
-def test_media_missing_file_name_raises_drift(client):
-    # A media resource referenced by a gallery relationship but lacking
-    # file_name is drift from the contract.
+def test_media_missing_file_name_falls_back_to_url_basename(client):
+    # A gallery image with a valid URL but no file_name is NOT drift — Patreon
+    # serves these (operator-flagged 2026-06-07, BlenderKnight post 73665615);
+    # fall back to the URL basename like gallery-dl does.
     post = {
         "id": "2000",
         "type": "post",
@@ -175,8 +176,10 @@ def test_media_missing_file_name_raises_drift(client):
             + "/x.jpg"
         }
     }
-    with pytest.raises(PatreonDriftError):
-        client.extract_media(post, index)
+    items = client.extract_media(post, index)
+    assert len(items) == 1
+    assert items[0].filename == "x.jpg"
+    assert items[0].kind == "images"
 
 
 def test_media_referenced_but_absent_raises_drift(client):