feat: 修改 400问题

server/tests/test_export.py

@@ -8,6 +8,8 @@ import zipfile
 from pathlib import Path
 from unittest.mock import AsyncMock, patch
 
+from fastapi import HTTPException
+
 SERVER_DIR = Path(__file__).resolve().parents[1]
 if str(SERVER_DIR) not in sys.path:
     sys.path.insert(0, str(SERVER_DIR))
@@ -16,6 +18,23 @@ from api.export import ExportImageItem, ExportImagesRequest, export_image, expor
 
 
 class ExportImageTests(unittest.IsolatedAsyncioTestCase):
+    async def test_extensionless_image_with_generic_mime_can_be_downloaded(self) -> None:
+        image = ExportImageItem(url="https://example.com/assets/opaque-key", key="upload")
+        png = b"\x89PNG\r\n\x1a\n" + b"image bytes"
+        with patch("api.export._download", new=AsyncMock(return_value=(png, "application/octet-stream"))):
+            response = await export_image(image)
+
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.media_type, "image/png")
+        self.assertIn('filename="upload.png"', response.headers["content-disposition"])
+
+    async def test_extensionless_non_image_is_rejected(self) -> None:
+        image = ExportImageItem(url="https://example.com/assets/opaque-key")
+        with patch("api.export._download", new=AsyncMock(return_value=(b"not an image", "application/octet-stream"))):
+            with self.assertRaises(HTTPException) as raised:
+                await export_image(image)
+        self.assertEqual(raised.exception.status_code, 400)
+
     async def test_chinese_filename_uses_rfc5987_header(self) -> None:
         image = ExportImageItem(
             url="https://example.com/image.png",