fix: fix various issues before merging

api/tests/test_pdf_service_images.py

@@ -1,10 +1,64 @@
+from io import BytesIO
 import unittest
 from unittest.mock import AsyncMock, patch, MagicMock
 
+from PIL import Image
+
 from api.services.pdf_service import PDFService
 
 
 class PDFServiceImagesTest(unittest.IsolatedAsyncioTestCase):
+    @patch("api.services.pdf_service.ReportLabImage")
+    @patch("api.services.pdf_service.httpx.AsyncClient")
+    @patch("api.services.pdf_service.TencentCosStorageService")
+    async def test_generate_pdf_preserves_image_aspect_ratio(
+        self,
+        storage_cls,
+        async_client_cls,
+        reportlab_image_cls,
+    ):
+        image_buffer = BytesIO()
+        Image.new("RGB", (2, 1), color="white").save(image_buffer, format="PNG")
+        png_bytes = image_buffer.getvalue()
+        mock_response = MagicMock()
+        mock_response.content = png_bytes
+        mock_response.raise_for_status = MagicMock()
+
+        mock_client = AsyncMock()
+        mock_client.get.return_value = mock_response
+        async_client_cls.return_value.__aenter__ = AsyncMock(return_value=mock_client)
+        async_client_cls.return_value.__aexit__ = AsyncMock(return_value=False)
+        storage = MagicMock()
+        storage.get_download_url.return_value = "https://signed.example.com/0.png?sig=123"
+        storage_cls.from_env.return_value = storage
+        reportlab_image_cls.return_value = MagicMock()
+
+        service = PDFService()
+        book = type("BookStub", (), {"title": "我的回忆录"})()
+        chapter = type(
+            "ChapterStub",
+            (),
+            {
+                "title": "童年的夏天",
+                "content": "{{{{IMAGE:南方小镇的青石板路}}}}",
+                "images": [
+                    {
+                        "index": 0,
+                        "placeholder": "{{{{IMAGE:南方小镇的青石板路}}}}",
+                        "url": "https://life-echo-dev-1319381411.cos.ap-shanghai.myqcloud.com/memoirs/u1/c1/0.png",
+                        "storage_key": "memoirs/u1/c1/0.png",
+                        "status": "completed",
+                    }
+                ],
+            },
+        )()
+
+        await service.generate_pdf(book, [chapter])
+
+        _, kwargs = reportlab_image_cls.call_args
+        self.assertAlmostEqual(kwargs["width"], 5 * 72)
+        self.assertAlmostEqual(kwargs["height"], 2.5 * 72)
+
     @patch("api.services.pdf_service.httpx.AsyncClient")
     @patch("api.services.pdf_service.TencentCosStorageService")
     async def test_generate_pdf_embeds_completed_images_and_removes_placeholders(