test(sns-media): 补充朋友圈图片缓存优先回归测试

- 覆盖本地缓存命中时不调用远程下载

- 覆盖本地缓存未命中时再回退到远程解密

tests/test_sns_media_route_weflow_default.py

@@ -14,25 +14,68 @@ from wechat_decrypt_tool.routers import sns  # noqa: E402  pylint: disable=wrong
 
 
 class TestSnsMediaRouteWeFlowDefault(unittest.TestCase):
-    def test_route_stops_after_remote_miss_by_default(self):
+    def test_route_prefers_local_cache_before_remote(self):
         with TemporaryDirectory() as td:
             account_dir = Path(td) / "acc"
             account_dir.mkdir(parents=True, exist_ok=True)
+            local_path = account_dir / "local.jpg"
+            payload = b"\xff\xd8\xff\x00localjpeg"
+            local_path.write_bytes(payload)
 
             with mock.patch("wechat_decrypt_tool.routers.sns._resolve_account_dir", return_value=account_dir):
-                with mock.patch("wechat_decrypt_tool.routers.sns._try_fetch_and_decrypt_sns_remote", return_value=None):
-                    with self.assertRaises(sns.HTTPException) as ctx:
-                        asyncio.run(
-                            sns.get_sns_media(
-                                account="acc",
-                                url="https://mmsns.qpic.cn/sns/test/0",
-                                key="123",
-                                token="tkn",
-                                use_cache=1,
-                            )
-                        )
+                with mock.patch("wechat_decrypt_tool.routers.sns._resolve_account_wxid_dir", return_value=Path(td) / "wxid"):
+                    with mock.patch("wechat_decrypt_tool.routers.sns._resolve_sns_cached_image_path", return_value=str(local_path)):
+                        with mock.patch("wechat_decrypt_tool.routers.sns._read_and_maybe_decrypt_media", return_value=(payload, "image/jpeg")):
+                            with mock.patch("wechat_decrypt_tool.routers.sns._try_fetch_and_decrypt_sns_remote") as remote:
+                                resp = asyncio.run(
+                                    sns.get_sns_media(
+                                        account="acc",
+                                        create_time=1,
+                                        width=1,
+                                        height=1,
+                                        url="https://mmsns.qpic.cn/sns/test/0",
+                                        key="123",
+                                        token="tkn",
+                                        use_cache=1,
+                                    )
+                                )
 
-        self.assertEqual(ctx.exception.status_code, 404)
+        remote.assert_not_called()
+        self.assertEqual(resp.status_code, 200)
+        self.assertEqual(resp.body, payload)
+        self.assertEqual(resp.headers.get("X-SNS-Source"), "local-cache")
+
+    def test_route_falls_back_to_remote_when_local_cache_misses(self):
+        with TemporaryDirectory() as td:
+            account_dir = Path(td) / "acc"
+            account_dir.mkdir(parents=True, exist_ok=True)
+            remote_resp = sns.Response(content=b"remote", media_type="image/jpeg")
+            remote_resp.headers["X-SNS-Source"] = "remote-decrypt"
+
+            with mock.patch("wechat_decrypt_tool.routers.sns._resolve_account_dir", return_value=account_dir):
+                with mock.patch("wechat_decrypt_tool.routers.sns._resolve_account_wxid_dir", return_value=Path(td) / "wxid"):
+                    with mock.patch("wechat_decrypt_tool.routers.sns._resolve_sns_cached_image_path", return_value=None):
+                        with mock.patch(
+                            "wechat_decrypt_tool.routers.sns._try_fetch_and_decrypt_sns_remote",
+                            return_value=remote_resp,
+                        ) as remote:
+                            resp = asyncio.run(
+                                sns.get_sns_media(
+                                    account="acc",
+                                    create_time=1,
+                                    width=1,
+                                    height=1,
+                                    url="https://mmsns.qpic.cn/sns/test/0",
+                                    key="123",
+                                    token="tkn",
+                                    use_cache=1,
+                                )
+                            )
+
+        remote.assert_called_once()
+        self.assertEqual(resp.status_code, 200)
+        self.assertEqual(resp.body, b"remote")
+        self.assertEqual(resp.headers.get("X-SNS-Source"), "remote-decrypt")
 
 
 if __name__ == "__main__":