fix: RefreshError시 로그인 요청 응답 추가

backend/app/auth/dependencies.py

@@ -6,6 +6,7 @@
 import logging
 
 from fastapi import Depends, HTTPException
+from google.auth.exceptions import RefreshError
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.auth.service import build_credentials
@@ -40,13 +41,16 @@ async def get_google_user(
             await asyncio.to_thread(credentials.refresh, Request())
             user.google_oauth_token = encrypt_value(credentials.token)
             await db.commit()
-        except Exception as exc:
+        except RefreshError as exc:
             logger.warning(f"Google 토큰 갱신 실패 (user={user.id}): {exc}")
             raise HTTPException(
                 status_code=401,
                 detail={
                     "code": "token_expired",
-                    "message": "Google 토큰이 만료되었습니다. 다시 로그인해주세요.",
+                    "message": (
+                        "Google 인증 정보가 만료되었거나 취소되었습니다. "
+                        "다시 로그인해야 합니다."
+                    ),
                 },
             ) from exc
 

backend/pyproject.toml

@@ -7,6 +7,7 @@ requires-python = ">=3.13"
 dependencies = [
     "fastapi[standard]",
     "sqlalchemy",
+    "greenlet",
     "aiosqlite",
     "python-dotenv",
     "httpx",

backend/tests/test_auth_dependencies.py

@@ -0,0 +1,49 @@
+from __future__ import annotations
+
+from types import SimpleNamespace
+
+import pytest
+from fastapi import HTTPException
+from google.auth.exceptions import RefreshError
+
+from app.auth.dependencies import get_google_user
+
+
+class _FailingCredentials:
+    expired = True
+    refresh_token = "refresh-token"
+    token = "stale-token"
+
+    def refresh(self, _request) -> None:
+        raise RefreshError("refresh token revoked")
+
+
+class _UnusedDbSession:
+    async def commit(self) -> None:
+        raise AssertionError("commit should not run when refresh fails")
+
+
+@pytest.mark.asyncio
+async def test_get_google_user_returns_401_on_refresh_error(monkeypatch):
+    user = SimpleNamespace(
+        id=123,
+        google_oauth_token="encrypted-token",
+        google_refresh_token="encrypted-refresh-token",
+    )
+
+    async def fake_to_thread(func, *args, **kwargs):
+        return func(*args, **kwargs)
+
+    monkeypatch.setattr("app.auth.dependencies.decrypt_value", lambda value: value)
+    monkeypatch.setattr(
+        "app.auth.dependencies.build_credentials",
+        lambda token, refresh_token: _FailingCredentials(),
+    )
+    monkeypatch.setattr("app.auth.dependencies.asyncio.to_thread", fake_to_thread)
+
+    with pytest.raises(HTTPException) as exc_info:
+        await get_google_user(user=user, db=_UnusedDbSession())
+
+    assert exc_info.value.status_code == 401
+    assert exc_info.value.detail["code"] == "token_expired"
+    assert "다시 로그인" in exc_info.value.detail["message"]