fix(users): trace google oauth redirect mismatches

apps/users/services/google_oauth.py

@@ -1,10 +1,10 @@
 from __future__ import annotations
 
+import logging
 import secrets
 from dataclasses import asdict, dataclass, is_dataclass
 from typing import Any
-from urllib.parse import urlencode
-from urllib.parse import urlparse
+from urllib.parse import urlencode, urlparse
 
 import requests
 from django.conf import settings
@@ -16,7 +16,6 @@ from apps.users.email_identity import mask_mobile, normalize_email_identity
 from apps.users.models import User, UserSocialAccount
 from apps.users.services.auth import generate_and_send_otp, get_tokens_for_user
 
-
 GOOGLE_AUTH_URL = "https://accounts.google.com/o/oauth2/v2/auth"
 GOOGLE_TOKEN_URL = "https://oauth2.googleapis.com/token"
 GOOGLE_USERINFO_URL = "https://openidconnect.googleapis.com/v1/userinfo"
@@ -27,6 +26,8 @@ GOOGLE_FLOW_TTL_SECONDS = 900
 GOOGLE_STATE_CACHE_PREFIX = "google_oauth_state"
 GOOGLE_FLOW_CACHE_PREFIX = "google_oauth_flow"
 
+logger = logging.getLogger(__name__)
+
 
 class GoogleOAuthFlowError(APIException):
     status_code = 409
@@ -305,6 +306,16 @@ def exchange_code_for_google_profile(code: str) -> GoogleProfile:
         token_response.raise_for_status()
         token_payload = token_response.json()
     except requests.RequestException as exc:
+        response = getattr(exc, "response", None)
+        logger.warning(
+            "Google token exchange failed",
+            extra={
+                "google_status_code": getattr(response, "status_code", None),
+                "google_response_text": getattr(response, "text", "")[:1000] if response is not None else "",
+                "google_redirect_uri": getattr(settings, "GOOGLE_OAUTH_REDIRECT_URI", ""),
+            },
+            exc_info=True,
+        )
         raise ValidationError({"detail": "Google token exchange failed."}) from exc
 
     access_token = token_payload.get("access_token")
@@ -320,6 +331,15 @@ def exchange_code_for_google_profile(code: str) -> GoogleProfile:
         userinfo_response.raise_for_status()
         userinfo = userinfo_response.json()
     except requests.RequestException as exc:
+        response = getattr(exc, "response", None)
+        logger.warning(
+            "Google user profile lookup failed",
+            extra={
+                "google_status_code": getattr(response, "status_code", None),
+                "google_response_text": getattr(response, "text", "")[:1000] if response is not None else "",
+            },
+            exc_info=True,
+        )
         raise ValidationError({"detail": "Google user profile lookup failed."}) from exc
 
     provider_user_id = userinfo.get("sub", "")
@@ -431,7 +451,10 @@ def complete_google_signup(flow: str, mobile: str) -> dict[str, Any]:
             user=existing_mobile_user,
             mobile=normalized_mobile,
             resolution="existing_mobile_claim",
-            detail="Existing mobile account found. Verify ownership to attach Google and set the verified email address.",
+            detail=(
+                "Existing mobile account found. Verify ownership to attach "
+                "Google and set the verified email address."
+            ),
         )
         update_google_flow(flow, claim_payload)
         return _build_public_google_flow_payload(claim_payload)

apps/users/tests/test_api_views.py

@@ -1,18 +1,22 @@
 from io import StringIO
 from unittest.mock import Mock, patch
+from urllib.parse import parse_qs, urlparse
 
 from django.conf import settings
 from django.core.cache import cache
 from django.core.management import call_command
 from django.db import IntegrityError
 from django.test import override_settings
-from rest_framework.test import APIRequestFactory
 from rest_framework import status
-from rest_framework.test import APITestCase
+from rest_framework.test import APIRequestFactory, APITestCase
 
 from apps.users.api.views import RegisterWithPasswordView
 from apps.users.models import User, UserSocialAccount
-from apps.users.services.google_oauth import GoogleProfile
+from apps.users.services.google_oauth import (
+    GoogleProfile,
+    build_google_authorization_url,
+    exchange_code_for_google_profile,
+)
 
 
 class UserApiViewTests(APITestCase):
@@ -551,6 +555,42 @@ class GoogleOAuthApiTests(APITestCase):
         self.assertIn("accounts.google.com", response["Location"])
         self.assertIn("state=", response["Location"])
 
+    @patch("apps.users.services.google_oauth.requests.get")
+    @patch("apps.users.services.google_oauth.requests.post")
+    def test_google_token_exchange_uses_the_same_configured_redirect_uri_as_authorization_url(
+        self,
+        requests_post,
+        requests_get,
+    ):
+        auth_url = build_google_authorization_url()
+        parsed_auth_url = urlparse(auth_url)
+        auth_redirect_uri = parse_qs(parsed_auth_url.query)["redirect_uri"][0]
+
+        token_response = Mock()
+        token_response.raise_for_status.return_value = None
+        token_response.json.return_value = {"access_token": "google-access-token"}
+        requests_post.return_value = token_response
+
+        userinfo_response = Mock()
+        userinfo_response.raise_for_status.return_value = None
+        userinfo_response.json.return_value = {
+            "sub": "google-sub-redirect-uri",
+            "email": "redirect@example.com",
+            "email_verified": True,
+            "given_name": "Redirect",
+            "family_name": "Uri",
+            "picture": "https://example.com/avatar.png",
+        }
+        requests_get.return_value = userinfo_response
+
+        exchange_code_for_google_profile("google-auth-code")
+
+        self.assertEqual(
+            requests_post.call_args.kwargs["data"]["redirect_uri"],
+            auth_redirect_uri,
+        )
+        self.assertEqual(auth_redirect_uri, settings.GOOGLE_OAUTH_REDIRECT_URI)
+
     @patch("apps.users.services.google_oauth.requests.get")
     @patch("apps.users.api.views.exchange_code_for_google_profile")
     def test_google_callback_redirects_with_authenticated_flow_for_linked_account(
@@ -995,7 +1035,7 @@ class GoogleOAuthAuditCommandTests(APITestCase):
             password="secret123",
             email="owner@example.com",
         )
-        other_user = User.objects.create_user(
+        User.objects.create_user(
             mobile="09126660002",
             password="secret123",
             email="shared@example.com",