施工(HEL-226): 实现登录门户与本机免密切换账号

用设备 Cookie 和授权表记住本机已验证账号，登录页按确认样图做成门户，不再把密码写进浏览器。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

tests/test_account_switch_grants.py

@@ -0,0 +1,132 @@
+from __future__ import annotations
+
+import threading
+import unittest
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+from backend.features.accounts.security import SecretVault, token_hash
+from backend.features.accounts.service import AccountService
+from database import ReviewDatabase
+
+
+class AccountSwitchGrantTests(unittest.TestCase):
+    def setUp(self) -> None:
+        self.temp = TemporaryDirectory()
+        self.database = ReviewDatabase(Path(self.temp.name) / "review.db")
+        self.bound_user_id = 0
+        self.service = AccountService(
+            database=self.database,
+            vault=SecretVault(SecretVault.generate_key()),
+            current_user_supplier=lambda: self.bound_user_id,
+            access_supplier=lambda: self.database.user_access(self.bound_user_id) or {},
+            bind_user=self._bind,
+            personal_field_builder=lambda *args, **kwargs: {},
+            auth_lock=threading.Lock(),
+        )
+        self.device_a = token_hash("device-a-token")
+        self.device_b = token_hash("device-b-token")
+
+    def tearDown(self) -> None:
+        self.temp.cleanup()
+
+    def _bind(self, user_id: int) -> None:
+        self.bound_user_id = int(user_id)
+
+    def _register(self, username: str, device_hash: str = "") -> dict:
+        return self.service.register(username, "Password123", device_hash or self.device_a)
+
+    def test_login_records_accounts_for_the_current_device_only(self) -> None:
+        first = self._register("alpha_user")
+        second = self._register("beta_user")
+        self.service.login("alpha_user", "Password123", self.device_b)
+
+        listed = self.service.list_device_accounts(self.device_a)
+        names = [item["username"] for item in listed["accounts"]]
+        self.assertEqual(names, ["beta_user", "alpha_user"])
+        self.assertEqual(
+            self.service.list_device_accounts(self.device_b)["accounts"][0]["username"],
+            "alpha_user",
+        )
+        self.assertEqual(self.service.list_device_accounts("")["accounts"], [])
+        self.assertEqual(first["user"]["username"], "alpha_user")
+        self.assertEqual(second["user"]["username"], "beta_user")
+
+    def test_switch_uses_device_grant_and_keeps_the_original_authorization(self) -> None:
+        first = self._register("alpha_user")
+        self._register("beta_user")
+        switched = self.service.switch_account(self.device_a, int(first["user"]["id"]))
+        self.assertEqual(switched["user"]["username"], "alpha_user")
+        remaining = {
+            item["username"]
+            for item in self.service.list_device_accounts(self.device_a)["accounts"]
+        }
+        self.assertEqual(remaining, {"alpha_user", "beta_user"})
+
+    def test_switch_without_a_valid_grant_requires_reauthentication(self) -> None:
+        user = self._register("alpha_user")
+        with self.assertRaisesRegex(PermissionError, "该账号需重新验证"):
+            self.service.switch_account(self.device_b, int(user["user"]["id"]))
+        with self.assertRaisesRegex(PermissionError, "该账号需重新验证"):
+            self.service.switch_account("", int(user["user"]["id"]))
+
+    def test_forget_only_removes_the_current_device_grant(self) -> None:
+        user = self._register("alpha_user")
+        self.service.login("alpha_user", "Password123", self.device_b)
+        self.service.forget_account(self.device_a, int(user["user"]["id"]))
+        self.service.forget_account(self.device_a, int(user["user"]["id"]))
+        self.assertEqual(self.service.list_device_accounts(self.device_a)["accounts"], [])
+        self.assertEqual(
+            self.service.list_device_accounts(self.device_b)["accounts"][0]["username"],
+            "alpha_user",
+        )
+
+    def test_logout_revokes_only_the_current_account_on_this_device(self) -> None:
+        first = self._register("alpha_user")
+        second = self._register("beta_user")
+        self.service.revoke_current_device_grant(self.device_a, int(second["user"]["id"]))
+        names = {
+            item["username"]
+            for item in self.service.list_device_accounts(self.device_a)["accounts"]
+        }
+        self.assertEqual(names, {"alpha_user"})
+        switched = self.service.switch_account(self.device_a, int(first["user"]["id"]))
+        self.assertEqual(switched["user"]["id"], first["user"]["id"])
+
+    def test_password_change_revokes_grants_on_every_device(self) -> None:
+        user = self._register("alpha_user")
+        self.service.login("alpha_user", "Password123", self.device_b)
+        self._bind(int(user["user"]["id"]))
+        self.service.change_password("Password123", "Password456")
+        self.assertEqual(self.service.list_device_accounts(self.device_a)["accounts"], [])
+        self.assertEqual(self.service.list_device_accounts(self.device_b)["accounts"], [])
+        with self.assertRaisesRegex(PermissionError, "该账号需重新验证"):
+            self.service.switch_account(self.device_a, int(user["user"]["id"]))
+
+    def test_device_keeps_at_most_five_accounts(self) -> None:
+        usernames = [f"user_{index}" for index in range(6)]
+        ids = [self._register(name)["user"]["id"] for name in usernames]
+        listed = self.service.list_device_accounts(self.device_a)["accounts"]
+        self.assertEqual(len(listed), 5)
+        kept = {item["user_id"] for item in listed}
+        self.assertNotIn(ids[0], kept)
+        self.assertTrue(set(ids[1:]).issubset(kept))
+
+    def test_expired_grants_are_removed_lazily(self) -> None:
+        user = self._register("alpha_user")
+        past = (datetime.now(timezone.utc) - timedelta(days=1)).isoformat(timespec="seconds")
+        self.database.upsert_switch_grant(
+            self.device_a,
+            int(user["user"]["id"]),
+            past,
+            past,
+            past,
+        )
+        self.assertEqual(self.service.list_device_accounts(self.device_a)["accounts"], [])
+        with self.assertRaisesRegex(PermissionError, "该账号需重新验证"):
+            self.service.switch_account(self.device_a, int(user["user"]["id"]))
+
+
+if __name__ == "__main__":
+    unittest.main()