forward requester id to check username for spam callbacks

changelog.d/17916.feature

@@ -0,0 +1 @@
+Module developers will have access to user id of requester when adding `check_username_for_spam` callbacks to `spam_checker_module_callbacks`.

synapse/handlers/user_directory.py

@@ -161,7 +161,7 @@ async def search_users(
         non_spammy_users = []
         for user in results["results"]:
             if not await self._spam_checker_module_callbacks.check_username_for_spam(
-                user
+                user, user_id
             ):
                 non_spammy_users.append(user)
         results["results"] = non_spammy_users

synapse/module_api/callbacks/spamchecker_callbacks.py

@@ -168,7 +168,7 @@
         ]
     ],
 ]
-CHECK_USERNAME_FOR_SPAM_CALLBACK = Callable[[UserProfile], Awaitable[bool]]
+CHECK_USERNAME_FOR_SPAM_CALLBACK = Callable[[UserProfile, str], Awaitable[bool]]
 LEGACY_CHECK_REGISTRATION_FOR_SPAM_CALLBACK = Callable[
     [
         Optional[dict],
@@ -716,7 +716,9 @@ async def user_may_publish_room(
 
         return self.NOT_SPAM
 
-    async def check_username_for_spam(self, user_profile: UserProfile) -> bool:
+    async def check_username_for_spam(
+        self, user_profile: UserProfile, requester_id: str
+    ) -> bool:
         """Checks if a user ID or display name are considered "spammy" by this server.
 
         If the server considers a username spammy, then it will not be included in
@@ -727,6 +729,7 @@ async def check_username_for_spam(self, user_profile: UserProfile) -> bool:
                 * user_id
                 * display_name
                 * avatar_url
+            requester_id: The user ID of the user making the user directory search request.
 
         Returns:
             True if the user is spammy.
@@ -735,7 +738,9 @@ async def check_username_for_spam(self, user_profile: UserProfile) -> bool:
             with Measure(self.clock, f"{callback.__module__}.{callback.__qualname__}"):
                 # Make a copy of the user profile object to ensure the spam checker cannot
                 # modify it.
-                res = await delay_cancellation(callback(user_profile.copy()))
+                res = await delay_cancellation(
+                    callback(user_profile.copy(), requester_id)
+                )
             if res:
                 return True
 

tests/handlers/test_user_directory.py

@@ -796,7 +796,7 @@ def test_spam_checker(self) -> None:
         s = self.get_success(self.handler.search_users(u1, "user2", 10))
         self.assertEqual(len(s["results"]), 1)
 
-        async def allow_all(user_profile: UserProfile) -> bool:
+        async def allow_all(user_profile: UserProfile, requester_id: str) -> bool:
             # Allow all users.
             return False
 
@@ -810,7 +810,7 @@ async def allow_all(user_profile: UserProfile) -> bool:
         self.assertEqual(len(s["results"]), 1)
 
         # Configure a spam checker that filters all users.
-        async def block_all(user_profile: UserProfile) -> bool:
+        async def block_all(user_profile: UserProfile, requester_id: str) -> bool:
             # All users are spammy.
             return True