Add the ability to filter by state event type on admin room state endpoint

changelog.d/18035.feature

@@ -1,2 +1,2 @@
-Adds a query param `type` to `/_synapse/admin/v1/rooms/{room_id}/state` that filters the state event
-query by state event type.
+Add a query param `type` to the [Room State Admin API](https://element-hq.github.io/synapse/develop/admin_api/rooms.html#room-state-api)
+that filters the state event.

docs/admin_api/rooms.md

@@ -390,7 +390,7 @@ GET /_synapse/admin/v1/rooms/<room_id>/state
 The following query parameter is available:
 
 * `type` - The type of room state event to filter by, eg "m.room.create". If provided, only state events
-    of this type will be returned. 
+    of this type will be returned (regardless of their `state_key` value).
 
 A response body like the following is returned:
 

synapse/rest/admin/rooms.py

@@ -468,11 +468,6 @@ async def on_GET(
         type = parse_string(request, "type")
 
         if type:
-            if not type.startswith("m.room."):
-                raise SynapseError(
-                    HTTPStatus.BAD_REQUEST,
-                    "Type must be a room state event.",
-                )
             state_filter = StateFilter(
                 types=immutabledict({type: None}),
                 include_others=False,

tests/rest/admin/test_room.py

@@ -2052,16 +2052,34 @@ def test_room_state_param(self) -> None:
         self.assertEqual(event["type"], "m.room.member")
         self.assertEqual(event["state_key"], self.admin_user)
 
-    def test_room_state_bad_param(self) -> None:
-        """Test that request with param not conforming to 'm.room.*' will be rejected"""
+    def test_room_state_param_empty(self) -> None:
+        """Test that passing an empty string as state filter param returns no state events"""
         room_id = self.helper.create_room_as(self.admin_user, tok=self.admin_user_tok)
 
         channel = self.make_request(
             "GET",
-            f"/_synapse/admin/v1/rooms/{room_id}/state?type=m.something.else",
+            f"/_synapse/admin/v1/rooms/{room_id}/state?type=''",
             access_token=self.admin_user_tok,
         )
-        self.assertEqual(400, channel.code)
+        self.assertEqual(200, channel.code)
+        state = channel.json_body["state"]
+        self.assertEqual(0, len(state))
+
+    def test_room_state_param_not_in_room(self) -> None:
+        """
+        Test that passing a state filter param for a state event not in the room
+        returns no state events
+        """
+        room_id = self.helper.create_room_as(self.admin_user, tok=self.admin_user_tok)
+
+        channel = self.make_request(
+            "GET",
+            f"/_synapse/admin/v1/rooms/{room_id}/state?type=m.room.custom",
+            access_token=self.admin_user_tok,
+        )
+        self.assertEqual(200, channel.code)
+        state = channel.json_body["state"]
+        self.assertEqual(0, len(state))
 
     def _set_canonical_alias(
         self, room_id: str, test_alias: str, admin_user_tok: str