Exclude functional members from DM detection (#9124)

* Exclude functional members from DM detection

* Fix getRoomFunctionalMembers test

* Simplify getFunctionalMembers

* Remove unnecessary filter

src/utils/room/getFunctionalMembers.ts

@@ -0,0 +1,27 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { Room, UNSTABLE_ELEMENT_FUNCTIONAL_USERS } from "matrix-js-sdk/src/matrix";
+
+export const getFunctionalMembers = (room: Room): string[] => {
+    const [functionalUsersStateEvent] = room.currentState.getStateEvents(UNSTABLE_ELEMENT_FUNCTIONAL_USERS.name);
+
+    if (Array.isArray(functionalUsersStateEvent?.getContent().service_members)) {
+        return functionalUsersStateEvent.getContent().service_members;
+    }
+
+    return [];
+};

src/utils/room/getJoinedNonFunctionalMembers.ts

@@ -0,0 +1,27 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { Room, RoomMember } from "matrix-js-sdk/src/matrix";
+
+import { getFunctionalMembers } from "./getFunctionalMembers";
+
+/**
+ * Returns all room members that are non-functional (bots etc.).
+ */
+export const getJoinedNonFunctionalMembers = (room: Room): RoomMember[] => {
+    const functionalMembers = getFunctionalMembers(room);
+    return room.getJoinedMembers().filter(m => !functionalMembers.includes(m.userId));
+};