Step 8.5: Move various room utilities out of createRoom

src/utils/direct-messages.ts

@@ -0,0 +1,46 @@
+/*
+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 { MatrixClient } from "matrix-js-sdk/src/client";
+import { Room } from "matrix-js-sdk/src/models/room";
+
+import DMRoomMap from "./DMRoomMap";
+import { isJoinedOrNearlyJoined } from "./membership";
+
+export function findDMForUser(client: MatrixClient, userId: string): Room {
+    const roomIds = DMRoomMap.shared().getDMRoomsForUserId(userId);
+    const rooms = roomIds.map(id => client.getRoom(id));
+    const suitableDMRooms = rooms.filter(r => {
+        // Validate that we are joined and the other person is also joined. We'll also make sure
+        // that the room also looks like a DM (until we have canonical DMs to tell us). For now,
+        // a DM is a room of two people that contains those two people exactly. This does mean
+        // that bots, assistants, etc will ruin a room's DM-ness, though this is a problem for
+        // canonical DMs to solve.
+        if (r && r.getMyMembership() === "join") {
+            const members = r.currentState.getMembers();
+            const joinedMembers = members.filter(m => isJoinedOrNearlyJoined(m.membership));
+            const otherMember = joinedMembers.find(m => m.userId === userId);
+            return otherMember && joinedMembers.length === 2;
+        }
+        return false;
+    }).sort((r1, r2) => {
+        return r2.getLastActiveTimestamp() -
+            r1.getLastActiveTimestamp();
+    });
+    if (suitableDMRooms.length) {
+        return suitableDMRooms[0];
+    }
+}

src/utils/membership.ts

@@ -15,6 +15,9 @@ limitations under the License.
 */
 
 import { Room } from "matrix-js-sdk/src/models/room";
+import { MatrixClient } from "matrix-js-sdk/src/client";
+import { RoomMember } from "matrix-js-sdk/src/models/room-member";
+import { RoomStateEvent } from "matrix-js-sdk/src/models/room-state";
 
 /**
  * Approximation of a membership status for a given room.
@@ -75,3 +78,27 @@ export function isJoinedOrNearlyJoined(membership: string): boolean {
     const effective = getEffectiveMembership(membership);
     return effective === EffectiveMembership.Join || effective === EffectiveMembership.Invite;
 }
+
+/**
+ * Try to ensure the user is already in the megolm session before continuing
+ * NOTE: this assumes you've just created the room and there's not been an opportunity
+ * for other code to run, so we shouldn't miss RoomState.newMember when it comes by.
+ */
+export async function waitForMember(client: MatrixClient, roomId: string, userId: string, opts = { timeout: 1500 }) {
+    const { timeout } = opts;
+    let handler;
+    return new Promise((resolve) => {
+        handler = function(_, __, member: RoomMember) { // eslint-disable-line @typescript-eslint/naming-convention
+            if (member.userId !== userId) return;
+            if (member.roomId !== roomId) return;
+            resolve(true);
+        };
+        client.on(RoomStateEvent.NewMember, handler);
+
+        /* We don't want to hang if this goes wrong, so we proceed and hope the other
+           user is already in the megolm session */
+        setTimeout(resolve, timeout, false);
+    }).finally(() => {
+        client.removeListener(RoomStateEvent.NewMember, handler);
+    });
+}

src/utils/rooms.ts

@@ -0,0 +1,26 @@
+/*
+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 { getE2EEWellKnown } from "./WellKnownUtils";
+
+export function privateShouldBeEncrypted(): boolean {
+    const e2eeWellKnown = getE2EEWellKnown();
+    if (e2eeWellKnown) {
+        const defaultDisabled = e2eeWellKnown["default"] === false;
+        return !defaultDisabled;
+    }
+    return true;
+}