Allow users to subscribe to community chat topics

Dockers/socket-broker/README.md

@@ -19,7 +19,8 @@ Frontend / mobile clients
         │  Socket.IO (connection token + topic token)
         ▼
 Socket broker  ── rooms: user/{uuid}/notifications
-        ▲                 event/{slug}/ticket_statistics
+        ▲                 community/user/{uuid}
+        │                 event/{slug}/ticket_statistics
         │  POST /publish (API key)
 Laravel backend
 ```
@@ -74,7 +75,7 @@ const socket = io("https://bram-sockets.comedykit.be", {
 });
 ```
 
-A user may always subscribe to `user/{their-own-id}/notifications`. Any other topic requires a topic token whose `sub` matches the connection subject and whose `topic` matches the subscription exactly.
+A user may always subscribe to `user/{their-own-id}/notifications` and `community/user/{their-own-id}`. Any other topic requires a topic token whose `sub` matches the connection subject and whose `topic` matches the subscription exactly.
 
 ## WebSocket API
 

Dockers/socket-broker/index.js

@@ -172,7 +172,7 @@ function createBroker(env = process.env) {
             return false;
         }
 
-        return /^(user\/[0-9a-fA-F-]{36}\/notifications|event\/[A-Za-z0-9_-]+\/ticket_statistics)$/.test(topic);
+        return /^(user\/[0-9a-fA-F-]{36}\/notifications|community\/user\/[0-9a-fA-F-]{36}|event\/[A-Za-z0-9_-]+\/ticket_statistics)$/.test(topic);
     }
 
     function normalizeSubscription(payload) {
@@ -205,6 +205,12 @@ function createBroker(env = process.env) {
             return userTopic[1] === socket.data.auth.sub;
         }
 
+        const communityUserTopic = topic.match(/^community\/user\/([^/]+)$/);
+
+        if (communityUserTopic) {
+            return communityUserTopic[1] === socket.data.auth.sub;
+        }
+
         const verifiedTopicToken = verifyToken(topicToken, 'topic');
 
         if (!verifiedTopicToken) {

Dockers/socket-broker/test/socket-broker.test.js

@@ -203,6 +203,37 @@ test('socket broker', async t => {
             socket.close();
         });
 
+        await t.test('a user can subscribe to their own community topic only', async () => {
+            const userId = randomUuid();
+            const otherUserId = randomUuid();
+            const socket = connect({ token: connectToken(userId) });
+
+            await once(socket, 'connect');
+
+            socket.emit('subscribe', `community/user/${userId}`);
+            const subscribed = await once(socket, 'subscribed');
+            assert.equal(subscribed.topic, `community/user/${userId}`);
+
+            socket.emit('subscribe', `community/user/${otherUserId}`);
+            const error = await once(socket, 'error');
+            assert.equal(error.code, 'FORBIDDEN_TOPIC');
+
+            socket.close();
+        });
+
+        await t.test('invalid community topics are rejected', async () => {
+            const userId = randomUuid();
+            const socket = connect({ token: connectToken(userId) });
+
+            await once(socket, 'connect');
+
+            socket.emit('subscribe', 'community/user/not-a-uuid');
+            const error = await once(socket, 'error');
+            assert.equal(error.code, 'INVALID_TOPIC');
+
+            socket.close();
+        });
+
         await t.test('event stats require a matching topic token', async () => {
             const userId = randomUuid();
             const eventTopic = 'event/test-event/ticket_statistics';