refactor: promisification

src/server/entry.js

@@ -1,37 +1,27 @@
+/* eslint-disable import/no-extraneous-dependencies */
+import {promisify} from 'util';
+
 import {joinChannel} from '~/common/channel';
 
 import createRedisClient, {keys} from './redis';
 
 const redisClient = createRedisClient();
-
+const mget = promisify(redisClient.mget.bind(redisClient));
 const channelState = async (req, channel) => {
   const messageKeys = await keys(redisClient, `${channel}:messages:*`);
   const messages = 0 === messageKeys.length
     ? []
-    : await new Promise((resolve, reject) => {
-      redisClient.mget(messageKeys, (error, replies) => (
-        error
-          ? reject(error)
-          : resolve(replies
+    : (await mget(messageKeys))
       .map((reply, i) => ({
         ...JSON.parse(reply),
         uuid: messageKeys[i].split(':')[2],
       }))
-            .sort((l, r) => l.timestamp - r.timestamp))
-      ));
-    });
+      .sort((l, r) => l.timestamp - r.timestamp);
   const socketKeys = await keys(redisClient, `${channel}:users:*`);
   const users = 0 === socketKeys.length
     ? []
-    : await new Promise((resolve, reject) => {
-      redisClient.mget(socketKeys, (error, replies) => (
-        error ? reject(error) : resolve(
-          Object
-            .keys(replies.reduce((r, k) => ({[k]: true, ...r}), {}))
-            .map((idStrings) => parseInt(idStrings, 10)),
-        )
-      ));
-    });
+    : Object.keys((await mget(socketKeys)).reduce((r, k) => ({[k]: true, ...r}), {}))
+      .map((idStrings) => parseInt(idStrings, 10));
   return {
     messages,
     users,

src/server/sockets.js

@@ -1,4 +1,6 @@
 /* eslint-disable import/no-extraneous-dependencies */
+import {promisify} from 'util';
+
 import redisAdapter from 'socket.io-redis';
 import {v4 as uuidv4} from 'uuid';
 
@@ -17,6 +19,7 @@ import session from './session';
 const pubClient = createRedisClient();
 const subClient = createRedisClient();
 const adapter = redisAdapter({pubClient, subClient});
+const set = promisify(pubClient.set.bind(pubClient));
 
 export function createSocketServer(httpServer) {
   const socketServer = new SocketServer(httpServer, {
@@ -35,25 +38,15 @@ export function createSocketServer(httpServer) {
     next();
   });
   socketServer.io.use(async (socket, next) => {
+    const join = promisify(socket.join.bind(socket));
     await Promise.all(
       channelsToHydrate(socket.handshake)
-        .map((channel) => new Promise((resolve, reject) => {
-          socket.join(
-            joinChannel(channel),
-            (error) => (error ? reject(error) : resolve()),
-          );
-        })),
-    );
-    next();
-  });
-  socketServer.io.use(async (socket, next) => {
-    await Promise.all(
-      channelsToHydrate(socket.handshake)
-        .map((channel) => new Promise((resolve, reject) => {
-          const key = `${joinChannel(channel)}:users:${socket.id}`;
+        .map(async (channel) => {
+          const channelString = joinChannel(channel);
+          await join(channelString);
           const {user} = socket.handshake;
-          pubClient.set(key, user ? user.id : 0, (error) => (error ? reject(error) : resolve()));
-        })),
+          await set(`${channelString}:users:${socket.id}`, user ? user.id : 0);
+        }),
     );
     next();
   });