Suggestions for refactoring

graph/context.js

@@ -53,7 +53,7 @@ class Context {
     this.plugins = decorateContextPlugins(this, contextPlugins);
 
     // Bind the publish/subscribe to the context.
-    this.pubsub = pubsub();
+    this.pubsub = pubsub.createClient();
   }
 }
 

graph/subscriptions.js

@@ -133,7 +133,7 @@ const setupFunctions = plugins.get('server', 'setupFunctions').reduce((acc, {plu
 const createSubscriptionManager = (server) => new SubscriptionServer({
   subscriptionManager: new SubscriptionManager({
     schema,
-    pubsub: pubsub(),
+    pubsub: pubsub.createClient(),
     setupFunctions,
   }),
   onConnect: ({token}, connection) => {

services/kue.js

@@ -8,7 +8,7 @@ const kue = module.exports.kue = require('kue');
 // Note that unlike what the name createQueue suggests, it currently returns a
 // singleton Queue instance. So you can configure and use only a single Queue
 // object within your node.js process.
-let Queue = module.exports.queue;
+let Queue = module.exports.queue = null;
 
 class Task {
 
@@ -22,7 +22,7 @@ class Task {
     if (!Queue) {
       module.exports.queue = Queue = kue.createQueue({
         redis: {
-          createClientFactory: () => redis.createClient()
+          createClientFactory: redis.createClientFactory()
         }
       });
     }

services/mailer.js

@@ -69,6 +69,7 @@ if (SMTP_PORT) {
 }
 
 const defaultTransporter = nodemailer.createTransport(options);
+let taskInstance = null;
 
 const mailer = module.exports = {
 
@@ -77,15 +78,15 @@ const mailer = module.exports = {
    */
   _task: null,
   get task() {
-    if (mailer._task) {
-      return mailer._task;
+    if (taskInstance) {
+      return taskInstance;
     }
 
-    mailer._task = new kue.Task({
+    taskInstance = new kue.Task({
       name: 'mailer'
     });
 
-    return mailer._task;
+    return taskInstance;
   },
 
   sendSimple({template, locals, to, subject}) {

services/passport.js

@@ -13,17 +13,7 @@ const bowser = require('bowser');
 const ms = require('ms');
 
 // Create a redis client to use for authentication.
-const {createClient} = require('./redis');
-let _client = null;
-const getClient = () => {
-  if (_client) {
-    return _client;
-  }
-
-  _client = createClient();
-
-  return _client;
-};
+const {createClientFactory} = require('./redis');
 
 const {
   JWT_SECRET,
@@ -157,7 +147,7 @@ const HandleLogout = (req, res, next) => {
   const now = new Date();
   const expiry = (jwt.exp - now.getTime() / 1000).toFixed(0);
 
-  getClient().set(`jtir[${jwt.jti}]`, now.toISOString(), 'EX', expiry, (err) => {
+  createClientFactory().set(`jtir[${jwt.jti}]`, now.toISOString(), 'EX', expiry, (err) => {
     if (err) {
       return next(err);
     }
@@ -168,7 +158,7 @@ const HandleLogout = (req, res, next) => {
 };
 
 const checkGeneralTokenBlacklist = (jwt) => new Promise((resolve, reject) => {
-  getClient().get(`jtir[${jwt.jti}]`, (err, expiry) => {
+  createClientFactory().get(`jtir[${jwt.jti}]`, (err, expiry) => {
     if (err) {
       return reject(err);
     }

services/pubsub.js

@@ -2,13 +2,15 @@ const {RedisPubSub} = require('graphql-redis-subscriptions');
 
 const {connectionOptions} = require('./redis');
 
-let pubsub = null;
-module.exports = () => {
-  if (pubsub) {
-    return pubsub;
+let pubsubInstance = null;
+module.exports = {
+  createClient: () => {
+    if (pubsubInstance) {
+      return pubsubInstance;
+    }
+
+    pubsubInstance = new RedisPubSub({connection: connectionOptions});
+
+    return pubsubInstance;
   }
-
-  pubsub = new RedisPubSub({connection: connectionOptions});
-
-  return pubsub;
 };

services/redis.js

@@ -29,21 +29,36 @@ const connectionOptions = {
   }
 };
 
+const createClient = () => {
+  let client = redis.createClient(connectionOptions);
+
+  client.ping((err) => {
+    if (err) {
+      console.error('Can\'t ping the redis server!');
+
+      throw err;
+    }
+
+    debug('connection established');
+  });
+
+  return client;
+};
+
 module.exports = {
   connectionOptions,
-  createClient() {
-    let client = redis.createClient(connectionOptions);
+  createClient,
+  createClientFactory: () => {
+    let client = null;
 
-    client.ping((err) => {
-      if (err) {
-        console.error('Can\'t ping the redis server!');
-
-        throw err;
+    return () => {
+      if (client) {
+        return client;
       }
 
-      debug('connection established');
-    });
+      client = createClient();
 
-    return client;
+      return client;
+    };
   }
 };

services/scraper.js

@@ -5,6 +5,8 @@ const AssetsService = require('./assets');
 
 const metascraper = require('metascraper');
 
+let taskInstance = null;
+
 /**
  * Exposes a service object to allow operations to execute against the scraper.
  * @type {Object}
@@ -14,17 +16,16 @@ const scraper = {
   /**
    * Create the new Task kue singleton.
    */
-  _task: null,
   get task() {
-    if (scraper._task) {
-      return scraper._task;
+    if (taskInstance) {
+      return taskInstance;
     }
 
-    scraper._task = new kue.Task({
+    taskInstance = new kue.Task({
       name: 'scraper'
     });
 
-    return scraper._task;
+    return taskInstance;
   },
 
   /**

services/users.js

@@ -30,17 +30,7 @@ const PASSWORD_RESET_JWT_SUBJECT = 'password_reset';
 const SALT_ROUNDS = 10;
 
 // Create a redis client to use for authentication.
-const {createClient} = require('./redis');
-let _client = null;
-const getClient = () => {
-  if (_client) {
-    return _client;
-  }
-
-  _client = createClient();
-
-  return _client;
-};
+const {createClientFactory} = require('./redis');
 
 // UsersService is the interface for the application to interact with the
 // UserModel through.
@@ -77,7 +67,7 @@ module.exports = class UsersService {
     const rdskey = `la[${email.toLowerCase().trim()}]`;
 
     return new Promise((resolve, reject) => {
-      getClient()
+      createClientFactory()
         .multi()
         .incr(rdskey)
         .expire(rdskey, RECAPTCHA_WINDOW_SECONDS)
@@ -90,7 +80,7 @@ module.exports = class UsersService {
           if (replies[0] === 1 || replies[1] === -1) {
 
             // then expire it after the timeout
-            getClient().expire(rdskey, RECAPTCHA_WINDOW_SECONDS);
+            createClientFactory().expire(rdskey, RECAPTCHA_WINDOW_SECONDS);
           }
 
           if (replies[0] >= RECAPTCHA_INCORRECT_TRIGGER) {
@@ -112,7 +102,7 @@ module.exports = class UsersService {
     const rdskey = `la[${email.toLowerCase().trim()}]`;
 
     return new Promise((resolve, reject) => {
-      getClient()
+      createClientFactory()
         .get(rdskey, (err, reply) => {
           if (err) {
             return reject(err);