From 8a48eb3f947cf2dc5154610ace59df2db85d2ff3 Mon Sep 17 00:00:00 2001
From: Mykola Mokhnach <nick+1@wire.com>
Date: Fri, 23 Mar 2018 18:44:33 +0100
Subject: [PATCH] Tune prefix handling for web socket pathnames (#198)

---
 index.js                                |  4 ++++
 lib/express/websocket.js                | 15 ++++++++-------
 test/basedriver/websockets-e2e-specs.js | 11 ++++++-----
 3 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/index.js b/index.js
index 477be51c5..d8578aa89 100644
--- a/index.js
+++ b/index.js
@@ -34,3 +34,7 @@ export { statusCodes, getSummaryByCode };
 // W3C capabilities parser
 import { processCapabilities } from './lib/basedriver/capabilities';
 export { processCapabilities };
+
+// Web socket helpers
+import { DEFAULT_WS_PATHNAME_PREFIX } from './lib/express/websocket';
+export { DEFAULT_WS_PATHNAME_PREFIX };
diff --git a/lib/express/websocket.js b/lib/express/websocket.js
index a3fe8998d..25f964c96 100644
--- a/lib/express/websocket.js
+++ b/lib/express/websocket.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import url from 'url';
 
-const PATHNAME_PREFIX = '/ws';
+const DEFAULT_WS_PATHNAME_PREFIX = '/ws';
 
 
 /**
@@ -11,14 +11,13 @@ const PATHNAME_PREFIX = '/ws';
  *
  * @param {Object} server - An instance of express HTTP server.
  * @param {string} handlerPathname - Web socket endpoint path starting with
- * single slash charcter. `/wd/ws` prefix is automatically added to the
- * actual endpoint.
+ * a single slash character. It is recommended to always add
+ * DEFAULT_WS_PATHNAME_PREFIX to all web socket pathnames.
  * @param {Object} handlerServer - WebSocket server instance. See
  * https://github.com/websockets/ws/pull/885 for more details
  * on how to configure the handler properly.
- * @param {?string} pathnamePrefix ['/ws'] - Pathname prefix.
  */
-async function addWebSocketHandler (handlerPathname, handlerServer, pathnamePrefix = PATHNAME_PREFIX) {
+async function addWebSocketHandler (handlerPathname, handlerServer) {
   let isUpgradeListenerAssigned = true;
   if (_.isUndefined(this.webSocketsMapping)) {
     this.webSocketsMapping = {};
@@ -33,7 +32,7 @@ async function addWebSocketHandler (handlerPathname, handlerServer, pathnamePref
   this.on('upgrade', (request, socket, head) => {
     const currentPathname = url.parse(request.url).pathname;
     for (const [pathname, wsServer] of _.toPairs(this.webSocketsMapping)) {
-      if (currentPathname === (_.isEmpty(pathnamePrefix) ? pathname : `${pathnamePrefix}${pathname}`)) {
+      if (currentPathname === pathname) {
         wsServer.handleUpgrade(request, socket, head, (ws) => {
           wsServer.emit('connection', ws);
         });
@@ -114,4 +113,6 @@ async function removeAllWebSocketHandlers () {
   return result;
 }
 
-export { addWebSocketHandler, removeWebSocketHandler, removeAllWebSocketHandlers, getWebSocketHandlers };
+export { addWebSocketHandler, removeWebSocketHandler,
+         removeAllWebSocketHandlers, getWebSocketHandlers,
+         DEFAULT_WS_PATHNAME_PREFIX };
diff --git a/test/basedriver/websockets-e2e-specs.js b/test/basedriver/websockets-e2e-specs.js
index 1f51c33ec..cefe5697e 100644
--- a/test/basedriver/websockets-e2e-specs.js
+++ b/test/basedriver/websockets-e2e-specs.js
@@ -1,5 +1,6 @@
 import _ from 'lodash';
-import { server, routeConfiguringFunction} from '../..';
+import { server, routeConfiguringFunction,
+         DEFAULT_WS_PATHNAME_PREFIX } from '../..';
 import { FakeDriver } from '../protocol/fake-driver';
 import chai from 'chai';
 import chaiAsPromised from 'chai-as-promised';
@@ -35,13 +36,13 @@ describe('Websockets (e2e)', function () {
         }
       });
       const previousListenerCount = baseServer.listenerCount('upgrade');
-      const endpoint = '/hello';
-      const timeout  = 5000;
+      const endpoint = `${DEFAULT_WS_PATHNAME_PREFIX}/hello`;
+      const timeout = 5000;
       await baseServer.addWebSocketHandler(endpoint, wss);
       baseServer.listenerCount('upgrade').should.be.above(previousListenerCount);
       _.keys(await baseServer.getWebSocketHandlers()).length.should.eql(1);
       await new B((resolve, reject) => {
-        const client = new WebSocket(`ws://localhost:${PORT}/ws${endpoint}`);
+        const client = new WebSocket(`ws://localhost:${PORT}${endpoint}`);
         client.on('message', (data) => {
           data.should.eql(WS_DATA);
           resolve();
@@ -54,7 +55,7 @@ describe('Websockets (e2e)', function () {
       (await baseServer.removeWebSocketHandler(endpoint)).should.be.true;
       _.keys(await baseServer.getWebSocketHandlers()).length.should.eql(0);
       await new B((resolve, reject) => {
-        const client = new WebSocket(`ws://localhost:${PORT}/ws${endpoint}`);
+        const client = new WebSocket(`ws://localhost:${PORT}${endpoint}`);
         client.on('message', (data) =>
           reject(new Error(`No websocket messages are expected after the handler ` +
                            `has been removed. '${data}' is received instead. `))