fix(base-driver): Update the web socket upgrade behavior

packages/base-driver/lib/express/middleware.js

@@ -2,8 +2,16 @@ import _ from 'lodash';
 import log from './logger';
 import {errors} from '../protocol';
 import {handleIdempotency} from './idempotency';
+import {pathToRegexp} from 'path-to-regexp';
 
-function allowCrossDomain(req, res, next) {
+/**
+ *
+ * @param {import('express').Request} req
+ * @param {import('express').Response} res
+ * @param {import('express').NextFunction} next
+ * @returns {any}
+ */
+export function allowCrossDomain(req, res, next) {
   try {
     res.header('Access-Control-Allow-Origin', '*');
     res.header('Access-Control-Allow-Methods', 'GET, POST, PUT, OPTIONS, DELETE');
@@ -22,7 +30,11 @@ function allowCrossDomain(req, res, next) {
   next();
 }
 
-function allowCrossDomainAsyncExecute(basePath) {
+/**
+ * @param {string} basePath
+ * @returns {import('express').RequestHandler}
+ */
+export function allowCrossDomainAsyncExecute(basePath) {
   return (req, res, next) => {
     // there are two paths for async responses, so cover both
     // https://regex101.com/r/txYiEz/1
@@ -36,12 +48,17 @@ function allowCrossDomainAsyncExecute(basePath) {
   };
 }
 
-function fixPythonContentType(basePath) {
+/**
+ *
+ * @param {string} basePath
+ * @returns {import('express').RequestHandler}
+ */
+export function fixPythonContentType(basePath) {
   return (req, res, next) => {
     // hack because python client library gives us wrong content-type
     if (
       new RegExp(`^${_.escapeRegExp(basePath)}`).test(req.path) &&
-      /^Python/.test(req.headers['user-agent'])
+      /^Python/.test(req.headers['user-agent'] ?? '')
     ) {
       if (req.headers['content-type'] === 'application/x-www-form-urlencoded') {
         req.headers['content-type'] = 'application/json; charset=utf-8';
@@ -51,14 +68,55 @@ function fixPythonContentType(basePath) {
   };
 }
 
-function defaultToJSONContentType(req, res, next) {
+/**
+ *
+ * @param {import('express').Request} req
+ * @param {import('express').Response} res
+ * @param {import('express').NextFunction} next
+ * @returns {any}
+ */
+export function defaultToJSONContentType(req, res, next) {
   if (!req.headers['content-type']) {
     req.headers['content-type'] = 'application/json; charset=utf-8';
   }
   next();
 }
 
-function catchAllHandler(err, req, res, next) {
+/**
+ *
+ * @param {import('@appium/types').StringRecord<import('@appium/types').WSServer>} webSocketsMapping
+ * @returns {import('express').RequestHandler}
+ */
+export function handleUpgrade(webSocketsMapping) {
+  return (req, res, next) => {
+    if (!req.headers?.upgrade || _.toLower(req.headers.upgrade) !== 'websocket') {
+      return next();
+    }
+    let currentPathname;
+    try {
+      currentPathname = new URL(req.url ?? '').pathname;
+    } catch {
+      currentPathname = req.url ?? '';
+    }
+    for (const [pathname, wsServer] of _.toPairs(webSocketsMapping)) {
+      if (pathToRegexp(pathname).test(currentPathname)) {
+        return wsServer.handleUpgrade(req, req.socket, Buffer.from(''), (ws) => {
+          wsServer.emit('connection', ws, req);
+        });
+      }
+    }
+    log.info(`Did not match the websocket upgrade request at ${currentPathname} to any known route`);
+    next();
+  };
+}
+
+/**
+ * @param {Error} err
+ * @param {import('express').Request} req
+ * @param {import('express').Response} res
+ * @param {import('express').NextFunction} next
+ */
+export function catchAllHandler(err, req, res, next) {
   if (res.headersSent) {
     return next(err);
   }
@@ -79,7 +137,11 @@ function catchAllHandler(err, req, res, next) {
   log.error(err);
 }
 
-function catch404Handler(req, res) {
+/**
+ * @param {import('express').Request} req
+ * @param {import('express').Response} res
+ */
+export function catch404Handler(req, res) {
   log.debug(`No route found for ${req.url}`);
   const error = errors.UnknownCommandError;
   res.status(error.w3cStatus()).json(
@@ -107,12 +169,4 @@ function patchWithSessionId(req, body) {
   return body;
 }
 
-export {
-  allowCrossDomain,
-  fixPythonContentType,
-  defaultToJSONContentType,
-  catchAllHandler,
-  allowCrossDomainAsyncExecute,
-  handleIdempotency,
-  catch404Handler,
-};
+export { handleIdempotency };

packages/base-driver/lib/express/server.js

@@ -14,6 +14,7 @@ import {
   catchAllHandler,
   allowCrossDomainAsyncExecute,
   handleIdempotency,
+  handleUpgrade,
   catch404Handler,
 } from './middleware';
 import {guineaPig, guineaPigScrollable, guineaPigAppBanner, welcome, STATIC_DIR} from './static';
@@ -109,6 +110,7 @@ async function server(opts) {
         allowCors,
         basePath,
         extraMethodMap,
+        webSocketsMapping: appiumServer.webSocketsMapping,
       });
       // allow extensions to update the app and http server objects
       for (const updater of serverUpdaters) {
@@ -139,6 +141,7 @@ function configureServer({
   allowCors = true,
   basePath = DEFAULT_BASE_PATH,
   extraMethodMap = {},
+  webSocketsMapping = {},
 }) {
   basePath = normalizeBasePath(basePath);
 
@@ -152,7 +155,7 @@ function configureServer({
   app.use(`${basePath}/produce_error`, produceError);
   app.use(`${basePath}/crash`, produceCrash);
 
-  // add middlewares
+  app.use(handleUpgrade(webSocketsMapping));
   if (allowCors) {
     app.use(allowCrossDomain);
   } else {
@@ -195,6 +198,7 @@ function configureHttp({httpServer, reject, keepAliveTimeout}) {
    * @type {AppiumServer}
    */
   const appiumServer = /** @type {any} */ (httpServer);
+  appiumServer.webSocketsMapping = {};
   appiumServer.addWebSocketHandler = addWebSocketHandler;
   appiumServer.removeWebSocketHandler = removeWebSocketHandler;
   appiumServer.removeAllWebSocketHandlers = removeAllWebSocketHandlers;
@@ -370,4 +374,5 @@ export {server, configureServer, normalizeBasePath};
  * @property {boolean} [allowCors]
  * @property {string} [basePath]
  * @property {MethodMap} [extraMethodMap]
+ * @property {import('@appium/types').StringRecord} [webSocketsMapping={}]
  */

packages/base-driver/lib/express/websocket.js

@@ -1,8 +1,6 @@
 /* eslint-disable require-await */
 import _ from 'lodash';
-import {URL} from 'url';
 import B from 'bluebird';
-import { pathToRegexp } from 'path-to-regexp';
 
 const DEFAULT_WS_PATHNAME_PREFIX = '/ws';
 
@@ -11,27 +9,6 @@ const DEFAULT_WS_PATHNAME_PREFIX = '/ws';
  * @type {AppiumServer['addWebSocketHandler']}
  */
 async function addWebSocketHandler(handlerPathname, handlerServer) {
-  if (_.isUndefined(this.webSocketsMapping)) {
-    this.webSocketsMapping = {};
-    // https://github.com/websockets/ws/pull/885
-    this.on('upgrade', (request, socket, head) => {
-      let currentPathname;
-      try {
-        currentPathname = new URL(request.url ?? '').pathname;
-      } catch {
-        currentPathname = request.url ?? '';
-      }
-      for (const [pathname, wsServer] of _.toPairs(this.webSocketsMapping)) {
-        if (pathToRegexp(pathname).test(currentPathname)) {
-          wsServer.handleUpgrade(request, socket, head, (ws) => {
-            wsServer.emit('connection', ws, request);
-          });
-          return;
-        }
-      }
-      socket.destroy();
-    });
-  }
   this.webSocketsMapping[handlerPathname] = handlerServer;
 }
 
@@ -40,10 +17,6 @@ async function addWebSocketHandler(handlerPathname, handlerServer) {
  * @type {AppiumServer['getWebSocketHandlers']}
  */
 async function getWebSocketHandlers(keysFilter = null) {
-  if (_.isEmpty(this.webSocketsMapping)) {
-    return {};
-  }
-
   return _.toPairs(this.webSocketsMapping).reduce((acc, [pathname, wsServer]) => {
     if (!_.isString(keysFilter) || pathname.includes(keysFilter)) {
       acc[pathname] = wsServer;

packages/base-driver/test/e2e/basedriver/websockets.e2e.spec.js

@@ -35,11 +35,9 @@ describe('Websockets (e2e)', function () {
           ws.send(WS_DATA);
         }
       });
-      const previousListenerCount = baseServer.listenerCount('upgrade');
       const endpoint = `${DEFAULT_WS_PATHNAME_PREFIX}/hello`;
       const timeout = 5000;
       await baseServer.addWebSocketHandler(endpoint, wss);
-      baseServer.listenerCount('upgrade').should.be.above(previousListenerCount);
       _.keys(await baseServer.getWebSocketHandlers()).length.should.eql(1);
       await new B((resolve, reject) => {
         const client = new WebSocket(`ws://${TEST_HOST}:${port}${endpoint}`);
@@ -78,7 +76,6 @@ describe('Websockets (e2e)', function () {
         client.on('error', resolve);
         setTimeout(resolve, timeout);
       });
-      baseServer.listenerCount('upgrade').should.be.above(previousListenerCount);
     });
   });
 });

packages/base-driver/test/unit/express/server.spec.js

@@ -59,7 +59,7 @@ describe('server configuration', function () {
     const app = fakeApp();
     const configureRoutes = () => {};
     configureServer({app, addRoutes: configureRoutes});
-    app.use.callCount.should.equal(14);
+    app.use.callCount.should.equal(15);
     app.all.callCount.should.equal(4);
   });