[Fix webpack#1616] Exponential reconnect time when connection fails

Author: Carlos Requena López

client-src/default/socket.js

@@ -2,15 +2,16 @@
 
 const SockJS = require('sockjs-client/dist/sockjs');
 
+// retries variable must increment after each failed reconnection.
+// reconnect time depends on it
+// See https://github.com/webpack/webpack-dev-server/pull/1617
 let retries = 0;
 let sock = null;
 
 const socket = function initSocket(url, handlers) {
   sock = new SockJS(url);
 
-  sock.onopen = function onopen() {
-    retries = 0;
-  };
+  sock.onopen = function onopen() {};
 
   sock.onclose = function onclose() {
     if (retries === 0) {

test/Socket.test.js

@@ -3,6 +3,7 @@
 const request = require('supertest');
 const config = require('./fixtures/simple-config/webpack.config');
 const helper = require('./helper');
+const socket = require('../client-src/default/socket.js');
 
 describe('socket options', () => {
   let server;
@@ -28,6 +29,23 @@ describe('socket options', () => {
     });
   });
 
+  describe('failing behaviour', () => {
+    beforeEach((done) => {
+      server = helper.start(config, {}, done);
+      req = request('http://localhost:8080');
+    });
+
+    it('should increase reconnect time exponentially', () => {
+      // TODO
+      // Try to connect to websocket server, ideally with a different
+      // origin so it fails to connect
+      socket("http://localhost:8080/sockjs-node/123/456/websocket");
+      // Inspect socket (retries or retryInMs) to make sure it waits
+      // an exponential amount of time and retries variable increases
+      // every time
+    });
+  });
+
   describe('socksPath option', () => {
     const path = '/foo/test/bar';
     beforeEach((done) => {