enforce ES5 in all client files, fix usage in ES5 only browsers

client/.eslintrc

@@ -1,5 +1,10 @@
 {
+  "parserOptions": {
+    "ecmaVersion": 5
+  },
   "rules": {
+    "no-var": ["off"],
+    "vars-on-top": ["off"],
     "object-shorthand": ["error", "never"],
     "prefer-arrow-callback": ["off"],
     "prefer-template": ["off"]

client/index.js

@@ -3,36 +3,36 @@
 /* global __resourceQuery WorkerGlobalScope self */
 /* eslint prefer-destructuring: off */
 
-const url = require('url');
-const stripAnsi = require('strip-ansi');
-const log = require('loglevel').getLogger('webpack-dev-server');
-const socket = require('./socket');
-const overlay = require('./overlay');
+var url = require('url');
+var stripAnsi = require('strip-ansi');
+var log = require('loglevel').getLogger('webpack-dev-server');
+var socket = require('./socket');
+var overlay = require('./overlay');
 
 function getCurrentScriptSource() {
   // `document.currentScript` is the most accurate way to find the current script,
   // but is not supported in all browsers.
   if (document.currentScript) { return document.currentScript.getAttribute('src'); }
   // Fall back to getting all scripts in the document.
-  const scriptElements = document.scripts || [];
-  const currentScript = scriptElements[scriptElements.length - 1];
+  var scriptElements = document.scripts || [];
+  var currentScript = scriptElements[scriptElements.length - 1];
   if (currentScript) { return currentScript.getAttribute('src'); }
   // Fail as there was no script to use.
   throw new Error('[WDS] Failed to get current script source.');
 }
 
-let urlParts;
-let hotReload = true;
+var urlParts;
+var hotReload = true;
 if (typeof window !== 'undefined') {
-  const qs = window.location.search.toLowerCase();
+  var qs = window.location.search.toLowerCase();
   hotReload = qs.indexOf('hotreload=false') === -1;
 }
 if (typeof __resourceQuery === 'string' && __resourceQuery) {
   // If this bundle is inlined, use the resource query to get the correct url.
   urlParts = url.parse(__resourceQuery.substr(1));
 } else {
   // Else, get the url from the <script> this file was called with.
-  let scriptHost = getCurrentScriptSource();
+  var scriptHost = getCurrentScriptSource();
   // eslint-disable-next-line no-useless-escape
   scriptHost = scriptHost.replace(/\/[^\/]+$/, '');
   urlParts = url.parse((scriptHost || '/'), false, true);
@@ -42,17 +42,17 @@ if (!urlParts.port || urlParts.port === '0') {
   urlParts.port = self.location.port;
 }
 
-let hot = false;
-let initial = true;
-let currentHash = '';
-let useWarningOverlay = false;
-let useErrorOverlay = false;
-let useProgress = false;
+var hot = false;
+var initial = true;
+var currentHash = '';
+var useWarningOverlay = false;
+var useErrorOverlay = false;
+var useProgress = false;
 
-const INFO = 'info';
-const WARNING = 'warning';
-const ERROR = 'error';
-const NONE = 'none';
+var INFO = 'info';
+var WARNING = 'warning';
+var ERROR = 'error';
+var NONE = 'none';
 
 // Set the default log level
 log.setDefaultLevel(INFO);
@@ -71,7 +71,7 @@ function sendMsg(type, data) {
   }
 }
 
-const onSocketMsg = {
+var onSocketMsg = {
   hot: function msgHot() {
     hot = true;
     log.info('[WDS] Hot Module Replacement enabled.');
@@ -91,7 +91,7 @@ const onSocketMsg = {
     sendMsg('StillOk');
   },
   'log-level': function logLevel(level) {
-    const hotCtx = require.context('webpack/hot', false, /^\.\/log$/);
+    var hotCtx = require.context('webpack/hot', false, /^\.\/log$/);
     if (hotCtx.keys().indexOf('./log') !== -1) {
       hotCtx('./log').setLogLevel(level);
     }
@@ -142,19 +142,19 @@ const onSocketMsg = {
   },
   warnings: function msgWarnings(warnings) {
     log.warn('[WDS] Warnings while compiling.');
-    const strippedWarnings = warnings.map(function map(warning) { return stripAnsi(warning); });
+    var strippedWarnings = warnings.map(function map(warning) { return stripAnsi(warning); });
     sendMsg('Warnings', strippedWarnings);
-    for (let i = 0; i < strippedWarnings.length; i++) { log.warn(strippedWarnings[i]); }
+    for (var i = 0; i < strippedWarnings.length; i++) { log.warn(strippedWarnings[i]); }
     if (useWarningOverlay) overlay.showMessage(warnings);
 
     if (initial) return initial = false; // eslint-disable-line no-return-assign
     reloadApp();
   },
   errors: function msgErrors(errors) {
     log.error('[WDS] Errors while compiling. Reload prevented.');
-    const strippedErrors = errors.map(function map(error) { return stripAnsi(error); });
+    var strippedErrors = errors.map(function map(error) { return stripAnsi(error); });
     sendMsg('Errors', strippedErrors);
-    for (let i = 0; i < strippedErrors.length; i++) { log.error(strippedErrors[i]); }
+    for (var i = 0; i < strippedErrors.length; i++) { log.error(strippedErrors[i]); }
     if (useErrorOverlay) overlay.showMessage(errors);
   },
   error: function msgError(error) {
@@ -166,8 +166,8 @@ const onSocketMsg = {
   }
 };
 
-let hostname = urlParts.hostname;
-let protocol = urlParts.protocol;
+var hostname = urlParts.hostname;
+var protocol = urlParts.protocol;
 
 
 // check ipv4 and ipv6 `all hostname`
@@ -189,7 +189,7 @@ if (hostname && (self.location.protocol === 'https:' || urlParts.hostname === '0
   protocol = self.location.protocol;
 }
 
-const socketUrl = url.format({
+var socketUrl = url.format({
   protocol: protocol,
   auth: urlParts.auth,
   hostname: hostname,
@@ -199,7 +199,7 @@ const socketUrl = url.format({
 
 socket(socketUrl, onSocketMsg);
 
-let isUnloading = false;
+var isUnloading = false;
 self.addEventListener('beforeunload', function beforeUnload() {
   isUnloading = true;
 });
@@ -211,16 +211,16 @@ function reloadApp() {
   if (hot) {
     log.info('[WDS] App hot update...');
     // eslint-disable-next-line global-require
-    const hotEmitter = require('webpack/hot/emitter');
+    var hotEmitter = require('webpack/hot/emitter');
     hotEmitter.emit('webpackHotUpdate', currentHash);
     if (typeof self !== 'undefined' && self.window) {
       // broadcast update to window
       self.postMessage('webpackHotUpdate' + currentHash, '*');
     }
   } else {
-    let rootWindow = self;
+    var rootWindow = self;
     // use parent window for reload (in case we're in an iframe with no valid src)
-    const intervalId = self.setInterval(function findRootWindow() {
+    var intervalId = self.setInterval(function findRootWindow() {
       if (rootWindow.location.protocol !== 'about:') {
         // reload immediately if protocol is valid
         applyReload(rootWindow, intervalId);
@@ -234,9 +234,9 @@ function reloadApp() {
     });
   }
 
-  function applyReload(rootWindow, intervalId) {
-    clearInterval(intervalId);
+  function applyReload(window, id) {
+    clearInterval(id);
     log.info('[WDS] App updated. Reloading...');
-    rootWindow.location.reload();
+    window.location.reload();
   }
 }

client/live.js

@@ -2,23 +2,23 @@
 
 /* eslint import/no-extraneous-dependencies: off, global-require: off */
 
-const $ = require('jquery');
-const stripAnsi = require('strip-ansi');
-const socket = require('./socket');
+var $ = require('jquery');
+var stripAnsi = require('strip-ansi');
+var socket = require('./socket');
 require('./style.css');
 
-let hot = false;
-let currentHash = '';
+var hot = false;
+var currentHash = '';
 
 $(function ready() {
   $('body').html(require('./page.pug')());
-  const status = $('#status');
-  const okness = $('#okness');
-  const $errors = $('#errors');
-  const iframe = $('#iframe');
-  const header = $('.header');
+  var status = $('#status');
+  var okness = $('#okness');
+  var $errors = $('#errors');
+  var iframe = $('#iframe');
+  var header = $('.header');
 
-  const contentPage = window.location.pathname.substr('/webpack-dev-server'.length) + window.location.search;
+  var contentPage = window.location.pathname.substr('/webpack-dev-server'.length) + window.location.search;
 
   status.text('Connecting to sockjs server...');
   $errors.hide();
@@ -27,7 +27,7 @@ $(function ready() {
     borderColor: '#96b5b4'
   });
 
-  const onSocketMsg = {
+  var onSocketMsg = {
     hot: function msgHot() {
       hot = true;
       iframe.attr('src', contentPage + window.location.hash);
@@ -110,7 +110,7 @@ $(function ready() {
         borderColor: '#96b5b4'
       });
       try {
-        let old = iframe[0].contentWindow.location + '';
+        var old = iframe[0].contentWindow.location + '';
         if (old.indexOf('about') === 0) old = null;
         iframe.attr('src', old || (contentPage + window.location.hash));
         if (old) {

client/overlay.js

@@ -3,12 +3,12 @@
 // The error overlay is inspired (and mostly copied) from Create React App (https://github.com/facebookincubator/create-react-app)
 // They, in turn, got inspired by webpack-hot-middleware (https://github.com/glenjamin/webpack-hot-middleware).
 
-const ansiHTML = require('ansi-html');
-const Entities = require('html-entities').AllHtmlEntities;
+var ansiHTML = require('ansi-html');
+var Entities = require('html-entities').AllHtmlEntities;
 
-const entities = new Entities();
+var entities = new Entities();
 
-const colors = {
+var colors = {
   reset: ['transparent', 'transparent'],
   black: '181818',
   red: 'E36049',
@@ -23,7 +23,7 @@ const colors = {
 ansiHTML.setColors(colors);
 
 function createOverlayIframe(onIframeLoad) {
-  const iframe = document.createElement('iframe');
+  var iframe = document.createElement('iframe');
   iframe.id = 'webpack-dev-server-client-overlay';
   iframe.src = 'about:blank';
   iframe.style.position = 'fixed';
@@ -40,7 +40,7 @@ function createOverlayIframe(onIframeLoad) {
 }
 
 function addOverlayDivTo(iframe) {
-  const div = iframe.contentDocument.createElement('div');
+  var div = iframe.contentDocument.createElement('div');
   div.id = 'webpack-dev-server-client-overlay-div';
   div.style.position = 'fixed';
   div.style.boxSizing = 'border-box';
@@ -62,9 +62,9 @@ function addOverlayDivTo(iframe) {
   return div;
 }
 
-let overlayIframe = null;
-let overlayDiv = null;
-let lastOnOverlayDivReady = null;
+var overlayIframe = null;
+var overlayDiv = null;
+var lastOnOverlayDivReady = null;
 
 function ensureOverlayDivExists(onOverlayDivReady) {
   if (overlayDiv) {

client/socket.js

@@ -1,9 +1,9 @@
 'use strict';
 
-const SockJS = require('sockjs-client/dist/sockjs');
+var SockJS = require('sockjs-client/dist/sockjs');
 
-let retries = 0;
-let sock = null;
+var retries = 0;
+var sock = null;
 
 function socket(url, handlers) {
   sock = new SockJS(url);
@@ -23,7 +23,7 @@ function socket(url, handlers) {
       // Exponentially increase timeout to reconnect.
       // Respectfully copied from the package `got`.
       // eslint-disable-next-line no-mixed-operators, no-restricted-properties
-      const retryInMs = 1000 * Math.pow(2, retries) + Math.random() * 100;
+      var retryInMs = 1000 * Math.pow(2, retries) + Math.random() * 100;
       retries += 1;
 
       setTimeout(function cb() {
@@ -34,7 +34,7 @@ function socket(url, handlers) {
 
   sock.onmessage = function onmessage(e) {
     // This assumes that all data sent via the websocket is JSON.
-    const msg = JSON.parse(e.data);
+    var msg = JSON.parse(e.data);
     if (handlers[msg.type]) { handlers[msg.type](msg.data); }
   };
 }

package.json

@@ -22,7 +22,7 @@
     "beautify": "npm run lint -- --fix",
     "ci": "npm run cover -- --report lcovonly && npm run test",
     "cover": "istanbul cover node_modules/mocha/bin/_mocha",
-    "lint": "eslint bin lib test examples client/{index,live,socket,sockjs,overlay,webpack.config}.js",
+    "lint": "eslint bin lib test examples client/{index,live,socket,sockjs,overlay}.js",
     "mocha": "mocha --full-trace --check-leaks",
     "prepublish": "(rm ssl/*.pem || true) && npm run -s build:live && npm run -s build:index && npm run -s build:sockjs",
     "test": "npm run lint && npm run mocha",