refactor: replace deprecated String.prototype.substr()

.substr() is deprecated so we replace it with .slice() which works similarily but isn't deprecated

Signed-off-by: Tobias Speicher <rootcommander@gmail.com>

client/main.js

@@ -15,7 +15,7 @@ var socket = io(location.host, {
   reconnectionDelay: 500,
   reconnectionDelayMax: Infinity,
   timeout: BROWSER_SOCKET_TIMEOUT,
-  path: KARMA_PROXY_PATH + KARMA_URL_ROOT.substr(1) + 'socket.io',
+  path: KARMA_PROXY_PATH + KARMA_URL_ROOT.slice(1) + 'socket.io',
   'sync disconnect on unload': true,
   useNativeTimers: true
 })

common/util.js

@@ -20,7 +20,7 @@ exports.isDefined = function (value) {
 
 exports.parseQueryParams = function (locationSearch) {
   var params = {}
-  var pairs = locationSearch.substr(1).split('&')
+  var pairs = locationSearch.slice(1).split('&')
   var keyValue
 
   for (var i = 0; i < pairs.length; i++) {

lib/completion.js

@@ -36,7 +36,7 @@ const options = {
 
 function opositeWord (word) {
   if (word.startsWith('-')) {
-    return word.startsWith('--no-') ? `--${word.substr(5)}` : `--no-${word.substr(2)}`
+    return word.startsWith('--no-') ? `--${word.slice(5)}` : `--no-${word.slice(2)}`
   } else {
     return null
   }

lib/events.js

@@ -35,7 +35,7 @@ class KarmaEventEmitter extends EventEmitter {
   bind (object) {
     for (const method in object) {
       if (method.startsWith('on') && helper.isFunction(object[method])) {
-        this.on(helper.camelToSnake(method.substr(2)), function () {
+        this.on(helper.camelToSnake(method.slice(2)), function () {
           // We do not use an arrow function here, to supply the caller as this.
           object[method].apply(object, Array.from(arguments).concat(this))
         })

lib/helper.js

@@ -96,7 +96,7 @@ exports.camelToSnake = (camelCase) => {
 }
 
 exports.ucFirst = (word) => {
-  return word.charAt(0).toUpperCase() + word.substr(1)
+  return word.charAt(0).toUpperCase() + word.slice(1)
 }
 
 exports.dashToCamel = (dash) => {

lib/launcher.js

@@ -60,7 +60,7 @@ class Launcher {
       protocol = upstreamProxy.protocol
       hostname = upstreamProxy.hostname
       port = upstreamProxy.port
-      urlRoot = upstreamProxy.path + urlRoot.substr(1)
+      urlRoot = upstreamProxy.path + urlRoot.slice(1)
     }
 
     return (name) => {

lib/middleware/karma.js

@@ -32,9 +32,9 @@ const FILE_TYPES = [
 
 function filePathToUrlPath (filePath, basePath, urlRoot, proxyPath) {
   if (filePath.startsWith(basePath)) {
-    return proxyPath + urlRoot.substr(1) + 'base' + filePath.substr(basePath.length)
+    return proxyPath + urlRoot.slice(1) + 'base' + filePath.slice(basePath.length)
   }
-  return proxyPath + urlRoot.substr(1) + 'absolute' + filePath
+  return proxyPath + urlRoot.slice(1) + 'absolute' + filePath
 }
 
 function getQuery (urlStr) {
@@ -85,8 +85,8 @@ function createKarmaMiddleware (
     const requestedRangeHeader = request.headers.range
 
     // redirect /__karma__ to /__karma__ (trailing slash)
-    if (requestUrl === urlRoot.substr(0, urlRoot.length - 1)) {
-      response.setHeader('Location', proxyPath + urlRoot.substr(1))
+    if (requestUrl === urlRoot.slice(0, -1)) {
+      response.setHeader('Location', proxyPath + urlRoot.slice(1))
       response.writeHead(301)
       return response.end('MOVED PERMANENTLY')
     }
@@ -97,7 +97,7 @@ function createKarmaMiddleware (
     }
 
     // remove urlRoot prefix
-    requestUrl = requestUrl.substr(urlRoot.length - 1)
+    requestUrl = requestUrl.slice(urlRoot.length - 1)
 
     // serve client.html
     if (requestUrl === '/') {

lib/runner.js

@@ -18,9 +18,9 @@ function parseExitCode (buffer, defaultExitCode, failOnEmptyTestSuite) {
 
   const tail = buffer.slice(tailPos)
   const tailStr = tail.toString()
-  if (tailStr.substr(0, tailStr.length - 2) === constant.EXIT_CODE) {
-    const emptyInt = parseInt(tailStr.substr(-2, 1), 10)
-    let exitCode = parseInt(tailStr.substr(-1), 10)
+  if (tailStr.slice(0, -2) === constant.EXIT_CODE) {
+    const emptyInt = parseInt(tailStr.slice(-2, -1), 10)
+    let exitCode = parseInt(tailStr.slice(-1), 10)
     if (failOnEmptyTestSuite === false && emptyInt === 0) {
       log.warn('Test suite was empty.')
       exitCode = 0