feat(client): introduce core-js

Author: hiroppy

client-src/default/index.js

@@ -9,6 +9,7 @@ import { log, setLogLevel } from './utils/log';
 import sendMessage from './utils/sendMessage';
 import reloadApp from './utils/reloadApp';
 import createSocketUrl from './utils/createSocketUrl';
+import { array, string } from './polyfill';
 
 const status = {
   isUnloading: false,
@@ -31,7 +32,7 @@ self.addEventListener('beforeunload', () => {
 
 if (typeof window !== 'undefined') {
   const qs = window.location.search.toLowerCase();
-  options.hotReload = qs.indexOf('hotreload=false') === -1;
+  options.hotReload = !string.includes(qs, 'hotreload=false');
 }
 
 const onSocketMessage = {
@@ -63,7 +64,7 @@ const onSocketMessage = {
   },
   'log-level': function logLevel(level) {
     const hotCtx = require.context('webpack/hot', false, /^\.\/log$/);
-    if (hotCtx.keys().indexOf('./log') !== -1) {
+    if (array.includes(hotCtx.keys(), './log')) {
       hotCtx('./log').setLogLevel(level);
     }
     setLogLevel(level);

client-src/default/polyfill.js

@@ -0,0 +1,10 @@
+import stringIncludes from 'core-js/features/string/includes';
+import arrayIncludes from 'core-js/features/array/includes';
+
+export const array = {
+  includes: arrayIncludes,
+};
+
+export const string = {
+  includes: stringIncludes,
+};

package-lock.json

@@ -40,6 +40,7 @@
     "chokidar": "^3.0.1",
     "compression": "^1.7.4",
     "connect-history-api-fallback": "^1.6.0",
+    "core-js": "^3.1.3",
     "debug": "^4.1.1",
     "del": "^4.1.1",
     "express": "^4.17.1",