fix ASSET_PATH for webpack 5

Author: lxieyang

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "chrome-extension-boilerplate-react",
-  "version": "3.1.1",
+  "version": "3.1.2",
   "description": "A chrome extension boilerplate built with React 17 and Webpack 4",
   "license": "MIT",
   "repository": {

package.json

@@ -1,6 +1,7 @@
 // Do this as the first thing so that any code reading it knows the right env.
 process.env.BABEL_ENV = 'production';
 process.env.NODE_ENV = 'production';
+process.env.ASSET_PATH = '/';
 
 var webpack = require('webpack'),
   config = require('../webpack.config');

utils/build.js

@@ -1,6 +1,7 @@
 // Do this as the first thing so that any code reading it knows the right env.
 process.env.BABEL_ENV = 'development';
 process.env.NODE_ENV = 'development';
+process.env.ASSET_PATH = '/';
 
 var WebpackDevServer = require('webpack-dev-server'),
   webpack = require('webpack'),

utils/webserver.js

@@ -7,6 +7,8 @@ var webpack = require('webpack'),
   HtmlWebpackPlugin = require('html-webpack-plugin'),
   TerserPlugin = require('terser-webpack-plugin');
 
+const ASSET_PATH = process.env.ASSET_PATH || '/';
+
 var alias = {
   'react-dom': '@hot-loader/react-dom',
 };
@@ -46,6 +48,7 @@ var options = {
   output: {
     path: path.resolve(__dirname, 'build'),
     filename: '[name].bundle.js',
+    publicPath: ASSET_PATH,
   },
   module: {
     rules: [