模块解析失败：在部署Heroku时出现意外令牌（14：6）

Question

我有一个计划部署到Heroku的简单应用。它可以在localhost上运行，但是在执行git push heroku master时出现错误，提示需要适当的加载程序来处理此文件类型，当前未配置任何加载程序来处理此文件。我也尝试将<>更改为<div>或<React.Fragment>等，但是没有运气。

      |   render() {
      |     return (
     >       <>
      |         <Sidebar/>
      |         <Footer/>
      |      </>
       @ ./src/index.js 1:0-24

我在这里查看了大多数答案，并且我的配置看起来正确。任何解决方案为何仍在抱怨？

。babelrc文件

{
  "presets": [
    "@babel/preset-env", 
    "@babel/preset-react"
  ]
}

webpack.config.js

const htmlWebPackPlugin = require("html-webpack-plugin");
module.exports = {
  output: {
    publicPath: '/'
  },
  module: {
    rules: [
      {
        test: /.jsx?$/, 
        exclude: /(node_modules|bower_components)/,
        use: {
          loader: "babel-loader",
          options: {
            presets: ["@babel/preset-react"]
          }
        }
      },
      {
        test: /.html$/,
        use: [
          {
            loader: "html-loader"
          }
        ]
      },
      {
        test: /.(png|svg|jpg|gif)$/,
        use: ["file-loader"]
      },
      {
        test: /.css$/,
        use: [
          'style-loader',
          'css-loader'
        ]
      },
    ]
  },
  resolve: {
    extensions: ['*', '.js', '.jsx']
  },
  devServer: {
    historyApiFallback: true,
  },
  plugins: [
    new HtmlWebPackPlugin({
      template: "./src/index.html",
      filename: "./index.html"
    })
  ]
};

package.json

{
  "name": "myWebsite",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "engines": {
    "npm": "6.12.0",
    "node": "12.13.0"
  },
  "scripts": {
    "test": "echo "Error: no test specified" && exit 1",
    "start": "webpack-dev-server --open --mode development",
    "build": "webpack --mode production"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/preset-env": "^7.6.3",
    "@babel/preset-react": "^7.6.3",
    "css-loader": "^3.2.0",
    "file-loader": "^4.2.0",
    "html-loader": "^0.5.5",
    "html-webpack-plugin": "^3.2.0",
    "react-social-icons": "^4.1.0",
    "style-loader": "^1.0.0",
    "webpack": "^4.41.2",
    "webpack-cli": "^3.3.9",
    "webpack-dev-server": "^3.8.2"
  },
  "dependencies": {
    "@babel/core": "^7.6.4",
    "babel-loader": "^8.0.6",
    "react": "^16.10.2",
    "react-dom": "^16.10.2",
    "react-router-dom": "^5.1.2",
    "react-split-pane": "^0.1.87"
  }
}

根据要求，这是我的完整错误输出

Enumerating objects: 68, done.
Counting objects: 100% (68/68), done.
Delta compression using up to 4 threads
Compressing objects: 100% (65/65), done.
Writing objects: 100% (68/68), 1.17 MiB | 765.00 KiB/s, done.
Total 68 (delta 23), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Node.js app detected
remote:
remote: -----> Creating runtime environment
remote:
remote:        NPM_CONFIG_LOGLEVEL=error
remote:        NODE_ENV=production
remote:        NODE_MODULES_CACHE=true
remote:        NODE_VERBOSE=false
remote:
remote: -----> Installing binaries
remote:        engines.node (package.json):  12.13.0
remote:        engines.npm (package.json):   6.12.0
remote:
remote:        Resolving node version 12.13.0...
remote:        Downloading and installing node 12.13.0...
remote:        npm 6.12.0 already installed with node
remote:
remote: -----> Installing dependencies
remote:        Installing node modules (package.json)
remote:        added 823 packages from 403 contributors and audited 10614 packages in 25.88s
remote:        found 0 vulnerabilities
remote:
remote:
remote: -----> Build
remote:        Running build
remote:
remote:        > myWebsite@1.0.0 build /tmp/build_aecdb33dae6f65fc1053619440b756ef
remote:        > webpack --mode production
remote:
remote:        Hash: 71478ca5630665d9995b
remote:        Version: webpack 4.41.2
remote:        Time: 205ms
remote:        Built at: 11/07/2019 7:44:19 PM
remote:         1 asset
remote:        Entrypoint main = main.js
remote:        [0] ./src/index.js 24 bytes {0} [built]
remote:        [1] ./src/App.js 315 bytes {0} [built] [failed] [1 error]
remote:
remote:        ERROR in ./src/App.js 14:6
remote:        Module parse failed: Unexpected token (14:6)
remote:        You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
remote:        |   render() {
remote:        |     return (
remote:        >       <>
remote:        |         <Sidebar/>
remote:        |         <Footer/>
remote:         @ ./src/index.js 1:0-24
remote: npm ERR! code ELIFECYCLE
remote: npm ERR! errno 2
remote: npm ERR! myWebsite@1.0.0 build: `webpack --mode production`
remote: npm ERR! Exit status 2
remote: npm ERR!
remote: npm ERR! Failed at the myWebsite@1.0.0 build script.
remote: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
remote:
remote: npm ERR! A complete log of this run can be found in:
remote: npm ERR!     /tmp/npmcache.7aIPm/_logs/2019-11-07T19_44_19_386Z-debug.log
remote:
remote: -----> Build failed
remote:
remote:        We're sorry this build is failing! You can troubleshoot common issues here:
remote:        https://devcenter.heroku.com/articles/troubleshooting-node-deploys
remote:
remote:        If you're stuck, please submit a ticket so we can help:
remote:        https://help.heroku.com/
remote:
remote:        Love,
remote:        Heroku
remote:
remote:  !     Push rejected, failed to compile Node.js app.
remote:
remote:  !     Push failed
remote: Verifying deploy...
remote:
remote: !   Push rejected to guarded-fortress-36341.
remote:
To https://git.heroku.com/guarded-fortress-36341.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/guarded-fortress-36341.git'