根据Web3文档:

如果你使用的是create-react-app版本>=5，你可能会遇到构建问题。这是因为最新版本的create-react-app中没有包含NodeJS的polyfills。

解决方案:

安装react-app-rewired和缺少的模块

如果你用的是纱线:

yarn add --dev react-app-rewired crypto-browserify stream-browserify assert stream-http https-browserify os-browserify url buffer process

如果你正在使用npm:

npm install --save-dev react-app-rewired crypto-browserify stream-browserify assert stream-http https-browserify os-browserify url buffer process

在项目文件夹的根目录下创建config-override .js，内容如下:

const webpack = require('webpack');

module.exports = function override(config) {
    const fallback = config.resolve.fallback || {};
    Object.assign(fallback, {
        "crypto": require.resolve("crypto-browserify"),
        "stream": require.resolve("stream-browserify"),
        "assert": require.resolve("assert"),
        "http": require.resolve("stream-http"),
        "https": require.resolve("https-browserify"),
        "os": require.resolve("os-browserify"),
        "url": require.resolve("url")
    })
    config.resolve.fallback = fallback;
    config.plugins = (config.plugins || []).concat([
        new webpack.ProvidePlugin({
            process: 'process/browser',
            Buffer: ['buffer', 'Buffer']
        })
    ])
    return config;
}

内包。Json改变脚本字段启动，构建和测试。用react-app-rewired代替react-scripts 之前:

"scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
},

后:

"scripts": {
    "start": "react-app-rewired start",
    "build": "react-app-rewired build",
    "test": "react-app-rewired test",
    "eject": "react-scripts eject"
},

缺少的Nodejs polyfills现在应该包括在内，你的应用程序应该可以使用web3。

如果你想隐藏控制台创建的警告:

在config-override .js的override函数中，添加:

config.ignoreWarnings = [/Failed to parse source map/];

对我来说，我只是删除了一个未使用的导入，称为:

import res from "express/lib/response"

它把它修好了!

当从webpack v4升级到v5时，我也得到了这些错误。 通过对webpack.config.js进行以下更改来解决

添加的决心。回退财产

删除节点属性

{
resolve: {
  modules: [...],
  fallback: {
    "fs": false,
    "tls": false,
    "net": false,
    "path": false,
    "zlib": false,
    "http": false,
    "https": false,
    "stream": false,
    "crypto": false,
    "crypto-browserify": require.resolve('crypto-browserify'), //if you want to use this module also don't forget npm i crypto-browserify 
  } 
},
entry: [...],
output: {...},
module: {
  rules: [...]
},
plugins: [...],
optimization: {
  minimizer: [...],
},
// node: {
//   fs: 'empty',
//   net: 'empty',
//   tls: 'empty'
// },
}

从v4升级到v5 => https://webpack.js.org/migrate/5/#clean-up-configuration

我的环境是这样的:

React => v17 React脚本=> v5 Webpack => v5

要解决这个问题，请遵循下面的说明

1-安装以下软件包

yarn add fs assert https-browserify os os-browserify stream-browserify stream-http react-app-rewired

2-在项目根目录下package.json旁边创建config-coverrides.js

添加以下代码:

const webpack = require('webpack'); module.exports = function override(config, env) { config.resolve.fallback = { url: require.resolve('url'), fs: require.resolve('fs'), assert: require.resolve('assert'), crypto: require.resolve('crypto-browserify'), http: require.resolve('stream-http'), https: require.resolve('https-browserify'), os: require.resolve('os-browserify/browser'), buffer: require.resolve('buffer'), stream: require.resolve('stream-browserify'), }; config.plugins.push( new webpack.ProvidePlugin({ process: 'process/browser', Buffer: ['buffer', 'Buffer'], }), ); return config; }

3-像下面这样修改packages.js

"脚本":{ “start”:“react-app-rewired start”， “build”:“react-app-rewired build”， “test”:“react-app-rewired test” "eject": "react-app-rewired eject" }，

我在create-react-app中遇到了这个问题

"react": "^17.0.2",
"react-dom": "^17.0.2",
"react-scripts": "5.0.0",
"web-vitals": "^2.1.2"

我通过将react-scripts更改为4.0.3版本来解决这个问题。

对于我(使用React => v17;React脚本=> v5;webpack => v5)，由@Letton和@Richie Bendall建议的解决方案组合与另一个附加，即包一起工作。Json中，必须添加并安装以下包。还请注意fs版本“^2.0.0”抛出一个错误，因此更改为“0.0.1-security”。

"assert": "^2.0.0", 
"https-browserify": "^1.0.0", 
"os": "^0.1.2",
"os-browserify": "^0.3.0",
"react-app-rewired": "^2.1.9",
"stream-browserify": "^3.0.0",
"stream-http": "^3.2.0",
"fs":"^0.0.1-security",
"crypto-browserify": "3.12.0",
"buffer":"^6.0.3",
"node-polyfill-webpack-plugin": "^2.0.1"

安装完这些后，执行剩下的步骤，即将config-override .js添加到根目录，并更改包中的脚本内容。从react-scripts到react-app-rewired的Json修复了这个问题。