我正在使用craco的create-react-app，在升级到webpack 5时遇到了以下错误:

“缓冲”

Module not found: Error: Can't resolve 'buffer' in '/Users/therightstuff/my-project/node_modules/safe-buffer'

BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.

If you want to include a polyfill, you need to:
    - add a fallback 'resolve.fallback: { "buffer": require.resolve("buffer/") }'
    - install 'buffer'
If you don't want to include a polyfill, you can use an empty module like this:
    resolve.fallback: { "buffer": false }

这个问题通过安装npm install -D buffer来解决。

'fs'

Module not found: Error: Can't resolve 'fs' in '/Users/therightstuff/my-project/node_modules/line-navigator'

这个问题通过在craco配置craco.config.js中设置webpack回退来解决:

module.exports = {
    style: {
        postcssOptions: {
            plugins: [
            require('tailwindcss'),
            require('autoprefixer'),
            ],
        },
    },
    webpack: {
        configure: (webpackConfig, { env, paths }) => {
            // eslint-disable-next-line no-param-reassign
            webpackConfig.resolve.fallback = {
                fs: false,
            };
            return webpackConfig;
        },
    },
}

Create React App刚刚发布了v5，现在实现了Webpack v5。这将完全打破许多库，其中包括web3作为必需的节点核心库腻子将会丢失。

为了快速解决这个问题，你可以在package.json中修改这个:

"react-scripts": "^5.0.0"

这个

"react-scripts": "4.0.3"

在这之后:

rm -r node_modules

rm package-lock.json

npm install

我喜欢把事情简单化，在这里之前不需要运行npm run-script eject，所以我降级回react-scripts@4.0.3而不是5.0.0 到目前为止，Webpack仍然没有解决这个问题

可悲的是，因为这包括一堆退役的包裹。

你想用在

const nodeExternals = require('webpack-node-externals');

在webpack.config.js中添加

target: "node",
devtool: "source-map",
externals: [nodeExternals()],

错误:[webpack < 5用于默认包含node.js核心模块的腻子。

现在情况已经不同了。验证你是否需要这个模块，并为它配置一个填充。

答: Node_modules > react-scripts > config > webpack.config.js

在webpack.config.js文件中添加:

resolve: {
      fallback: { 
        "http": require.resolve("stream-http") ,
         "path": require.resolve("path-browserify") 
        },
}

NPM install path-browserify 然后尝试更改webpack配置以包括:

module.exports = {
    ...
    resolve: {
        alias: {
            path: require.resolve("path-browserify")
        }
    }
};