webpack5的小伙伴，报错看这里，我解决了。下面引入的模块都需要自己手动去安装以下，其中process/browser，这是两个，分开装。 

const path = require("path");

const nodeExcternals = require("webpack-node-externals");

const { CleanWebpackPlugin } = require("clean-webpack-plugin");

const webpackconfig = {

    target: "node",

    mode: "development",

    entry: {

        server: path.join(__dirname, "index.js"),

    },

    output: {

        filename: "[name].bundle.js",

        path: path.join(__dirname, "./dist"),

    },

    devtool: "eval-source-map",

    module: {

        rules: [

            {

                test: /\.(js|jsx)$/,

                use: {

                    loader: "babel-loader",

                },

                exclude: [path.join(__dirname, "/node_modules")],

            },

        ],

    },

    externals: [nodeExcternals()],

    plugins: [new CleanWebpackPlugin()],

    node: {

        global: true,

        __filename: true,

        __dirname: true,

    },

    resolve: {

        fallback: {

            console: require.resolve("console-browserify"),

            process: require.resolve("process/browser"),

            buffer: require.resolve("buffer"),

            path: require.resolve("path-browserify"),

            setImmediate: require.resolve("setimmediate"),

        },

    },

};

module.exports = webpackconfig;