webpack.config.js

const path = require("path");
const CleanWebPackPlugin = require("clean-webpack-plugin");
const HtmlWebPackPlugin = require("html-webpack-plugin");

module.exports = {
  entry: "./src/index.js",
  output: {
    filename: "bundle.js",
    path: path.resolve(__dirname, "public"),
  },
  module: {
    rules: [
      {
          enforce: 'pre',
          test: /\.js$/,
          loader: 'eslint-loader',
          options: {
              failOnWarning: true,
              failOnerror: true
          },
          exclude: /node_modules/
      },
      {
        test: /\.js$/,
        loader: "babel-loader",
        exclude: /node_modules/,
      },
      {
        test: /\.s?css$/,
        use: [
          "style-loader",
          "css-loader",
          {
            loader: "postcss-loader",
            options: {
              postcssOptions: {
                plugins: [
                  [
                    "postcss-preset-env",
                    {
                      // Options
                    },
                  ],
                ],
              },
            },
          },
        ],
        exclude: /node_modules/,
      },
      {
        test: /\.svg$/,
        loader: "url-loader",
        exclude: /node_modules/,
      },
    ],
  },
  plugins: [
    new CleanWebPackPlugin(["public"], { root: path.resolve(__dirname) }),
    new HtmlWebPackPlugin({
      template: "./src/index.html",
      favicon: "./src/favicon.ico",
      inject: false,
    }),
  ],
  devtool: "eval",
  devServer: {
    contentBase: path.resolve(__dirname, "public"),
    compress: true,
    port: 9000,
  },
};