webpack is configured as follows

const HtmlWebpackPlugin = require("html-webpack-plugin");
const CleanWebpackPlugin = require("clean-webpack-plugin");
const ExtractTextPlugin = require("extract-text-webpack-plugin");
module.exports = {
    entry: {/*  */
        index: "./src/index/index.js",
        sally: "./src/sally/sally.js"
    },
    output: {
        path: __dirname + "/dist",
        filename: "[name].js"
    },
    devServer: {
        contentBase: __dirname + "/dist",
        host: "localhost",
        port: "8083",
        open: true,
    },
    module: {
        rules: [
          {
            test: /\.css$/,
            use: ExtractTextPlugin.extract({
                fallback: "style-loader",
                use: "css-loader"
              }),
          },
          {
            test: /\.(png|jpg|gif)$/i,
            use: ExtractTextPlugin.extract({
                fallback: "style-loader",
                use: "css-loader"
              })
          }
        ],
      },
    plugins: [
        new ExtractTextPlugin("index.css"),
        new CleanWebpackPlugin("./dist"),
        new HtmlWebpackPlugin({
            filename: "index.html",
            template: "./src/template.html",
            hash: true,
            // minify: {
            //     collapseWhitespace: true,
            // },
            title: "hi there~",
            chunks: ["index"]
        }),
        new HtmlWebpackPlugin({
            filename: "sally.html",
            template: "./src/template.html",
            hash: true,
            title: "hi there~",
            chunks: ["sally"]
        })
      ]

}/*  */

the file directory is as follows

unclosed string webpack4extract-text-webpack-plugin