webpack.config.js

const path = require("path");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const CopyWebpackPlugin = require("copy-webpack-plugin");

module.exports = (env, argv) => {
  const isDevelopment = argv.mode === "development";

  return {
    entry: {
      popup: "./src/popup/index.tsx",
      content: "./src/content/content.ts",
      background: "./src/background/background.ts"
    },
    output: {
      path: path.resolve(__dirname, "dist"),
      filename: "[name].js",
      clean: true
    },
    module: {
      rules: [
        {
          test: /\.(ts|tsx)$/,
          exclude: /node_modules/,
          use: {
            loader: "ts-loader",
            options: {
              transpileOnly: true
            }
          }
        },
        {
          test: /\.(js|jsx)$/,
          exclude: /node_modules/,
          use: {
            loader: "babel-loader",
            options: {
              presets: [
                "@babel/preset-env",
                "@babel/preset-react",
                "@babel/preset-typescript"
              ]
            }
          }
        },
        {
          test: /\.css$/,
          use: ["style-loader", "css-loader"]
        }
      ]
    },
    plugins: [
      new HtmlWebpackPlugin({
        template: "./src/popup/popup.html",
        filename: "popup.html",
        chunks: ["popup"]
      }),
      new CopyWebpackPlugin({
        patterns: [
          { from: "manifest.json", to: "manifest.json" },
          { from: "src/content/content.css", to: "content.css" },
          {
            from: "src/styles/output.css",
            to: "styles.css",
            noErrorOnMissing: true
          },
          { from: "icon16.png", to: "icon16.png" },
          { from: "icon48.png", to: "icon48.png" },
          { from: "icon128.png", to: "icon128.png" },
          { from: "src/assets", to: "assets", noErrorOnMissing: true }
        ]
      })
    ],
    resolve: {
      extensions: [".ts", ".tsx", ".js", ".jsx"]
    },
    mode: argv.mode || "development",
    devtool: isDevelopment ? "cheap-module-source-map" : false,
    watchOptions: isDevelopment
      ? {
          ignored: /node_modules/,
          poll: 1000
        }
      : undefined
  };
};