webpack.config.js

const webpack = require('webpack');
const dotenv = require('dotenv');
const path = require('path');
const HtmlWebpackPlugin = require("html-webpack-plugin");

module.exports = () => {
  const env = dotenv.config().parsed;
  const envKeys = Object.keys(env).reduce((prev, next) => {
    prev[`process.env.${next}`] = JSON.stringify(env[next]);
    return prev;
  }, {});
  return {
    entry: "./src/index.js",
    output: {
      publicPath: "/",
      path: path.join(__dirname, "dist"),
      filename: "index_bundle.js"
    },
    devtool: 'source-map',
    module: {
      rules: [
        {
          test: /\.js$/,
          exclude: /node_modules/,
          use: {
            loader: "babel-loader"
          },
        },
        {
          test: /\.css$/,
          use: ["style-loader", "css-loader"]
        },
        {
          test: /\.svg$/,
          loader: 'svg-inline-loader'
        },
        { test: /\.(png|woff|woff2|eot|ttf|svg)$/, loader: 'url-loader?limit=100000' }
      ]
    },
    plugins: [
      new HtmlWebpackPlugin({
        template: "./src/index.html"
      }),
      new webpack.DefinePlugin(envKeys)
    ],
    devServer: {
      historyApiFallback: true
    }
  }
};