webpack.config.js

const path = require("path")
const webpack = require("webpack")
const HtmlWebpackPlugin = require("html-webpack-plugin")
const CleanWebpackPlugin = require("clean-webpack-plugin")

if (process.env.NODE_ENV !== "production") {
  require("dotenv").config()
}

const envVarsToInject = ["NODE_ENV", "GRAPHQL_API_URL"]

module.exports = {
  mode: process.env.NODE_ENV || "development",
  entry: "./src/index.js",
  output: {
    filename: "bundle.js",
    path: path.resolve(__dirname, "dist"),
    publicPath: "/"
  },
  plugins: [
    new CleanWebpackPlugin(["dist"]),
    new HtmlWebpackPlugin({
      template: "src/index.html"
    }),
    new webpack.DefinePlugin({
      "process.env": envVarsToInject.reduce(
        (acc, key) => ({
          ...acc,
          [key]: JSON.stringify(process.env[key])
        }),
        {}
      )
    })
  ],
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: {
          loader: "babel-loader"
        }
      },
      {
        test: /\.(png|jpg|gif|svg)$/,
        use: [
          {
            loader: "file-loader"
          }
        ]
      },
      {
        test: /\.css$/,
        use: ["style-loader", "css-loader"]
      }
    ]
  },
  devServer: {
    contentBase: "./dist",
    historyApiFallback: true
  }
}