webpack.config.js

var webpack = require('webpack')

module.exports = {
    mode: "development",

    watch: true,

    // Enable sourcemaps for debugging webpack's output.
    devtool: "source-map",

    resolve: {
        // Add '.ts' and '.tsx' as resolvable extensions.
        extensions: [".ts", ".tsx", ".js", ".json"],
    },

    plugins: [
        new webpack.IgnorePlugin(/\.\/locale$/)
    ],

    module: {
        rules: [
            {
                test: /\.ts(x?)$/,
                exclude: /node_modules/,
                use: [
                    {
                        loader: "ts-loader"
                    }
                ]
            },
            // All output '.js' files will have any sourcemaps re-processed by 'source-map-loader'.
            {
                enforce: "pre",
                test: /\.js$/,
                loader: "source-map-loader"
            },
            {
                test: /\.s[ac]ss$/i,
                use: [
                  // Creates `style` nodes from JS strings
                  'style-loader',
                  // Translates CSS into CommonJS
                  'css-loader',
                  // Compiles Sass to CSS
                  'sass-loader',
                ],
              },
        ]
    },

    // When import * asing a module whose path matches one of the following, just
    // assume a corresponding global variable exists and use that instead.
    // This is import * asant because it allows us to avoid bundling all of our
    // dependencies, which allows browsers to cache those libraries between builds.
    externals: {
        "react": "React",
        "react-dom": "ReactDOM"
    }
}