index.js

const webpack = require('webpack');
const merge = require('webpack-merge');
const HtmlWebpackInlineSourcePlugin = require('html-webpack-inline-source-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const path = require('path');

// Default Webpack configuration
// @see: https://webpack.js.org/configuration/
const baseConfig = {
    entry: {
        ui: './src/ui.tsx', // The entry point for your UI code
        code: './src/code.tsx' // The entry point for your plugin code
    },

    module: {
        rules: [
            // Converts TypeScript code to JavaScript
            { test: /\.tsx?$/, use: 'ts-loader', exclude: /node_modules/ },

            // Enables including CSS by doing "import './file.css'" in your TypeScript code
            { test: /\.css$/, loader: [{ loader: 'style-loader' }, { loader: 'css-loader' }] },

            // Allows you to use "<%= require('./file.svg') %>" in your HTML code to get a data URI
            { test: /\.(png|jpg|gif|webp|zip)$/, loader: [{ loader: 'url-loader' }] },

            { test: /\.svg$/, loader: [{ loader: 'svg-inline-loader' }] }
        ]
    },

    // Webpack tries these extensions for you if you omit the extension like "import './file'"
    resolve: {
      extensions: ['.figma.tsx', '.figma.ts', 'figma.jsx', '.figma.js', '.tsx', '.ts', '.jsx', '.js']
    },

    output: {
        filename: '[name].js',
        path: path.resolve(process.cwd(), 'dist') // Compile into a folder called "dist"
    },

    plugins: [
        new HtmlWebpackPlugin({
            template: './src/ui.html',
            filename: 'ui.html',
            inlineSource: '.(js)$',
            chunks: ['ui']
        }),
        new HtmlWebpackInlineSourcePlugin()
    ]
};

// Options that should only be applied in development builds:
const developmentConfig = {
    mode: 'development',

    // This is necessary because Figma's 'eval' works differently than normal eval
    devtool: 'inline-source-map',
};

// Options that should only be applied in production builds:
const productionConfig = {
    mode: 'production',

    // This is necessary because Figma's 'eval' works differently than normal eval
    devtool: false,
};

// Export a `configure()` function for applications to
// import & extend in their `webpack.config.js` files.
module.exports = options => env => {
    const isProduction = env === 'production';
    const environmentConfig = isProduction ? productionConfig : developmentConfig;

    // Merge our base config, environment overrides, and per-app overrides.
    return merge(baseConfig, environmentConfig, options);
};