rollup.config.js

import svelte from 'rollup-plugin-svelte';
import commonjs from '@rollup/plugin-commonjs';
import resolve from '@rollup/plugin-node-resolve';
import livereload from 'rollup-plugin-livereload';
import { terser } from 'rollup-plugin-terser';
import sveltePreprocess from 'svelte-preprocess';
import copy from 'rollup-plugin-copy-watch';
//import assetsPreprocessor from 'svelte-assets-preprocessor'
import typescript from '@rollup/plugin-typescript';
import css from 'rollup-plugin-css-only';
import json from '@rollup/plugin-json';
import url from '@rollup/plugin-url';
import { svelteSVG } from 'rollup-plugin-svelte-svg';
import replace from '@rollup/plugin-replace';
import { markdown } from 'svelte-preprocess-markdown';
// import partsJSON from '../data/parts.json' assert { type: 'json' };
import { importAssertionsPlugin } from 'rollup-plugin-import-assert';
import { importAssertions } from 'acorn-import-assertions';

const production = !process.env.ROLLUP_WATCH;

function serve() {
  let server;

  function toExit() {
    if (server) server.kill(0);
  }

  return {
    writeBundle() {
      if (server) return;
      server = require('child_process').spawn('npm', ['run', 'start-by-rollup', '--', '--dev'], {
        stdio: ['ignore', 'inherit', 'inherit'],
        shell: true,
      });

      process.on('SIGTERM', toExit);
      process.on('exit', toExit);
    },
  };
}

export default {
  input: 'src/main.ts',
  output: {
    sourcemap: !production,
    format: 'iife',
    name: 'app',
    file: 'public/build/bundle.js',
  },
  external: ['react'],
  acornInjectPlugins: [importAssertions],
  plugins: [
    importAssertionsPlugin(),
    url({ destDir: 'public' }),
    json({
      // All JSON files will be parsed by default,
      // but you can also specifically include/exclude files
      include: 'data/**',
      exclude: ['node_modules/**'],

      // for tree-shaking, properties will be declared as
      // variables, using either `var` or `const`
      preferConst: true, // Default: false

      // specify indentation for the generated default export —
      // defaults to '\t'
      indent: '  ',

      // ignores indent and generates the smallest code
      compact: true, // Default: false

      // generate a named export for every property of the JSON object
      namedExports: true, // Default: true
    }),
    svelteSVG(),
    svelte({
      extensions: ['.svelte', '.md'],
      // 3. add markdown preprocessor
      preprocess: [
        // https://www.npmjs.com/package/svelte-assets-preprocessor
        // assetsPreprocessor({
        //     // only images
        //     exclude: [ (attr) => !/\.(png|svg|jpg|gif)$/.test(attr) ]
        // }),
        markdown(),
        sveltePreprocess({ sourceMap: !production }),
      ],
      compilerOptions: {
        // enable run-time checks when not in production
        dev: !production,
      },
      onwarn: (warning, handler) => {
        const { code, frame } = warning;
        if (code === 'css-unused-selector') return;
        handler(warning);
      },
    }),
    replace({
      preventAssignment: true,
      'process.env.NODE_ENV': JSON.stringify(production ? 'production' : 'development'),
    }),
    // we'll extract any component CSS out into
    // a separate file - better for performance
    css({ output: 'bundle.css' }),
    // If you have external dependencies installed from
    // npm, you'll most likely need these plugins. In
    // some cases you'll need additional configuration -
    // consult the documentation for details:
    // https://github.com/rollup/plugins/tree/master/packages/commonjs
    resolve({
      browser: true,
      dedupe: ['svelte'],
    }),
    commonjs(),
    typescript({
      sourceMap: !production,
      inlineSources: !production,
    }),

    !production &&
      copy({
        // the watch option is passed directly to Chokidar, so it can be a file,
        // dir, array or glob(s)
        watch: 'static',

        targets: [{ src: './data/all-products-history.json', dest: './public/data/' }],
      }),

    // In dev mode, call `npm run start` once
    // the bundle has been generated
    !production && serve(),

    // Watch the `public` directory and refresh the
    // browser on changes when not in production
    !production && livereload('public'),

    // If we're building for production (npm run build
    // instead of npm run dev), minify
    production && terser(),
  ],
  watch: {
    clearScreen: false,
  },
};