rollup.config.js

import svelte from 'rollup-plugin-svelte'
import alias from '@rollup/plugin-alias'
import resolve from '@rollup/plugin-node-resolve'
import commonjs from '@rollup/plugin-commonjs'
import autoPreprocess from 'svelte-preprocess'
import livereload from 'rollup-plugin-livereload'
import { terser } from 'rollup-plugin-terser'
import replace from '@rollup/plugin-replace'
import { config } from 'dotenv'

const production = !process.env.ROLLUP_WATCH
const { parsed: { JEXIA_PROJECT_ID, JEXIA_API_KEY, JEXIA_API_SECRET } } = config()

export default {
  input: 'src/main.js',
  output: {
    sourcemap: true,
    format: 'iife',
    name: 'app',
    file: 'public/build/bundle.js'
  },
  plugins: [
    replace({
      exclude: 'node_modules/**',
      include: 'src/env.js',
      'jexia-project-id': JEXIA_PROJECT_ID,
      'jexia-key': JEXIA_API_KEY,
      'jexia-secret': JEXIA_API_SECRET
    }),
    alias({
      entries: [
        { find: '@ui', replacement: 'src/UI' },
        { find: '@meetups', replacement: 'src/Meetups' },
        { find: '@helpers', replacement: 'src/helpers' }
      ]
    }),
    svelte({
      // enable run-time checks when not in production
      dev: !production,
      // we'll extract any component CSS out into
      // a separate file — better for performance
      css: css => {
        css.write('public/build/bundle.css')
      },
      preprocess: autoPreprocess()
    }),

    // 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: importee => importee === 'svelte' || importee.startsWith('svelte/')
    }),
    commonjs(),

    // 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
  }
}

function serve () {
  let started = false

  return {
    writeBundle () {
      if (!started) {
        started = true

        require('child_process').spawn('npm', ['run', 'start', '--', '--dev'], {
          stdio: ['ignore', 'inherit', 'inherit'],
          shell: true
        })
      }
    }
  }
}