rollup.config.ts

import resolve from "@rollup/plugin-node-resolve";
import commonjs from "@rollup/plugin-commonjs";
import json from "@rollup/plugin-json";

import sourceMaps from "rollup-plugin-sourcemaps";
import typescript from "@wessberg/rollup-plugin-ts";

import camelCase from "camelcase";

import analyze from "rollup-plugin-analyzer";
import svelte from "rollup-plugin-svelte";
import { preprocess, createEnv, readConfigFile } from "@pyoner/svelte-ts-preprocess";

const production = !process.env.ROLLUP_WATCH;

const env = createEnv();
const compilerOptions = readConfigFile(env);
const opts = {
  env,
  compilerOptions: {
    ...compilerOptions,
    allowNonTsExtensions: true,
  },
};

const pkg = require("./package.json");

const libraryName = "svelte-form";

export default {
  input: `src/index.ts`,
  output: [
    { file: pkg.main, name: camelCase(libraryName), format: "umd", sourcemap: true },
    { file: pkg.module, format: "es", sourcemap: true },
  ],
  // Indicate here external modules you don't wanna include in your bundle (i.e.: 'lodash')
  external: [],
  watch: {
    include: "src/**",
  },
  plugins: [
    analyze({ summaryOnly: true }),
    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/bundle.css");
      },
      preprocess: preprocess(opts),
    }),
    // Allow json resolution
    json(),
    // Allow bundling cjs modules (unlike webpack, rollup doesn't understand cjs)
    commonjs(),
    // Allow node_modules resolution, so you can use 'external' to control
    // which external modules to include in the bundle
    // https://github.com/rollup/rollup-plugin-node-resolve#usage
    resolve(),
    // Compile TypeScript files
    typescript(),

    // Resolve source maps to the original source
    sourceMaps(),
  ],
};