rollup.config.js

import resolve from "@rollup/plugin-node-resolve";
import commonjs from "@rollup/plugin-commonjs";
import typescript from "@rollup/plugin-typescript";
import svelte from "rollup-plugin-svelte";
import autoPreprocess from "svelte-preprocess";
import { terser } from "rollup-plugin-terser";

import pkg from "./package.json";

const production = !process.env.ROLLUP_WATCH;
const name = pkg.name
  .replace(/^(@\S+\/)?(svelte-)?(\S+)/, "$3")
  .replace(/^\w/, m => m.toUpperCase())
  .replace(/-\w/g, m => m[1].toUpperCase());

export default {
  input: "src/index.ts",
  output: [
    {
      file: pkg.module,
      format: "es",
      sourcemap: true,
    },
    {
      file: pkg.main,
      format: "umd",
      name,
      sourcemap: true,
    },
  ],
  plugins: [
    commonjs(),
    typescript({ sourceMap: true }),
    svelte({
      preprocess: autoPreprocess({ sourceMap: true }),
      compilerOptions: {
        dev: !production,
      },
      emitCss: false,
    }),
    resolve({
      browser: true,
      dedupe: ["svelte"],
    }),
    production && terser(),
  ],
  watch: {
    clearScreen: false,
  },
};