rollup.config.js

import svelte from "rollup-plugin-svelte";
import commonjs from "@rollup/plugin-commonjs";
import resolve from "@rollup/plugin-node-resolve";
import { terser } from "rollup-plugin-terser";
import sveltePreprocess from "svelte-preprocess";
import typescript from "@rollup/plugin-typescript";
import fs from "fs";
import path from "path";
import replace from "@rollup/plugin-replace";

const production = !process.env.ROLLUP_WATCH;
const network = process.env.NETWORK || "dev";
const targetWeblets = process.env.TARGET_WEBLETS;

/**
 *
 * @param { {
 * 	src: string,
 * 	outdir: string,
 * 	element?: boolean,
 * 	keepCss?: boolean
 * } } options
 */
function build(options) {
  options = {
    element: false,
    keepCss: false,
    ...options,
  };

  const configs = {
    input: options.src, // 'src/main.ts',
    output: {
      sourcemap: false,
      format: "iife",
      name: "app",
      file: options.outdir, // 'public/build/bundle.js'
    },
    plugins: [
      svelte({
        preprocess: sveltePreprocess({ sourceMap: !production }),
        compilerOptions: {
          dev: !production,
          customElement: true,
        },
      }),
      resolve({
        browser: true,
        dedupe: ["svelte"],
      }),
      commonjs(),
      typescript({
        sourceMap: !production,
        inlineSources: !production,
      }),
      production && terser(),
      replace({
        preventAssignment: true,
        values: {
          "process.env.NETWORK": `"${network}"`,
          "process.env.VERSION": `"${process.env.VERSION || "No version to show"}"`,
        },
      }),
    ],
    watch: {
      clearScreen: false,
    },
  };

  return configs;
}

function buildElements() {
  const dir = path.join(__dirname, "src", "elements");
  const outDir = `.build/build/elements/`;
  let files = fs.readdirSync(dir);
  if (targetWeblets) {
    files = targetWeblets.split(" ");
  }
  return files.map(f => {
    const name = f.replace(".wc.svelte", "").toLocaleLowerCase();
    return build({
      src: `src/elements/${f}/index.ts`,
      outdir: outDir + `${name}.wc.js`,
      element: true,
      keepCss: true,
    });
  });
}

export default buildElements();