rollup.config.js

import resolve from "@rollup/plugin-node-resolve";
import typescript from "@rollup/plugin-typescript";
import execute from "rollup-plugin-execute";
import svelte from "rollup-plugin-svelte";
import sveltePreprocess from "svelte-preprocess";
import pkg from "./package.json";

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: [
					// we only want to run this once, so we'll just make it part of this output's plugins
					execute([
						"tsc --outDir ./dist --declaration",
						"node scripts/preprocess.js",
					]),
				],
			},
		],
		plugins: [
			svelte({
				preprocess: sveltePreprocess(),
			}),
			resolve(),
			typescript(),
		],
	},
];