rollup.config.js

import resolve from "@rollup/plugin-node-resolve";
import babel from "rollup-plugin-babel";
import copy from "rollup-plugin-copy";
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.js",
    output: [
        {file: pkg.module, format: "es"},
        {file: pkg.main, format: "umd", name}
    ],
    plugins: [
        babel({
            presets: [
                [
                    "@babel/preset-env",
                    {
                        modules: false
                    }
                ]
            ]
        }),
        resolve(),
        copy({
            targets: [{src: "typings/index.d.ts", dest: "dist/"}]
        })
    ]
};