simple setup - am i missing sth?

[nerdess]

i am trying to get the plugin to transpile the code inside public/bundle.js from ES6 to ES5 but it has no effect, the code is still ES6.

my rollup.config.js is quite simple:

import svelte from 'rollup-plugin-svelte';
import resolve from 'rollup-plugin-node-resolve';
import commonjs from 'rollup-plugin-commonjs';
import livereload from 'rollup-plugin-livereload';
import { terser } from 'rollup-plugin-terser';
import rollup_start_dev from './rollup_start_dev';
import css from 'rollup-plugin-css-only';
import json from 'rollup-plugin-json';
import autoPreprocess from 'svelte-preprocess';
import babel from 'rollup-plugin-babel';

const production = !process.env.ROLLUP_WATCH;

export default {
    input: 'src/main.js',
    output: {
        sourcemap: true,
        format: 'iife',
        name: 'app',
        file: 'public/bundle.js'
    },
    plugins: [
        svelte({
            dev: !production,
            css: css => {
                css.write('public/bundle.css');
            },
            preprocess: autoPreprocess()
        }),
        json(),
        css({output:'public/libs.css'}),
        resolve({
            browser: true,
            dedupe: importee => importee === 'svelte' || importee.startsWith('svelte/')
        }),
        babel({
            babelrc: false,
            presets: [['@babel/env', { modules: false }]],
            exclude: 'node_modules/**'
        }),       
        commonjs(),

        !production && rollup_start_dev,

        !production && livereload('public'),

        production && terser(),

    ],
    watch: {
        clearScreen: false
    }
};

am i missing sth? e.g. is a .babelsrc with additional configuration required?

[nerdess]

fixed it now using this guide: https://blog.az.sg/posts/svelte-and-ie11/