Gulp file with watch and build that use parcel as the bundler (WEB)

gulpfile.js

const gulp = require('gulp');
const notifier = require('node-notifier');
const parcel = require('parcel-bundler');
const shell = require('shelljs');

function notifyError(err) {
    notifier.notify({
        title: 'Gulp detect an error',
        message: 'Something broke! Please check console for logs!'
    });
}

function getBaseOptions(isProduction) {
    //we need to set the env because some plugins may depend on it
    process.env.NODE_ENV = (isProduction) ? 'production' : 'dev';

    return {
        entryFiles: ['./frontend/index.html'],
        outDir: './dist',
        publicUrl: '/',
        minify: isProduction,
        hmr: false,
        watch: !isProduction,
        plugins: []
    }
}

function cleanDistFolder(config) {
    shell.rm('-rf', config.outDir);
}

function getBundler(config) {
    var bundler = new parcel(config.entryFiles, config);
    bundler.on('buildError', error => {
        notifyError(error);
    });

    //customize the watch messages so they are easier to read
    if (config.watch) {
        bundler.on('buildStart', () => {
            console.log('\x1b[2J');
            console.log('\x1b[0f');
            console.log('Building...');
        });
    }

    //parcel when used as a API does not auto-discover the
    //plugins, so we must initialize the plugins manually
    //https://github.com/parcel-bundler/parcel/issues/3181
    if (config.plugins & config.plugins.length) {
        for (var i = 0; i < config.plugins.length; i++) {
            var plugin = config.plugins[i];
            plugin(bundler);
        }
    }

    return bundler;
}

function watch() {
    var config = getBaseOptions(false);
    cleanDistFolder(config);

    var bundler = getBundler(config);
    bundler.bundle();
}

async function build(cb) {
    var config = getBaseOptions(true);
    cleanDistFolder(config);

    var bundler = getBundler(config);
    await bundler.bundle();
    cb();
}

gulp.task('default', gulp.parallel(build));
gulp.task(build);
gulp.task(watch);