gulpfile.babel.js

import gulp from 'gulp';
import browserify from 'browserify';
import babelify from 'babelify';
import source from 'vinyl-source-stream';

gulp.task('default', () => {
        console.log("default log");
});

gulp.task('build', () => {
        browserify('./src/app.jsx', { debug: true })
                .transform(babelify)
                .bundle()
                .on('error', (err) => {
                        console.debug("Error: " + err.message);
                })
                .pipe(source('bundle.js'))
                .pipe(gulp.dest('./built'))
});

gulp.task('default', ['build']);