STILL IN EARLY DEV AND NOT TESTED, USE AT YOUR OWN RISK
Source code is here: https://github.com/lvl5hm/go-bundler/tree/src.
A bundler for javascript files with minimal config, written in golang.
Has built-in dev server, auto rebuild on file change and can build html templates along with js files.
All non-js files are copied to bundle folder and imported as urls.
Very fast so far :D
Install bundler
npm install --save-dev go-bundler
Run npm command
go-bundler
You will be prompted to answer a couple of questions to generate a config file. You will then be able to edit it manually in go-bundler-config.json