Sublime Text 3: Build minified CSS file (with autoprefixer) and JS minified file on save (paths for Windows).

MakeOnSave.py

import sublime, sublime_plugin, os

class MakeOnSave(sublime_plugin.EventListener):
	def on_post_save(self, view):
		if view.file_name().endswith('.js'):
			folder_name, file_name = os.path.split(view.file_name())
			file_name, file_ext = file_name.split('.')
			view.window().run_command('exec', {
				'cmd': ['node', os.environ['APPDATA'] + '\\npm\\node_modules\\minifier\\index.js', '--no-comments', file_name+'.js', '-o', file_name+'.min.js'],
				'working_dir': folder_name
			})
			sublime.status_message(file_name + ' saved.')
		if view.file_name().endswith('.less'):
			folder_name, file_name = os.path.split(view.file_name())
			file_name, file_ext = file_name.split('.')
			view.window().run_command('exec', {
				'cmd': ['node', os.environ['APPDATA'] + '\\npm\\node_modules\\less\\bin\\lessc', '-x', file_name+'.less', file_name+'.min.without.autoprefixer.css'],
				'working_dir': folder_name
			})
			view.window().run_command('exec', {
				'cmd': ['node', os.environ['APPDATA'] + '\\npm\\node_modules\\autoprefixer\\autoprefixer', file_name+'.min.without.autoprefixer.css', '-o', file_name+'.min.css'],
				'working_dir': folder_name
			})
			sublime.status_message(file_name + ' saved.')