package_build.py

import os
import sublime
import sublime_plugin


def get_npm_scripts(chosen_directory):
	""" Gets the list of npm scripts defined in the package.json

	Args:
		chosen_directory (str) : The absolute path of the chosen directory.

	Returns:
		npm_scripts (list)     : The list of npm scripts defined in package.json
	"""
	package_json_path = os.path.join(chosen_directory, "package.json")
	with open(package_json_path) as package_json:
		json_data = sublime.decode_value(package_json.read())
		npm_scripts = [key for key in json_data["scripts"]]
	return npm_scripts


class RunNpmScriptsCommand(sublime_plugin.WindowCommand):
	""" Lists all npm projects & then lists all npm scripts. Selecting one of them executes the said npm script.
	"""

	def run(self, use_terminus=False):
		"""Invoked when the command is run and shows a list of folders.

		Args:
			None

		Returns:
			None
		"""
		is_terminus = use_terminus
		global is_terminus
		npm_projects = [x for x in self.window.folders() if os.path.isfile(os.path.join(x, "package.json"))]
		if len(npm_projects) == 0:
			self.window.status_message("No folder in the side bar is an npm project")
			return
		elif len(npm_projects) == 1:
			self.show_npm_scripts(npm_projects, 0)
			return
		self.window.show_quick_panel(npm_projects, lambda id: self.show_npm_scripts(npm_projects, id))


	def show_npm_scripts(self, npm_projects, id):
		"""Shows the npm scripts defined in the package.json of the chosen directory.

		Args:
			npm_projects (list) : List of all folders in side bar that are npm projects.
			id (int)            : The id of the selected folder.

		Returns:
			None
		"""
		chosen_directory = npm_projects[id]
		if id >= 0:
			npm_scripts = get_npm_scripts(chosen_directory)
			if len(npm_scripts) == 0:
				self.window.status_message("No npm scripts in package.json")
			else:
				self.window.show_quick_panel(npm_scripts, lambda id: self.run_build_system(npm_scripts, chosen_directory, id))
		else:
			self.window.status_message("No directory chosen")


	def run_build_system(self, npm_scripts, chosen_directory, id):
		"""Runs the exec command & passes it on some parameters for running the chosen npm script.

		Args:
			npm_scripts (list)     : A list of npm scripts defined in the package.json of the chosen directory.
			chosen_directory (str) : The absolute path of the selected directory
			id (int)               : The id of the npm script selected.

		Returns:
			None
		"""
		if id >= 0:
			is_terminus_installed = "Terminus" in sublime.load_settings("Package Control.sublime-settings").get("installed_packages")
			target = "terminus_exec" if (is_terminus and is_terminus_installed) else "exec"
			self.window.run_command(target, {
				"shell_cmd": "npm run {}".format(npm_scripts[id]),
				"working_dir": chosen_directory
			})
		else:
			self.window.status_message("No npm script selected")

Thanks :-)