Tern & Google Apps Script support - angelozerr/tern.java GitHub Wiki
tern-gas provides the gas tern plugin which adds a support for Google Apps Script.
This support provides completion, hyperlink, text hover and validation for Google Apps Script framework.
After installing and converting your project as Tern Project, go at Tern project property, click on Tern / Modules item and select the gas tern plugin :
After that you can benefit with Google Apps Script completion :