Get security and peace of mind by backing up your Google Apps Script files to Google Docs and trigger for continuous backup.
We’ve featured a couple of methods for restoring Google Apps Script code in Pulse, but most of these rely on recovering a deployed version of the script. Stéphane Giron wields his Apps Script hammer and skilfully demonstrates how you can use Google Docs and it’s built-in version history as a way of keeping a backup copy of your code.
Source: Quick and not so Dirty backup solution for Google Apps Script Code
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Member of Google Developers Experts Program for Google Workspace (Google Apps Script) and interested in supporting Google Workspace Devs.