Add a method to copy a sheet with all data and formatting because there are no back-up or undo options for add-ins.
Since there is no way to cancel the changes made by an add-in, we need to provide users with backup options.
Renat, thank you for the feedback! This is in our product roadmap and we plan to implement the API in the near future. This will be available as part of the promise based API set.
As always, when the design draft is ready, we’ll present design for review under the open-spec branches of this repository: https://github.com/officedev/office-js-docs.
Office Extensibility Team
Would be very useful.