We are developing an Office add-in and face some issues when testing it on Excel for Mac.
We've added the following requirements to the manifest:
<Set Name="AddinCommands" />
From what we see, all the above requirement sets exist (e.g. The add-in commands are visible in the Excel ribbon), but when trying to call Office.context.document.getFileAsync we get an 'undefined'.
According to this https://dev.office.com/reference/add-ins/shared/document.getfileasync the Document.getFileAsync method is part of the File requirement set, which is not supported in Excel for Mac.
The root cause has been identified and a patch is scheduled to be applied to JS library on 9/14. I can update this thread once it is rolled out. Thanks
This is now fixed and is working for Mac platform. Thanks for your patience.