Debugging Folder Actions Handlers

[alldritt (Mark Alldritt)]

Folder Actions Debugging

This article describes how to debug Folder Actions handlers using Script Debugger 8.

I’ve had a couple of support emails recently on this topic so I’m documenting it here for everyone.

Background

Before macOS Big Sur, Script Debugger was able to debug Folder Actions scripts as they ran using a feature called External Debugging. Security changes introduced in macOS Big Sur rendered the External Debugging feature inoperable. With the release of Script Debugger 8, we removed External Debugging entirely.

Simulation

The alternative is to use Script Debugger’s ability to simulate Folder Actions events and debug your scripts directly within Script Debugger.

Script Debugger’s Execute, Trace, Step Over and Step Info menu commands have submenus where you can select an AppleEvent to simulate. In the case of Folder Actions scripts, you can use any of the items in the Folder Actions submenu:

The items in the Folder Actions submenu are enabled if corresponding handlers exist in your script.

Depending on the event you select, Script Debugger may prompt you to locate the folder or file that is the subject of the event.

NOTE: My previous answer for this issue is obsolete:

How to debug a Folder Action Script

Hi everybody. I´m writing a script about adding items to my downloads folder to automate a workflow. The script is located at the Folder Action Scripts folder insider the Library folder of the disk, and It is attached to the downloads folder and “it works”. What happens is that I have difficult problems to debug it because when the script runs I can´t see where´s the problem in Script Debugger. I mean, I can put dozens of “display notification” to find out where the problem is but maybe there…

[Piyomaru]

I found the existence of “moving folder window for” event handler in Folder action script’s document.

Folder Actions Reference

It seems not working for a long time. SD has no “moving folder window for” debugging menu item.

Is “moving folder window for” event handler not working for a long time ?

[alldritt (Mark Alldritt)]

This event, as far as I know, has never worked. The documentation for the moving folder window for event handler is marked as Not currently available.

This is why we don’t offer a debugging facility for this event. If you wanted to, you could define a handler for this event and then create an on run test rig to invoke the handler with known inputs.

[Piyomaru]

Yes. You’re right. I wanted to know the acknowledge about this events not work.
Thank you!