The VS Code Debugger

Since The ExtendScript Toolkit has been deprecated by Adobe (in part due to MacOS dropping support for 32-bit apps), the official method of debugging Extendscript is by using VS Code with the Adobe Extendscript extension.

It’s semi-buggy, generally unreliable, and seems to be meant for self-contained instant-run scripts (as opposed to ScriptUI panels), but it can be helpful in some cases.

The docs here are currently in progress and are ever-evolving; contributions are encouraged and welcome!