> Does this work with JSC REPL for trying things out?
It does not: just tried it. The document lists the places it will work:
> The component can be used from Script Editor, the global Script Menu, in the Run JavaScript Automator Action, applets/droplets, the osascript command-line tool, the NSUserScriptTask API, and everywhere else other OSA components, such as AppleScript, can be used. This includes Mail Rules, Folder Actions, Address Book Plugins, Calendar Alarms, and Message Triggers.
It doesn't have a proper REPL mode, but the closest thing to what you're looking for is probably osascript.
It does not: just tried it. The document lists the places it will work:
> The component can be used from Script Editor, the global Script Menu, in the Run JavaScript Automator Action, applets/droplets, the osascript command-line tool, the NSUserScriptTask API, and everywhere else other OSA components, such as AppleScript, can be used. This includes Mail Rules, Folder Actions, Address Book Plugins, Calendar Alarms, and Message Triggers.
It doesn't have a proper REPL mode, but the closest thing to what you're looking for is probably osascript.