How to determine the name of the active work environment?

#target photoshop
s2t = stringIDToTypeID;

var r = new ActionReference();
r.putProperty(s2t('property'), s2t('menuBarInfo'));
r.putEnumerated(s2t('application'), s2t('ordinal'), s2t('targetEnum'));
var mainMenu = executeActionGet(r).getObjectValue(s2t('menuBarInfo')).getList(s2t('submenu'))

var windowMenu = new ActionDescriptor()
for (var i = 0; i < mainMenu.count; i++) {
    if (mainMenu.getObjectValue(i).getString(s2t('title')) == localize('$$$/Menu/Window')) {
        var windowMenu = mainMenu.getObjectValue(i).getList(s2t('submenu'))
        break;
    }
}

var workspaceMenu = new ActionDescriptor()
for (var i = 0; i < windowMenu.count; i++) {
    if (windowMenu.getObjectValue(i).getString(s2t('title')) == localize('$$$/Menu/Window/ProjectWorkSpace')) {
        workspaceMenu = windowMenu.getObjectValue(i).getList(s2t('submenu'))
        break;
    }
}

for (var i = 0; i < workspaceMenu.count; i++) {
    if (workspaceMenu.getObjectValue(i).getBoolean(s2t('checked'))) {
        alert('current workpace: ' + workspaceMenu.getObjectValue(i).getString(s2t('title')))
    }
}

* if you switch the workspace and immediately run the script, it will show that the workspace has not changed (although it is not). Apparently Photoshop does not update the menuBarInfo descriptor until the user re-selects any menu item.

you can also use event notifications to track when the workspace is switched and save its name for future use (before first run the code, you need save it to a file, since the event listener will start it every time the workspace is changed)

#target photoshop
var s2t = stringIDToTypeID,
    t2s = typeIDToStringID,
    UUID = 'bf7064f7-eee2-4ac2-a639-5c3832469b43';

try {
    var target = t2s(arguments[0].getReference(s2t('null')).getDesiredClass())
    if (target == 'workspace') {
        var d = new ActionDescriptor();
        d.putString(s2t('workspace'), arguments[0].getReference(s2t('null')).getName())
        app.putCustomOptions(UUID, d)
    }
} catch (e) {
    app.notifiersEnabled = true
    var f = File($.fileName),
        deleted;
    for (var i = 0; i < app.notifiers.length; i++) {
        var ntf = app.notifiers[i]
        if (ntf.eventFile.name == f.name) { ntf.remove(); i--; deleted = true }
    }

    if (deleted) {
        alert('event listening disabled!')
    } else {
        alert('event listening enabled!')

        app.notifiers.add('slct', f)
        var r = new ActionReference();
        r.putProperty(s2t('property'), s2t('menuBarInfo'));
        r.putEnumerated(s2t('application'), s2t('ordinal'), s2t('targetEnum'));
        var mainMenu = executeActionGet(r).getObjectValue(s2t('menuBarInfo')).getList(s2t('submenu'))

        var windowMenu = new ActionDescriptor()

        for (var i = 0; i < mainMenu.count; i++) {
            if (mainMenu.getObjectValue(i).getString(s2t('title')) == localize('$$$/Menu/Window')) {
                var windowMenu = mainMenu.getObjectValue(i).getList(s2t('submenu'))
                break;
            }
        }

        var workspaceMenu = new ActionDescriptor()
        for (var i = 0; i < windowMenu.count; i++) {
            if (windowMenu.getObjectValue(i).getString(s2t('title')) == localize('$$$/Menu/Window/ProjectWorkSpace')) {
                workspaceMenu = windowMenu.getObjectValue(i).getList(s2t('submenu'))
                break;
            }
        }

        for (var i = 0; i < workspaceMenu.count; i++) {
            if (workspaceMenu.getObjectValue(i).getBoolean(s2t('checked'))) {
                var d = new ActionDescriptor();
                d.putString(s2t('workspace'), workspaceMenu.getObjectValue(i).getString(s2t('title')))
                app.putCustomOptions(UUID, d)
                break;
            }
        }
    }
}

In this case, you can get the name of the current workspace at any time (while event listener enabled) using the code:

var s2t = stringIDToTypeID,
    UUID = 'bf7064f7-eee2-4ac2-a639-5c3832469b43';
try {var d = app.getCustomOptions (UUID)} catch (e) {}
if (d) alert ('current workspace: ' + d.getString (s2t('workspace')))