How can I tell if a layer has a layer style by using a script?

If you use Google Search you can find code to do that on this site.  You will find code like this. Test if activeLayer has a layer effect.

alert(haslayerEffects());

function haslayerEffects()     {
    try {
        var d = new ActionDescriptor();
        var r = new ActionReference();
        r.putEnumerated(stringIDToTypeID("layer"), stringIDToTypeID("ordinal"), stringIDToTypeID("targetEnum"));
        var options = executeActionGet(r);  
        return options.hasKey(stringIDToTypeID("layerEffects"))
        }
    catch (e) {alert(e) }
}

I extracted that from script to remove all layer effects 

You often need to use Action manager code which I do not know how to code I can hack on the action manager code Adobe scriplistener plug-in records. However, for the executeActionGet  code required the get information I need to use search and find. It would be better if this web site search was useable.