I need to delete all snapshots and layer comps by a script

// 2017, use it at your own risk;

#target photoshop

if (app.documents.length > 0) {

try {

var myDocument = app.activeDocument;

myDocument.layerComps.removeAll();

var theStates = myDocument.historyStates;

for (m = theStates.length - 1; m >=0; m--) {

if (theStates.snapshot == true) {

  myDocument.activeHistoryState = theStates;

  delHist()

  }

};

} catch (e) {}

};

function delHist() {

var desc20 = new ActionDescriptor();

var ref23 = new ActionReference();

ref23.putProperty( charIDToTypeID('HstS'), charIDToTypeID('CrnH') );

desc20.putReference( charIDToTypeID('null'), ref23 );

executeAction( charIDToTypeID('Dlt '), desc20, DialogModes.NO );

};