SQLite return codes in JS V8

The open method does not return anything in js V8.

For example:

var sql = new SQLite();

let rtn = sql.open(db_name, 1, 1);

post("Open = " + rtn + "\n");

rtn is always null, whether or not the db exists.

If the db file does not exist, the error "v8jssqlite - Database file does not exist" displays in the console.

How can the error be seen within the js?