model.test.js

    var db = start();
    var schema = new Schema({ s: [String] });
    var S = db.model('arrayWithUndefined', schema);
    var s = new S({ s: ['hi', undefined] }); // no error
    console.error(s.s); // []
    console.error(s._saveError.message); // Cast to non_object_property_load failed for value "hi,"