Array validation not working for PATCH in mongoose - validation

Question

This is my mongoose schema. but when i send PATCH req from client. the options (array) validation not work. but others field's validation work.
I search in online but dont get the problem. How can I slove it. Thank you.
const optionsValidator = function (options) {
console.log("Validating options...");
const MinLength = 2;
const MaxLength = 6;
const MCQCode = 0;
// checking options are required or not for the question;
if (this.questionType !== MCQCode) {
throw new Error("Options are required only for MCQ");
}
if (options.length < MinLength) {
throw new Error(`At least ${MinLength} options are required`);
}
if (options.length > MaxLength) {
throw new Error(`Maximum ${MaxLength} options can be created`);
}
// make options lower case before checking uniqueness of the options
const lowerOptions = options.map((option) => option.toLowerCase());
if (lowerOptions.length !== new Set(lowerOptions).size) {
throw new Error("Options are not unique");
}
// options are validated
return true;
};
const questionSchema = new Schema({
quesId: { type: String, required: [true, "Id_required"] },
title: { type: String, required: [true, "title_required"] },
questionType: {
type: Number,
default: 0,
},
options: {
type: [String],
default: undefined,
required: function () {
return this.questionType === 0 && !this.options;
},
validate: {
validator: optionsValidator,
message: (props) => props.reason.message,
},
},
});
const updatedData = { ...questionData };
let optionsData;
if (updatedData.options) {
data = await Question.findById(id);
optionsData = {
$push: { options: { $each: updatedData.options } },
};
delete updatedData.options;
}
exports.patchQuestion = async (id, questionData) => {
return (result = await Question.findOneAndUpdate(
{ _id: id },
{ ...optionsData, $set: updatedData },
{ new: true, runValidators: true }
));
}
The is the PATCH request send form client.
{ "options": ["A","A"] }