I'm getting this error while compiling the code node index.

Invalid schema configuration: `undefined` is not a valid type within the array `location`.

When I add this to the Joi validation schema, I get the error.

joi.array().items(joi.array().items(joi.number().integer())).default([]),

The array that I want to validate,

{
  // other fields..
  location: [[1,32,145], [0,1,null]],
  // other field 
}

I have tried other iterations to figure out what causes the error.

joi.array().items().default([]) // No error
joi.array().items(joi.number().integer()) // No error
joi.array().items(joi.array().items()) // This caused error 

I think adding an array inside an array is causing the error.

IMP NOTE: Using schema like this, and error around this.

new mongoose.Schema(joigoose.convert(PSS), { _id: false, versionKey: false })

I have manually added the array inside an array in MongoDB Document, which means this error is with mongoose, as joi allows array inside an array.