I created an API for my project, but I got an error on one of the endpoints that I can't fix.

const fullOrdersForService = service.totalOrders const updatedFullOrdersForService = fullOrdersForService + 1 const updateService = await Service.findOneAndUpdate({_id:serviceId}, { totalOrders: updatedFullOrdersForService },{new:true})

Definitely in the above code, I checked the type ofservice.totalOrders, the output is number, andservice.totalOrderscomes from a schema, so there is no possibility of it being typed Change to string or NaN. I checked if it is NaN and the result is also false, it is not NaN. I'm still wondering how this error occurs. But the following error occurred.

messageFormat: undefined, stringValue: '"NaN"', kind: 'Number', value: NaN, path: 'totalOrders', reason: AssertionError [ERR_ASSERTION]: The expression evaluated to a falsy value: assert.ok(!isNaN(val))

The schema for myService.totalOrderscan be seen below.

totalOrders:{ type:Number, required:true, default:0 }

My schema forSeller.totalOrderscan be seen below.

totalOrders:{ type:Number, required:true, default:0 }

const fullOrdersForService = service.totalOrders const updatedFullOrdersForService = fullOrdersForService + 1 const updateService = await Service.findOneAndUpdate({_id:serviceId}, { totalOrders: updatedFullOrdersForService },{new:true})

I just tried this code and got the error I mentioned above.