Catch error when using populate with mongoose - node.js

Question

I have the next model and route with mongoose:
In my colection I have some invalids id's to "cidade" field and this is why I am getting the error showing below.
The error happens in the line:
.populate('cidade')
Is there a way to execute my router(code is below) in:
router.get('/:id',function(req,res,next){ .....
without stop on that error?
If an invalid "id" is found, I´d just like to ignore it and proceed to next.
My collections are too big and can have some invalids "ids" to "cidade" field.
//error
angular.js:14328 Possibly unhandled rejection: {"data":{"message":"Cast to ObjectId failed for value \"Ararendá\" at path \"_id\" for model \"Cidade\"","name":"CastError","stringValue":"\"Ararendá\"","kind":"ObjectId","value":"Ararendá","path":"_id"},"status":500,"config":
//models and route
//cidade
cidadesSchema = new mongoose.Schema({
uf: {type: String, unique:true},
cidade: {type: String, unique:true}
});
module.exports = mongoose.model('Cidade', cidadesSchema,'cidades' );
//profiss
var profissionaisSchema = new mongoose.Schema({
nome: {type: String, unique:true},
cidade: {type:mongoose.Schema.Types.ObjectId, ref:'Cidade'},
estado: {type:mongoose.Schema.Types.ObjectId, ref:'Estado'},
cep: {type: String},
});
module.exports = mongoose.model('Profissional', profissionaisSchema,'profissionais' );
//route
const callback=function(err,data,res){
if (err) return res.status(500).json(err);
return res.status(200).send(data);
}
router.get('/:id',function(req,res,next){
const query=req.params.id;
Profissional.findById(query).populate('profissao')
.populate('cidade')
.exec( (err,data) => {
callback(err,data,res)
});
});

Answer 1

I don't think you can tell Mongoose to just ignore those errors and keep going, so you're going to have to implement the population yourself (which should be relatively easy because you're using findById which would only yield, at most, one document).
Here's some (untested) code:
Profissional.findById(query).populate('profissao').exec( (err, profi) => {
if (err) {
return res.status(500).json(err);
} else if (! profi || ! /^[a-f0-9]{24}$/i.test(profi.cidade)) {
return res.status(200).send(profi);
}
Cidade.findById(profi.cidade).exec((err, cidade) => {
if (err) {
return res.status(500).json(err);
}
profi.cidade = cidade;
return res.status(200).send(profi);
});
});
If the cidade property looks like a valid ObjectId, it will run a query to retrieve it, otherwise it won't bother.