Question

How can I check if the remove-method of a Mongoose model really has removed something?

MyModel.remove({_id: myId}, function(err, entry) {
  if(entry == null) next(new Error("ID was not found."));    // this doesn't work
}

Can I check how many documents were removed?

In the Mongo-Documentation kristina1 write in a comment:

If you call db.runCommand({getLastError:1}) after a remove and the “n” field will tell you how many documents were deleted.

But I don’t know how to do this with Mongoose.

Answer 1

Mongoose < 4, MongoDB < 3

The second parameter to the remove callback is a number containing the number of documents removed.

MyModel.remove({_id: myId}, function(err, numberRemoved) {
  if(numberRemoved === 0) next(new Error("ID was not found."));
}

Mongoose 4.x, MongoDB 3.x

The second parameter passed to the remove callback is now an object with the result.n field indicating the count of removed documents:

MyModel.remove({_id: myId}, function(err, obj) {
  if(obj.result.n === 0) next(new Error("ID was not found."));
}