How do I return an error from a Meteor.call method inside another Meteor.call

Question

My meteor code goes a couple Meteor.call methods deep at some points. If I have an error in the 2nd layer and I want to throw that meteor error back to the client side how can I do that?

Currently I have something like this, but I'm getting very confusing outputs and I don't think I fully understand what is happening when I'm calling throw new Meteor.Error(500, e.category_code, e.description);

In client.js

Meteor.call('firstCall', data, function (error, result) {
  if(result) {
    doSomething();
  }
  else{
    console.log(error);//just shows 500
  }
});

In server.js

var Future = Meteor.npmRequire("fibers/future");

function extractFromPromise(promise) {
    var fut = new Future();
    promise.then(function (result) {
        fut.return(result);
    }, function (error) {
        console.log(error);
        fut.throw(error);
    });
    return fut.wait();
}

firstCall: function (data){
  try{
    Meteor.call('secondCall', data, 'http://testhref.com/test', 'http://testhref2.com/test' function (error, result) {
      return result;
    });
  }
  catch(e){
    throw new Meteor.Error(500, e.category_code, e.description);
  }
}

secondCall: function (data, paymentHref, otherHref){
  try{
    var associate = extractFromPromise(balanced.get(paymentHref).associate_to_customer(otherHref).debit({
                "amount": data.paymentInformation[0].total_amount * 100,
                "appears_on_statement_as": "Trash Mountain"}));
  }
  catch(e){
    Collection.update(data.id, {
        $set: {
            'failed.category_code': e.category_code,
            'failed.description': e.description
        }
    });
    throw new Meteor.Error(500, e.category_code, e.description);
  }
}

Answer 1

In your case, the catch in firstCall is not going to have anything defined for e.category_code and e.description when secondCall throws. This is because in secondCall you are passing these two as arguments to Meteor.Error, which takes as its arguments error, reason, and details:

https://github.com/meteor/meteor/blob/devel/packages/meteor/errors.js

In order to pass these through, you will need to amend firstCall to use these properties:

firstCall: function (data){
  try{
    Meteor.call('secondCall', data, 'http://testhref.com/test', 'http://testhref2.com/test');
  }
  catch(e){
    throw new Meteor.Error(500, e.reason, e.details);
  }
}

I'm not even sure you need to split it up into two calls for modularity, as you can just use normal Javascript functions. But we can discuss that elsewhere.