Lightning Locker Service: Maximum call stack size exceeded on action getCallback()

Question

In the code bellow, the third parameter is a promise, that when resolved (or rejected) will execute a callback function.

There we receive a "Maximum call stack size exceeded" when Locker service is active.

var dataService = {
request : $A.getCallback(function(actionName, params, defer) {

    var componentActionName = 'c.' + actionName;
    var action = component.get(componentActionName);

    action.setParams(params);

    action.setCallback(this, function(a) {
        try {

            var state = a.getState();
            if (state === 'SUCCESS') {
                defer.resolve(a.getReturnValue());
            }
            else if (state === 'ERROR') {
                var errors = a.getError();
                if (errors) {
                    defer.reject(errors[0].message);
                } else {
                    defer.reject('Lightning server side unknown error');
                }
            }
        } catch (ex) {
            console.log('### Exception: ');
            console.log(ex);
        }
    });

    $A.enqueueAction(action);

})

Any idea what might be going on?

Answer 1

This has been fixed by Salesforce on SUMMER '16 PATCH 7.0

More details:

https://success.salesforce.com/issues_view?id=a1p3A000000jkqqQAA