how to test response in a callback inside a method inside a method?

gistfile1.txt

'sendMail': function(mailBody,maiSubject,mailTo, sendAt){

		if(mailTo == 'string'){
			mailTo = formatMailTo(mailTo);
		}
		
		var message = {
		    "html": mailBody,
		    "text": mailBody,
		    "subject": maiSubject,
		    "from_email": "noreply@foobarsatanico.com",
		    "from_name": "foobarsatanico",
		    "to": mailTo
		};

		Mandrill.messages.send({"message": message, "async": false, "send_at": sendAt }, function(result) {
		    console.log(result);
		    return result;
		}, function(e) {
		    console.log('A mandrill error occurred: ' + e.name + ' - ' + e.message);
		    return e.message;
		});
	}

The var "e" is a object containing erro occurred.
Mandrill Messages

Inject a callback an return result.

sendMail: function(mailBody,maiSubject,mailTo, sendAt, callback) {

    if(mailTo == 'string'){
        mailTo = formatMailTo(mailTo);
    }

    var message = {
        "html": mailBody,
        "text": mailBody,
        "subject": maiSubject,
        "from_email": "noreply@foobarsatanico.com",
        "from_name": "foobarsatanico",
        "to": mailTo
    };

    Mandrill.messages.send({"message": message, "async": false, "send_at": sendAt }, function(result) {
        console.log(result);
        callback(result);
    }, function(e) {
        console.log('A mandrill error occurred: ' + e.name + ' - ' + e.message);
        callback(e.message);
    });
}

OR use Promise. 😃