Return from async function in hapi route

Question

Using hapi v17

---

i have a route

    { 
        method: 'GET', 
        path: '/redirectEbay', 
        handler: registerController.ebayRedirect
    }

that leads to a controller

        ebayRedirect: function ebayRedirect(request, reply) {


            ebay.xmlRequest({
                serviceName: 'Trading',
                opType: 'GetSessionID',
                appId: EBAY_CLIENT ,      
                devId: EBAY_DEV ,
                certId: EBAY_SECRET ,
                params: {
                    RuName: EBAY_RUNAME
                }
            },
            function(error, data) {

                console.log(data);
                console.log(error);

                sessionID = data.sessionID;
                //catch ???
            });

            return (SessionID);

    }

and then of course SessionID is undefined as its generated from an async function.

Attemp with async / await:

        ebayRedirect: async function ebayRedirect(request, reply) {

            const session = await ebay.xmlRequest({
                ...
                params: {
                    RuName: EBAY_RUNAME
                }
            }, function(error, data) {

                sessionID = data.sessionID;
                return sessionID;
            });

            return (session);
        }

It gives another error, looklike the whole handler is considered malformed because not returning someting ?

the async call is correct and returning the session

Debug: internal, implementation, error 
Error: ebayRedirect method did not return a value, a promise, or throw an error

Another try with a different taste, still not resolving, like the await does not wait function to resolve as console.log is triggered immediately

At least got rid of the Error 500...

also tried a variation :

ebayS = async function() {

---

console.log ( ebay() );

gives

Promise { undefined }

Answer 1

The ebay.xmlRequest function uses a callback instead of a promise, so you have to wrap it in a promise:

ebayRedirect: function ebayRedirect(request, reply) {
  return new Promise((resolve, reject) => ebay.xmlRequest({
      params: {
        RuName: EBAY_RUNAME
      }
    },
    function(error, data) {
      if (error) {
        reject(error);
      } else {
        resolve(data.sessionID);
      }
    }
  ));
}