Retrieve data from Firestore to display in DialogFlow

Question

I am trying to get data from firestore and display it in DialogFlow response. When i trigger "buyerBusiness" intent in DialogFlow, the function web fulfillment is successful but the data retrieved does not display as response. It comes in logs when i console them. Below is the handler function written for the same.

function buyerBusiness(agent) {
        console.log("buyer name is " + params.BuyerEntity);
        var abc = new Set();
        var results = [];
        admin.firestore().collection('SuppBuyAssoc').where('Advertiser', '==', params.BuyerEntity).limit(5).get().then(snapshot => {
            snapshot.forEach(doc => {
                abc.add(doc.data().Agency);
            });
            var x = Array.from(abc);
            var y;
            for (var j = 0; j < x.length; j++) {
                y = results.push(x[j]);
            }

            blueBird.all(results).then(function () {
                console.log('results are: ' + results);
                agent.add(results);
            }).catch(eror => {
                console.log("Errrrr");
                console.log(eror);
            })
            console.log("results are:"+ results);

        }).catch(reason => {
            // res.send(reason)
            console.log(reason);
        })

        // agent.add(`Testing this stuff`);
    }

Here are logs for cloud functions -

3:32:33.069 PM info dialogflowFirebaseFulfillment results are: Publicis,Ogilvy,GroupM,WPP
3:32:32.668 PM info dialogflowFirebaseFulfillment results are:Publicis,Ogilvy,GroupM,WPP
3:31:55.910 PM
outlined_flag   
dialogflowFirebaseFulfillment
Function execution took 2930 ms, finished with status code: 200
3:31:54.253 PM
info    
dialogflowFirebaseFulfillment
buyer name is IBM
3:31:54.253 PM
info    
dialogflowFirebaseFulfillment
Dialogflow Request body: ----------
3:31:54.247 PM
info    
dialogflowFirebaseFulfillment
Dialogflow Request headers: ---------
3:31:52.981 PM
outlined_flag   
dialogflowFirebaseFulfillment
-------
3:31:52.981 PM
outlined_flag   
dialogflowFirebaseFulfillment
Function execution started

Answer 1

For the Dialogflow fulfillment library to keep track of your async request, you need to return the promise you got from calling firestore.

Try adding return before the admin.firestore().collection call:

function buyerBusiness(agent) {
  console.log("buyer name is " + params.BuyerEntity);
  var abc = new Set();
  var results = [];
  return admin.firestore().collection(/* rest of code */