both if and else condition are executed and both returns a result

Question

I have 2 data on my watcher field, first one has availability child and the second one doesn't have..

router.get('/getNewWatcher/:sdate/:shft/:type', function (req, res) {
    reqDate = req.params.sdate;
    reqShift = req.params.shft;
    reqType = req.params.type;

    var watcher = database.ref('watchers');

    watcher.once('value', function (snapshot) {
        var promises = [];

        snapshot.forEach(function (childSnapshot) {
            promises.push(new Promise((resolve, reject) => {
                resolve({
                    childKey: childSnapshot.key,
                    childData: childSnapshot.val()

                });
            }));
        });
        Promise.all(promises).then(function (snapshot) {
            var dataSet =[];

            snapshot.forEach(function (result) {
                if (result.childData.availability) {                            
                    dataSet.push({
                        child: result
                    })
                }else {
                    dataSet.push({
                        child: 'No Available Watchers'
                    })
                }
            });
            res.json(dataSet);
        })
    });
});

My code works.. when I run this script to check if a watcher has availability child it will return a watcher which has the availability child.. but for some reason else conditions also return 'No Available Watchers' so my problem is when I run this script both my if and else condition return a result which isn't quite what I'm looking for and I cant figure it out why.

Answer 1

Here is my Firebase architecture

I used same thing in Swift, here is its code maybe it's useful to understand.

    databaseRef.child("users").child(key).child("following").observeSingleEventOfType(.Value, withBlock: { snapshot in

        if let following = snapshot.value as? [String : AnyObject] {

            self.lblFollowing.text = String(following.count)

        } else {

            self.lblFollowing.text = "00"

        }
    })

Answer 2

From your comment chain with Jaromanda XI have the impression that you want to return a list of available watchers, or a single "No Available Watchers" when there are no watchers available anywhere.

To do this you have to move the "no watchers at all" detection outside of the loop:

var dataSet =[];

snapshot.forEach(function (result) {
    if (result.childData.availability) {                            
        dataSet.push({
            child: result
        })
    }
});

if (dataSet.length === 0) {
    dataSet.push({
        child: 'No Available Watchers'
    })
}

res.json(dataSet);