Order of async function execution

I have a problem with handling the response of my async function in socket.io.

This is the main function, that I am dealing with.

return self.loadFiles()
            .then(resolve)
            .catch(reject)
            .then(_ => {
                socket.emit('RESPONSE', 'socketEmitResponse')
            })

loadFiles and serveFiles are both asyncFunctions. The Promise will eventually resolve here:

postAuthenticate : (socket) => {
    socket.on('syncEvent', function(data, callback) {

        return sync.syncThis(data)
        .catch(errorHandler)
        .then(callback('socketCallback'))

    })
}

Currently the response looks something like this:

> socketEmitResponse
> socketCallback

What I want is that the callback will execute first and then the emitResponse. How can I achieve that?

via Leonard Eyer