Check If Data Exists Using Firebase Function

How can I check if the days node exists using Firebase Cloud Function? Pseudo-code inside index.js: if(days.exists()) { //do something }

Solution 1:

// outside of function body
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);

// inside function body
return admin.database().ref('days').once('value').then(snap => {
  if (snap.exists()) {
    // do something
  }
});