howto search in all mongodb collections (native driver)?

Question

I'm trying to search in all collections in one database but I have no idea howto return data at the end of the forEach cycle. I understand this is a place for Promise or async/await but don't know how to properly use it after forEach :-(

//db.js    
var MongoClient = require('mongodb').MongoClient;

    module.exports = {
      searchAllCollections: function() {
        return MongoClient.connect('mongodb://localhost:27017/nodeLists', {poolSize: 10}).then(function(db) {
          var ipList = [];
          db.listCollections().forEach((doc) => {
            console.log(doc.name);
            db.collection(doc.name).find({ip: "192.168.0.1"}).toArray((err, data) => {
              console.log(data);
              ipList.push(data);
            });
          });
        });
      }
    };


//app.js
var db = require('./db');

db.searchAllCollections().then(function(items) {
  console.info('Returned data:',items);
}, function(err) {
  console.error('The promise was rejected', err, err.stack);
});