Reverse Google Maps geocoding with geohash for area of 3-letter hash accuracy

reverse-geocode-geohash.js

let NodeGeocoder = require('node-geocoder');
let geohash = require('latlon-geohash');

const options = {
  provider: 'google',
  httpAdapter: 'https',
  apiKey: process.env.GOOGLE_MAPS_KEY,
  formatter: null
};

let geocoder = NodeGeocoder(options);

let getCoordinates = (req, res) => {
  let location = req.params.location;

  geocoder.geocode(location).then((response) => {
    insertGeohashInResponse(response);
    res.json(response);
  }).catch((err) => {
    console.log(err);
  });
}

let insertGeohashInResponse = (response) => {
  let accurateHash = '';
  let shorterHash = '';
  
  for (var i = 0; i < response.length; i++) {
    accurateHash = geohash.encode(response[i].latitude, response[i].longitude);

    // shorterHash represents bigger area
    shorterHash = accurateHash.slice(0, 3);

    // inserts geohash in the response
    response[i].geohash = (lat && lon) ? shorterHash : null;
  }
}

module.exports = {
  getCoordinates
};