Google Maps PolyUtil utils, and its tests, ported from Java.
npm install --save google-maps-polyutilvar polyutil = require('google-maps-polyutil')
var locations = [{latitude: 51, longitude: 0}, {latitude: 51, longitude: 0}, {latitude: 52, longitude: 0}, {latitude: 52, longitude: 0}]
// Simplification
var simplifiedLocations = polyutil.simplify(locations)
// Encode to string
var polyline = polyline.encode(simplifiedLocations)
// Decode from string
var decodedLocations = polyutil.decode(polyline)