winnow/lib/filter-and-transform/transforms/to-geohash.js

Apply sql-like filters to GeoJSON

const { encode } = require('ngeohash')
const { default: centroid } = require('@turf/centroid')

function transformToGeohash (geometry = {}, precision = 8) {
  const { type, coordinates } = geometry
  if (!type || !coordinates) return

  let centroidGeometry

  if (type !== 'Point') {
    centroidGeometry = centroid(geometry)
  }
  const { coordinates: geohashTarget } = centroidGeometry || geometry
  return encode(geohashTarget[1], geohashTarget[0], precision)
}

module.exports = transformToGeohash