winnow/lib/helpers/project-coordinates.js

Apply sql-like filters to GeoJSON

const proj4 = require('proj4')
const _ = require('lodash')
const transformCoordinates = require('./transform-coordinates')

module.exports = function projectCoordinates (params) {
  const { coordinates, fromSR = 'EPSG:4326', toSR } = params

  if (!toSR || fromSR === toSR) return coordinates

  return transformCoordinates(coordinates, { fromSR, toSR }, (coordinates, options) => {
    if (_.isNumber(coordinates[0]) && _.isNumber(coordinates[1])) {
      return proj4(options.fromSR, options.toSR, coordinates)
    }
    return coordinates
  })
}