example largest impacting hail

report_location.js

import * as turf from '@turf/turf';
import _ from 'lodash';

const geometry = {
    "type": "Point",
    "coordinates": [
        -73.92714109999997,
        40.8657281
    ]
};
const data = //Fetched map data....

const stage1 = []; //All impacting polygons.

data.forEach(map => {
  const { features, properties } = map;
  const impactingFeatures = [];

  features.filter(feature => !!feature.properties.hailSize).forEach(feature => {
    if (feature.geometry.type !== 'Polygon' || !turf.booleanWithin(geometry, feature)) {
      return;
    }
    const hailSize = feature.properties && feature.properties.hailSize;
    impactingFeatures.push(feature);
  });

  stage1.push([map, impactingFeatures]);
});
/* Largest impacting polygons (hailSize) per map (storm_date).
* stage2 = [ Date, HailSizeNumber ];
*/
const stage2 = [];
const hailSizeSelector = obj => Number(_.property('properties.hailSize')(obj))

stage1.forEach(([ map, impactingFeatures ]) => {
  const maxFeature = _.maxBy(impactingFeatures, hailSizeSelector);

  stage2.push([
    map.properties.storm_date,
    hailSizeSelector(
      maxFeature,
    ),
    _.pick(map, ['_id', 'properties', 'type']),
  ])
});

// Final Stage
results = _.unzip(stage2); // => Array<Array<StormDate>,Array<HailSize>>