export function _getHaversineDistanceBetweenLocations()

in packages/@fbcmobile-ui/Utils/MapUtils.js [49:78]

• 26 lines of code
• 7 McCabe index (conditional complexity)

export function _getHaversineDistanceBetweenLocations(
  point1: ?Coords,
  point2: ?Coords,
): ?number {
  if (
    point1 == null ||
    point2 == null ||
    point1.latitude == null ||
    point1.longitude == null ||
    point2.latitude == null ||
    point2.longitude == null
  ) {
    return null;
  }
  // Lat/Lng are given as degrees, so we convert to radians.
  const lat1 = point1.latitude * DEGREES_TO_RADIANS;
  const long1 = point1.longitude * DEGREES_TO_RADIANS;
  const lat2 = point2.latitude * DEGREES_TO_RADIANS;
  const long2 = point2.longitude * DEGREES_TO_RADIANS;

  const latDiff = lat1 - lat2;
  const lngDiff = long1 - long2;

  const h =
    _haversine(latDiff) + Math.cos(lat1) * Math.cos(lat2) * _haversine(lngDiff);

  const distance = TWICE_EARTH_RADIUS * Math.asin(Math.sqrt(h));

  return distance;
}