export function geohashQuery()

in packages/geofire-common/src/index.ts [316:335]

• 19 lines of code
• 3 McCabe index (conditional complexity)

export function geohashQuery(geohash: Geohash, bits: number): GeohashRange {
  validateGeohash(geohash);
  const precision = Math.ceil(bits / BITS_PER_CHAR);
  if (geohash.length < precision) {
    return [geohash, geohash + '~'];
  }
  geohash = geohash.substring(0, precision);
  const base = geohash.substring(0, geohash.length - 1);
  const lastValue = BASE32.indexOf(geohash.charAt(geohash.length - 1));
  const significantBits = bits - (base.length * BITS_PER_CHAR);
  const unusedBits = (BITS_PER_CHAR - significantBits);
  // delete unused bits
  const startValue = (lastValue >> unusedBits) << unusedBits;
  const endValue = startValue + (1 << unusedBits);
  if (endValue > 31) {
    return [base + BASE32[startValue], base + '~'];
  } else {
    return [base + BASE32[startValue], base + BASE32[endValue]];
  }
}