text: import { getAstralNumberFromSurrogatePair, isHighSurrogate, isLowSurrogate } from 'helper/string/surrogate_pair';
  import coerceToNumber from 'helper/number/coerce_to_number';
  import coerceToString from 'helper/string/coerce_to_string';
  import nanDefault from 'helper/number/nan_default';
  
  /**
   * Get the Unicode code point value of the character at `position`. <br/>
   * If a valid UTF-16 <a href="https://rainsoft.io/what-every-javascript-developer-should-know-about-unicode/#24surrogatepairs">
   * surrogate pair</a> starts at `position`, the
   * <a href="https://rainsoft.io/what-every-javascript-developer-should-know-about-unicode/#astralplanes">astral code point</a>
   * value at `position` is returned.
   *
   * @function codePointAt
   * @static
   * @since 1.0.0
   * @memberOf Chop
   * @param  {string} [subject=''] The string to extract from.
   * @param  {number} position The position to get the code point number.
   * @return {number} Returns a non-negative number less than or equal to `0x10FFFF`.
   * @example
   * v.codePointAt('rain', 1);
   * // => 97, or 0x0061
   *
   * v.codePointAt('\uD83D\uDE00 is smile', 0); // or '😀 is smile'
   * // => 128512, or 0x1F600
   */
  export default function codePointAt(subject, position) {
    const subjectString = coerceToString(subject);
    const subjectStringLength = subjectString.length;
    let positionNumber = coerceToNumber(position);
    positionNumber = nanDefault(positionNumber, 0);
    if (positionNumber < 0 || positionNumber >= subjectStringLength) {
      return undefined;
    }
    const firstCodePoint = subjectString.charCodeAt(positionNumber);
    let secondCodePoint;
    if (isHighSurrogate(firstCodePoint) && subjectStringLength > positionNumber + 1) {
      secondCodePoint = subjectString.charCodeAt(positionNumber + 1);
      if (isLowSurrogate(secondCodePoint)) {
        return getAstralNumberFromSurrogatePair(firstCodePoint, secondCodePoint);
      }
    }
    return firstCodePoint;
  }