source: trip-planner-front/node_modules/code-point-at/index.js@ fa375fe

/* eslint-disable babel/new-cap, xo/throw-new-error */
'use strict';
module.exports = function (str, pos) {
        if (str === null || str === undefined) {
                throw TypeError();
        }

        str = String(str);

        var size = str.length;
        var i = pos ? Number(pos) : 0;

        if (Number.isNaN(i)) {
                i = 0;
        }

        if (i < 0 || i >= size) {
                return undefined;
        }

        var first = str.charCodeAt(i);

        if (first >= 0xD800 && first <= 0xDBFF && size > i + 1) {
                var second = str.charCodeAt(i + 1);

                if (second >= 0xDC00 && second <= 0xDFFF) {
                        return ((first - 0xD800) * 0x400) + second - 0xDC00 + 0x10000;
                }
        }

        return first;
};