webhook/node_modules/es-abstract/2020/UTF16DecodeSurrogatePair.js

19 lines
781 B
JavaScript

'use strict';
var GetIntrinsic = require('get-intrinsic');
var $TypeError = GetIntrinsic('%TypeError%');
var $fromCharCode = GetIntrinsic('%String.fromCharCode%');
var isLeadingSurrogate = require('../helpers/isLeadingSurrogate');
var isTrailingSurrogate = require('../helpers/isTrailingSurrogate');
// https://ecma-international.org/ecma-262/11.0/#sec-utf16decodesurrogatepair
module.exports = function UTF16DecodeSurrogatePair(lead, trail) {
if (!isLeadingSurrogate(lead) || !isTrailingSurrogate(trail)) {
throw new $TypeError('Assertion failed: `lead` must be a leading surrogate char code, and `trail` must be a trailing surrogate char code');
}
// var cp = (lead - 0xD800) * 0x400 + (trail - 0xDC00) + 0x10000;
return $fromCharCode(lead) + $fromCharCode(trail);
};