es-toolkit/dist/compat/_internal/unicodeSize.js

A state-of-the-art, high-performance JavaScript utility library with a small bundle size and strong type annotations.

//#region src/compat/_internal/unicodeSize.ts
/**
* Counts the number of visible symbols (grapheme clusters) in a Unicode `string`,
* combining surrogate pairs, combining marks, variation selectors, Fitzpatrick
* modifiers, regional-indicator pairs, and zero-width-joiner sequences into a
* single symbol.
*
* Ported from lodash to preserve identical behavior.
* @link https://github.com/lodash/lodash/blob/4.17.21-es/_unicodeSize.js
*/
const rsAstralRange = "\\ud800-\\udfff";
const rsComboRange = "\\u0300-\\u036f\\ufe20-\\ufe2f\\u20d0-\\u20ff";
const rsVarRange = "\\ufe0e\\ufe0f";
const rsAstral = `[${rsAstralRange}]`;
const rsCombo = `[${rsComboRange}]`;
const rsFitz = "\\ud83c[\\udffb-\\udfff]";
const rsModifier = `(?:${rsCombo}|${rsFitz})`;
const rsNonAstral = `[^${rsAstralRange}]`;
const rsRegional = "(?:\\ud83c[\\udde6-\\uddff]){2}";
const rsSurrPair = "[\\ud800-\\udbff][\\udc00-\\udfff]";
const rsZWJ = "\\u200d";
const reOptMod = `${rsModifier}?`;
const rsOptVar = `[${rsVarRange}]?`;
const rsOptJoin = `(?:${rsZWJ}(?:${[
	rsNonAstral,
	rsRegional,
	rsSurrPair
].join("|")})${rsOptVar}${reOptMod})*`;
const rsSeq = rsOptVar + reOptMod + rsOptJoin;
const rsSymbol = `(?:${[
	`${rsNonAstral}${rsCombo}?`,
	rsCombo,
	rsRegional,
	rsSurrPair,
	rsAstral
].join("|")})`;
const reUnicode = RegExp(`${rsFitz}(?=${rsFitz})|${rsSymbol}${rsSeq}`, "g");
function unicodeSize(str) {
	let result = 0;
	reUnicode.lastIndex = 0;
	while (reUnicode.test(str)) ++result;
	return result;
}
//#endregion
exports.unicodeSize = unicodeSize;