一个 Emoji 为什么不止一个字符：拆解肤色、旗帜与 ZWJ

const text = "👩🏽‍💻";
const parts = [...new Intl.Segmenter("zh", {
  granularity: "grapheme"
}).segment(text)].map(part => part.segment);
console.log(text.length); // 7 UTF-16 code units
console.log([...text].length); // 4 code points
console.log(parts.length); // 1 grapheme cluster
console.log([...text].map(char =>
  "U+" + char.codePointAt(0).toString(16).toUpperCase()
)); // U+1F469, U+1F3FD, U+200D, U+1F4BB