Unicode(UTF-16) to UTF-8

index.js

function(text) {
	return text.replace(/[\uD800-\uDBFF][\uDC00-\uDFFF]|[\u0000-\uD7FF\uE000-\uFFFF]/g, function($, offset) {
		var isDoubleByte = $.length === 2
		var unicode = isDoubleByte ?
			(($.charCodeAt(offset) & 1023) << 10 | ($.charCodeAt(offset + 1) & 1023)) + 0x10000:
			$.charCodeAt(offset);
		return isDoubleByte ?
			String.fromCharCode(
				unicode >> 18 | 240,
				unicode >> 12 & 63 | 128,
				unicode >> 6 & 63 | 128,
				unicode & 63 | 128
			) :
			unicode < 128 ?
				String.fromCharCode(
					unicode
				) :
				unicode < 2048 ?
					String.fromCharCode(
						unicode >> 6 | 192,
						unicode & 63 | 128
					) :
					String.fromCharCode(
						unicode >> 12 | 224,
						unicode >> 6 & 63 | 128,
						unicode & 63 | 128
					);
	})
}