two functions tocheck if a text is emoji regular expression based and canvas based

isEmoji.js

// regular expression based
function isEmoji(text) {
	return (new RegExp(/[\uD800-\uDBFF]/g).test(text) && new RegExp(/[\uDC00-\uDFFF]/g).test(text));
}

// canvas bases, slow and depend if the system can draw the emoji
function isEmojiCanvas(text) {
	const ArrayLikeToString = arg => Array.prototype.toString.call(arg);
	const getTextFeature = (text, color) => {
		try {
			const canvas = document.createElement('canvas')
			canvas.width = 1;
			canvas.height = 1;
			const ctx = canvas.getContext('2d');
			ctx.textBaseline = 'top';
			ctx.font = '100px "Segoe UI Emoji", "Segoe UI Symbol", "Segoe UI", "Apple Color Emoji", "Twemoji Mozilla", "Noto Color Emoji", "EmojiOne Color", "Android Emoji"';
			ctx.fillStyle = color;
			ctx.scale(0.01, 0.01);
			ctx.fillText(text, 0, 0);
			return ctx.getImageData(0, 0, 1, 1).data
		} catch (e) {
			return false
		}
	}
	const feature1 = getTextFeature(text, '#000');
	const feature2 = getTextFeature(text, '#fff');
	if (feature1 && feature2) {
		const feature1Str = ArrayLikeToString(feature1)
		const feature2Str = ArrayLikeToString(feature2)
		return feature1Str === feature2Str && feature1Str !== '0,0,0,0';
	}
	return false;
}

const text = "😚 hello 🤭, how are you? 👌"

console.log("regular expression based:")

// don't use foreach
// or the emoji is splitted
for (const ch of text) {
    if (isEmoji(ch)) {
      console.log("is emoji", ch)
    }
    else {
      console.log("no is emoji", ch)
    }
}

console.log("canvas based based:")

// don't use foreach
// or the emoji is splitted
for (const ch of text) {
    if (isEmojiCanvas(ch)) {
      console.log("is emoji", ch)
    }
    else {
      console.log("no is emoji", ch)
    }
}