generator-website-starter/generators/app/templates/node_modules/is-jpg/index.js

A website generator using semantic markup, SASS, Gulp, Imagemin and Browser-sync

'use strict';
module.exports = buffer => {
	if (!buffer || buffer.length < 3) {
		return false;
	}

	return buffer[0] === 255 &&
		buffer[1] === 216 &&
		buffer[2] === 255;
};