shebang-regex 
Regular expression for matching a shebang line
Install
$ npm install shebang-regex
Usage
const shebangRegex = require('shebang-regex');
const string = '#!/usr/bin/env node\nconsole.log("unicorns");';
shebangRegex.test(string);
shebangRegex.exec(string)[0];
shebangRegex.exec(string)[1];
License
MIT © Sindre Sorhus