add: unit and integration testing

app/node_modules/shebang-command/index.js

@@ -0,0 +1,19 @@
+'use strict';
+const shebangRegex = require('shebang-regex');
+
+module.exports = (string = '') => {
+	const match = string.match(shebangRegex);
+
+	if (!match) {
+		return null;
+	}
+
+	const [path, argument] = match[0].replace(/#! ?/, '').split(' ');
+	const binary = path.split('/').pop();
+
+	if (binary === 'env') {
+		return argument;
+	}
+
+	return argument ? `${binary} ${argument}` : binary;
+};