feat: make regex test strings smaller

By only evaluating the last path section on each pass

index.js

@@ -4,6 +4,6 @@ var path = require('path');
 var isglob = require('is-glob');
 
 module.exports = function globParent(str) {
-	while (isglob(str)) str = path.dirname(str);
+	while (isglob(path.basename(str))) str = path.dirname(str);
 	return str;
 };