Easily generate strings supplying a very simple pattern. '10-20:Xn/x/'.generate #>qBstvc6JN8ra. Generate random strings using a regular expression (Regexp): /[a-z0-9]{2,5}w+/.gen . Also generate words in English or Spanish. Perfect to be used in test data factories. Also, validate if a text fulfills a specific pattern or even generate a string following a pattern and returning the wrong length, value... for testing your applications.