• The methods should be static
• There're already many palindrome-related katas, and this one brings nothing new or interesting

I'd prefer using static methods or a constructor to pass the value as the default constructor looks useless in this case.

# Before
assertTrue(new PalindromeGenerator().isPalindrome("otto"));
assertEquals("otto", new PalindromeGenerator().generateString("otto"));

# After
assertTrue(PalindromeGenerator.isPalindrome("otto"));
assertEquals("otto", PalindromeGenerator.generateString("otto"));

OR

var palindrome = new PalindromeGenerator("otto");
assertTrue(palindrome.isPalindrome());
assertEquals("otto", palindrome.generateString());

JavaScript translation available. Please review and approve. I clarified the description and added more test cases, to include random tests.

Needs random tests

What should happend with spaces? i. e. Salta Lenin el Atlas or Dabale arroz a la zorra el abad
What should happend with non ASCII characters? Átale demoníaco Caín o me delata