xregexp having different result

I want to validate string with rules:

• string must contain at least one letter
• string can contain only those symbols(but it's not a must): ' , - , ( , )
• if there is a symbol present in the string, it must also contain a letter(at least one 1st bullet)
• only symbols are not allowed

so far I have come up with the following regex:

    static personName = XRegExp.cache("^[\\s\\p{L}\\'\\-\\(\\)]+(?=\\S*\\p{L})\\S+$");

which doesn't work correctly. Only "^(?=\\S*\\p{L})\\S+$" this helps with the letters, I struggle to understand how to add symbols to it so that all rules will be passed, what am I doing wrong?

If the chars you allow are restricted to those you enumerated you may use

var regex = XRegExp("^[\\s'()-]*\\p{L}[\\s\\p{L}'()-]*$"); 

If you want to allow any chars but only a subset of symbols, with "at least 1 letter" restriction use

var regex = XRegExp("^[\\p{N}\\s'()-]*\\p{L}[\\p{L}\\p{N}\\s'()-]*$"); 

See the JS demo:

var regex = XRegExp("^[\\s'()-]*\\p{L}[\\s\\p{L}'()-]*$");
console.log( regex.test("Sóme (unknown-string) doesn't like it") );

var regex = XRegExp("^[\\p{N}\\s'()-]*\\p{L}[\\p{L}\\p{N}\\s'()-]*$"); 
console.log( regex.test("Sóme unknown-string (123)") );

<script src="https://cdnjs.cloudflare.com/ajax/libs/xregexp/3.2.0/xregexp-all.min.js"></script>

Details

• ^ - start of string
• [\\s'()-]* - 0 or more whitespaces, ', (, ) or - chars
• [\\p{N}\\s'()-]* - 0 or more digits, whitespaces and the allowed symbols
• \\p{L} - a letter
• [\\s\\p{L}'()-]* - 0 or more whitespaces, letters, ', (, ) or - chars
• [\\p{L}\\p{N}\\s'()-]* - 0 or more letters, digits, whitespaces and the allowed symbols
• $ - end of string.