RegExp test method string length limitation RangeError maximum call stack size exceeded

I have questions
1

I stumbled upon a string length limitation for the RegExp test method.
In fact, when I want to test whether a string is a valid Base64, I use this script.

const BASETEST = /^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$/gm;
BASETEST.lastIndex = 0;
BASETEST.test(''.padEnd(100,'A'))
// expected output: true

This works fine up until a string length of 4473905. When I want to parse a Base64 string that is longer, a RangeError is returned:

BASETEST.test(''.padEnd(4473906,'A'))
// returns Uncaught RangeError RangeError: Maximum call stack size exceeded at eval (repl:1:6)

Do you agree with me and what would be the way to get this fixed?

This is my very first topic in this group so please be patient with me.
Regards,

2

is there a reason not to just, try to decode it using atob?

1 Like
3

Thanks for the reply!

atob will definitely work in this scenario and I will also use it.

However in a different situation I want to make sure that RegExp does not cause the same issue on larger strings (text files).