replacement character can't be used in value

[ronderksen]

I have a field that takes an IBAN bank account number. These consist of 2 letters, 2 digits, 4 letters and 10 digits. I have react-input set up as follows:

const replacement = { _: /\d/, X: /[A-Z]/ };
const mask =  "XX __ XXXX ____ ____ __";

However, if I now want to type the letter X, the input is blocked, even though the replacement regex would allow it.

Is this a bug or am I using the library wrong?

[ronderksen]

For now I circumvented it by using an asterisk instead of the X.