Invalid chars for Buchungsstapel "Belegfeld 1"

[sunsations]

Another feedback we got from the DATEV-review

In den Belegfeldern sind folgende Zeichen zulässig:
Ziffern: 0 1 2...9
Großbuchstaben: A B C...Z
Kleinbuchstaben: a b c...z
Sonderzeichen: $ & % * + - /

Do you think it would make sense to validate or sanitize the input in the gem directly?
My proposal would be to throw an exception if the input contains invalid chars and leave the sanitization (Umlaut-Replacement and the like) to the caller.

[ledermann]

I've just add an additional regex validation. What do you think?

[sunsations]

Saw your commit and I like it 👍. The same rule also applies for Belegfeld 2 according to the information I got from DATEV.

See PR:
https://github.com/ledermann/datev/pull/15/files

[ledermann]

Merged, thanks a lot for your help!